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An official publication of the National Institute of Building SciencesBuilding Enclosure Technology and Environment Council (BETEC)

Journal of Building Enclosure Design

JBEDWinter 2013

National Institute of Building Sciences: An Authoritative Source of Innovative Solutions for the Built Environment

Thermal Bridging:

It Can Be DoneBetter


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Winter 2013 5

Contents

JBEDPublished For:he National Institute of BuildingSciences Building Enclosure echnology andEnvironment Council1090 Vermont Avenue, NW, Suite 700

Washington, DC 20005-4905Phone: (202) 289-7800Fax: (202) [email protected]

www.nibs.org

PRESIDENHenry L. Green, Hon. AIA

CHIEF OPERAING OFFICEREarle W. Kennett

PUBLISHED BY:Matrix Group Publishing Inc.Please return all undeliverable addresses to:5190 Neil Road, Suite 430Reno, NV 89502Phone: (866) 999-1299Fax: (866) 244-2544

PRESIDEN & CEOJack Andress

CHIEF OPERAING OFFICERJessica Potter

[email protected]

PUBLISHERPeter Schulz

EDIOR-IN-CHIEFShannon [email protected]

EDIORAlexandra Walld

FINANCE/ACCOUNING &ADMINISRAION

Shoshana Weinberg, Pat Andress,Nathan [email protected]

DIRECOR OF MARKEING &CIRCULAIONShoshana Weinberg

SALES MANAGER WINNIPEGNeil Gottfred

SALES MANAGER HAMILONBrian Davey

MARIX GROUP PUBLISHING INC.ACCOUN EXECUIVESRick Kuzie, Brian MacIntyre, Brodie Armes,Christopher Smith, David Roddie, DeclanODonovan, Jeff Cash, Jim Hamilton, KenPercival, Monique Simons, Rick Kuzie, Robert

Allan, Robert Choi, Ronald Guerra, WilmaGray-Rose, John Price, Colleen Bell

ADVERISING DESIGNJames Robinson

LAYOU & DESIGNravis Bevan

2012-2013 Matrix Group Publishing Inc. Allrights reserved. Contents may not bereproduced by any means, in whole or in part,without the prior written permission of thepublisher. he opinions expressed inJBEDarenot necessarily those of Matrix GroupPublishing Inc. or the National Institute ofBuilding Sciences/Building Enclosureechnology and Environment Council.

An official publication of theNational Institute ofBuil dingScBuilding EnclosureTechnology and EnvironmentCouncil (

Journal of Building Enclosure D

JBEDWinter 2013

NationalInstituteofBuildingSciences: An AuthoritativeSourceofInnovativeSolutions for the Built E

Thermal BridgIt Can Be D

BeMessages:

07 Message from InstitutePresident Henry L. Green

09

Message from BETECChairman Wagdy Anis

Industry Updates:

27 BEC Corner

32 Buyers Guide

Feature:

11 Heat TransferNumerical ModelingPerspectives: Steel-

Framed Wall Analysis

15Thermal Bridging:Ignorance is not Bliss

18 The Truth is Out There:Efficiency and IconicArchitecture Can

Co-Exist

23 Thermal Bridging: TheFinal Frontier of High-Performance Buildings

On the cover:The Cenfor Interactive Research

Sustainability (CIRS), loca

the University of British

Columbia, is one of the

greenest buildings on ear

and provides a great exam

of thermal bridging done


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Winter 2013 7

Message from the National Institute of Building Sciences

Henry L. Green, Hon. AIA

I HAS BEEN A BUSY SUMMER AND

fall. Since my last column, I had the op-

portunity to meet with members of Greater

Detroits Building Envelope Council (BEC-GD). Not only was it good to be back in

Michigan, it was good to meet with mem-

bers of the Detroit BEC, whom I worked

with for so many years while serving as

Director of Michigans Construction Codes

Program.

While at the BEC-GD September

Meeting, I was privileged to present

discussions along with Fiona Aldous, Dr.

Teresa Weston and Chris Mathis. Te

event included some 200-plus members

of BEC-GD and a number of vendors who

displayed their services. I focused mydiscussion on the role that the National

Institute of Building Sciences, the Building

Enclosure echnology and Environment

Council (BEEC) and local BECs share in

developing sound, scientific discussion on

envelope protection and the integration

of measures that yield high performing

resilient buildings and communities. I

want to thank the members and officers of

BEC-GD for their gracious hospitality and

a willingness to become a part of a nation-

wide effort to improve the building process

and the built environment.I also wanted to follow up on the

discussion I began in the Summer issue of

the Journal of Building Enclosure Design

(JBED)regarding the code proposals being

advanced in the International Codes to

address the use of foam plastics in exterior

wall systems and vertical and lateral fire

propagation.

Our proposal to address the use of foam

plastics in exterior wall systems was not

accepted but we were able to initiate a good

dialogue. While the Institute was unableto get this included in the next edition

of the codes, we will try again at the next

opportunity to make the necessary revisions

to allow for the use of foam plastics in

exterior wall assemblies, to create a system

that provides for both fire safety and thermal

resistance in building envelopes.

Te good news is that the revision to

the vertical and lateral fire propagation

section of the code was accepted. It allows

for the use of combustible water resistant

barriers without the need for a fire test

under National Fire Protection Association(NFPA) 285 in certain instances.

Leading up to this, a meeting was

convened to discuss the proposed revisions

with all of the parties of interest. I want to

thank all of the participants in this effort

who worked to find a common resolution

to this issue.

Unfortunately, our effort to revise the

code provisions of Section 2603.5 was

not successful. his proposed change

would have reformatted the section for

foam plastics and modified it to allow

for fireblocking as an alternative totesting. o overcome the committee

recommendation for disapproval, a 2/3

majority of the voting members was

required to hear the public comment to

include our revisions. he attempt to

overturn was not successful. However,

I believe this discussion provides the

basis for ongoing discussions and we

can revisit this issue over the next year

to resubmit the revision for the next

round of code hearings. Unfortunately,

that is not until 2016. I would challengethe BEEC to take up this discussion

and formulate a plan of support for a

resubmission.

I would also like to encourage you to

attend Building Innovation 2013, which

is the Institutes Conference & Expo. It is

scheduled for January 7-11, 2013, at the

Washington Marriott at Metro Center in

Washington, D.C. Tis is also where BEEC

Symposium, Fenestration: A World of

Change, will be held. Tis event will include

leading experts in building enclosure

research, design and practice who will uniteto tackle the latest issues. Te council, which

is celebrating its 30th year, will present the

most current data available on fenestration

performance and technology.

I look forward to seeing you there.

Henry L. Green, Hon. AIA

President

National Institute of Building Sciences


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Winter 2013 9

Wagdy Anis, FAIA, LEED-AP

Message from the Building Enclosure Technology and Environment Council

WELCOME O HE 2013 WINER EDIION

of the Journal of Building Enclosure Design

(JBED). Tis edition is dedicated to thermal

bridges in buildings, which are buildingcomponents made of conductive build-

ing materials, such as aluminum, steel and

concrete. Tese materials bridge across the

continuous thermal insulation barrier in

building enclosures. Termal bridges can

have a considerable negative impact on en-

ergy efficiency, which youll read about in

the articles in this edition.

Te United States is facing a nationwide

problem, yet there are no current code re-

quirements to define, quantify, regulate

or control thermal bridges in buildings. In

addition to the energy impact of thermalbridges, there are potential health and du-

rability concerns associated with moisture

accumulation and condensation. Tere are

human comfort problems associated with

cold surfaces indoors. Tere are also aes-

thetic concerns associated with the disfig-

urement of faades because of the growth

of microorganisms and the accumulation

of dust and soot associated with Brownian

motion, due to temperature differentials in-

doors. Tis can only be described as a bad

deal for the many good aspects of building

enclosure design. Why do we let this contin-

ue, when energy independence and securi-

ty require reducing the energy consumption

of buildings?

Interestingly, Oak Ridge National Labo-

ratory, one of the research laboratories of

the U.S. Department of Energy, commis-

sioned a study published in 1989, entitled,

Catalog of Termal Bridges in Commercial

and Multi Family Residential Construction.

It identified and quantified many of the

common thermal bridges that are still be-

ing designed today, in addition to the many

more that the ingenuity of the design and

construction community has devised since

then. Yet, the sustainability codes, the Inter-

national Green Construction Code (IgCC)

and ASHRAE 189.1, as well asLeadership inEnergy and Environmental Design (LEED),

or the New Buildings Institutes Core Perfor-

mancehave still to address this issue.

ASHRAE recently commissioned a re-

search project, Termal Performance of

Building Envelope Details for Mid- and

High-Rise Buildings (1365-RP), which stud-

ied common thermal bridges in buildings,

quantified their energy impact and pro-

posed approaches to simplifying the types

of thermal bridges. I believe we need to

do some more work to identify acceptable

strategies that minimize thermal bridges re-sulting from fastening cladding onto build-

ings through continuous insulation layers.

We then need to identify and quantify the

three types of bridges described in 1365-RP

and legislate maximum allowable amounts

of such details in buildings.

Tere are solutions available today for

thermally breaking major structural compo-

nents that protrude beyond the insulation.

What remains is the multitude of enclosure

components that are non-primary struc-

tures, such as cladding, trim, cornice and

parapet attachments, solar shading devic-

es, as well as steel mechanical equipment

dunnage on roofs (for example, why are we

not using fiberglass structural sections?)

and aesthetic visual screens of mechanical

equipment. Fall protection tie-backs can

also be another challenge.

Tis subject is complicated. I believe

that codes in the United States try to sim-

plify the requirements so that designers

can more easily comply with codes and

building officials can more easily control

whats going on. England dealt with this

problem head-on in its building require-

ments, which require calculations for ther-

mal bridges. I believe the United States

needs to do the same. Life may become

more complex as we reach out to deal withthis type of low-hanging fruit from an

energy conservation and better building

perspective, but we need to bite the bullet.

aking the lead from our earlier efforts with

water-resistant barriers, we should develop

code proposals to address this issue in the

next code cycle.

On another note, please pencil April 18

and 19, 2013, into your calendars and make

sure to attend the Air Infiltration and Venti-

lation Centres (AIVC) conference, which is

sponsored by the Building Enclosure ech-

nology and Environment Council (BEEC).It will be held in the Washington, D.C.,

area. Te conference is being organized by

the Belgian-based International Network

for Information on Ventilation and Energy

Performance, for the Air Infiltration and

Ventilation Centre, and includes a track de-

veloped by BEEC that specifically focuses

on the United States. (Since air tightness of

buildings is now a code requirement.)

Another major event is the Seattle North-

west Regional Building Enclosure Confer-

ence, entitled, Zen and the Art of Building

Enclosure Design, which will be held at the

Seattle Art Museum on May 21, 2013. It is

being organized by the Portland and Seattle

Building Enclosure Councils. BEEC will be

holding its Board meeting the day preceding

this event.

I hope to see you at these events!

Wagdy Anis, FAIA, LEED-AP

Chairman, BEEC

PrincipalWiss, Janney, Elstner Associates, Inc.

Life may become more complex as we reachout to deal with this type of low-hanging fruit

from an energy conservation and better buildingperspective, but we need to bite the bullet. aking

the lead from our earlier efforts with water-resistantbarriers, we should develop code proposals to

address this issue in the next code cycle.


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Winter 2013 11

Feature

IN RECEN YEARS, HE BUILDING

industry has established priorities tomove towards the construction of highly

energy-efficient buildings, including the

prevention or mitigation of thermal bridg-

es. In the past, when building energy effi-

cient wasnt such an issue, thermal bridge

problems were considered to be insignifi-

cant or negligible, given that the rest of the

losses through a building envelope were

dominated by the lack of insulation imple-

mentations, infiltration, etc.

oday, as the industry improves the

thermal barrier in those areas of the build-ing denominated as clear wallthose

parts which are free from doors, windows

or any other protrusion mainly for struc-

tural purposesthe thermal bridge effects

tend to be more noticeable. Now that there

is a more pressing need to determine how

influential the thermal bridge effects can

be at various building connection details,

the computational modeling approach has

been shown to be an attractive method. It

can achieve reliable results that cant be de-

termined by physical measurements, such

as temperatures inside a composite wallstructure or within a building foundation.

Among other sources, the Assessment

and Improvement of the EPBD Impact

(ASIEPI) project has compiled a number

of software programs relating to modeling

thermal bridges. Te project is designed

to give an overview of the status and prog-

ress of the many European Union energy

initiatives. Stemming from this work, this

article independently evaluates a ther-

mal bridge scenario using two software

programs that have different levels of

capabilities.

Te selected software programs comply

with Standard ISO 10211: Termal bridges

in building constructionHeat flows and

surface temperaturesDetailed calcula-

tions. Tis standard defines requirementsfor 2D and 3D numerical heat transfer soft-

ware used to determine the heat transfer

effects associated with thermal bridges. Ac-

cording to ISO 10211, the thermal bridging

modeling software should be able to repli-

cate the calculated heat flow and tempera-

tures for a standard set of thermal bridge

scenarios.

Te first selected software, COMSOL

Multiphysics Finite Element Analysis

(FEA) Simulation software, was chosen

for its extensible methods for defining themodel geometry and its amenability to

non-linear material properties. Te sec-

ond software, HEA3, Finite Difference

Method (FDM)-based software, was se-

lected for its concise capability to handle

rapid 3D steady state and transient simu-

lations. It also includes a materials library

with more than 200 common building

materials.TABLE 1compares some of the

features of both software programs.

ANALYSIS

ASHRAE RP-1365 Termal Perfor-mance of Building Envelope Details for

Mid- and High-Rise Buildings references

two separate works; the first one conduct-

ed by Desjarlais and McGowan (Compari-

son of experimental methods to evaluate

thermal bridges in wall systems, 1997) and

the second one by Brown and Stephenson

(Guarded hot box measurements of the dy-

namic heat transmission characteristics of

seven wall specimen-part II, 1993). Tese

studies were performed in the Building

echnologies Research and Integration

Center, a division of Oak Ridge National

Laboratory (ORNL). In summary, the

test procedure, known as Hotbox est-

ing, consists of placing a large building

section (in this case, an 8 ft. by 8 ft. wall)

inside a calibrated apparatus that, in turn,measures heat transfer based on heat and

temperature inputs. Wind flow inside the

apparatus can also be controlled by the

tester. For the present analysis, RP-1365

referenced steady state and transient data

were selected. Tis data was used to deter-

mine the analyzed specimen R-value. Tis

has been used as a baseline to compare

the HEA3 and COMSOL models. A wall

section schematic is shown in FIGURE 1.

Te HEA3 and COMSOL models

share several common simplificationswith respect to the physical specimens.

Te vertical steel studs and horizontal rails

were assumed to be a single, continuous

component, eliminating the rail flange

over vertical stud flange configuration.

No screws or any other joint component

were included in either model. Te rest of

the dimensions were modeled exactly as

stated in the references.

Also, the steady state and transient

models mesh was manually refined on

Heat Transfer Numerical Modeling

Perspectives: Steel-Framed Wall AnalysisBy Axy Pagn-Vzquez and Jeff Allen

TABLE 1: HEAT3 AND COMSOL MULTIPHYSICS FEATURE COMPARISON

Software Name Relative Price 3-D Modeling?Non-linear material property

modeling?

Termo-fluid

modeling?

ransient

Simulation?

COMSOL High Y Y Y Y

HEA3 Low Y N N Y

Figure 1. Steel-framed wall tested at ORNL

and modeled on HEA3 and COMSOL.

Dimension units given in millimeters. Not

shown to scale.


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12Journal of Building Enclosure Design

both software programs. Note that HEA3

considers surface film co-efficients ref-

erenced in the 2009 ASHRAE Handbook

- Fundamentals (34 W/m2-K for the cold/

exterior side and 8.3 W/m2

-K hot/interiorside of the modeled wall. Tese co-effi-

cients were not considered in the COM-

SOL models. Te steel studs were modeled

in COMSOL as highly conductive layers.

Tis user-selected option, in principle,

assumes no temperature gradients along

steel stud thickness direction. FIGURE 2

shows the temperature contour profiles

for COMSOL and HEA3. Te steel fram-

ing reveals its low temperature in relation

with the rest of the wall, as indicated by

the vertical orange stripes. Te high ther-mal conductivity of the studs causes a

much higher heat flux through them than

through the insulation, leading to a much

lower surface temperature.

Comparing the steady state results

from the Hotbox experiment, as well as

each of the two simulations, resulted in

the following R-values: 1.39 m K/W

(Hotbox), 1.41 m K/W (HEA3) and 1.49

m K/W (COMSOL). Both HEA3s and

COMSOLs R-value relative error stayed

under 10 percent. Te result deviationsare caused, in part, by the exclusion of the

contact resistance effects between mate-

rial surfaces, as well as the exclusion of

joint connectors, such as bolts, etc. RP-

1365 model validation analysis concludes

that contact resistance, such as steel-to-

steel interfaces and insulation interfaces,

Figure 2. COMSOL Multiphysics (left) and HEA3 (right) steady

state temperature contour profiles (both scales in C). Section

viewed from the interior side of the building.

Figure 3. Measured and computed wall heat flux during a 24-

hour period (COMSOL, HEA3 and Hotbox test results).


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Winter 2013 13

can have significant impacts on the over-

all wall thermal resistance, particularly

on steel stud assemblies without exterior

insulation. McGowan and Desjarlaiss

(1995) work demonstrates the relevant

contact resistance impact on steel stud

assemblies.

For the transient analysis, the total heat

transfer was evaluated for a period of 24hours. A fixed temperature value was set

at the inner wall surface, while a time-de-

pendent temperature was assigned to the

outer wall surface.

One notable difference between the

COMSOL and HEA3 transient models

was the chosen time step and the se-

lected initial temperature conditions. A

time step of one second and one hour

were selected for COMSOL and HEA3,

respectively. An homogeneous tem-

perature value of 32.9F (0.5C) was as-sumed for the entire wall system in the

COMSOL model, while a non-homoge-

neous field was assumed on the HEA3

model. Previous to the HEA3 transient

analysis, a quasi-steady state simulation

was performed to determine the tem-

perature field representative of the ini-

tial temperature conditions. As a result,

a location-dependent temperature field

was obtained and included in the mod-

el. Te transient simulation results were

compared with RP-1365 transient testing

data, based on Hotbox testing performedby Brown and Stephenson (1993). Tese

results are shown in FIGURE 3. Note that

all the mentioned possible factors influ-

encing the steady results discrepancy

also have influence over the transient

simulations.

Even though COMSOL and HEA3

solve the same partial differential

equation (heat diffusion equation), as

mentioned, they implement different

numerical techniques to solve it. Emerly

and Mortazavi (1982) conclude that FDM

heat balance appears to be best for prob-

lems in which continuity of the heat flux

is important, whereas FEM is best suited,

among other scenarios, in the examples

with concentrated heat sources. Also, the

exclusion of the surface film co-efficients

on the COMSOL model causes a sub-

estimation of the simulated total heat

transferred, consequently inducing an

over-estimated equivalent wall thermal

resistance.

CONCLUSIONS

Te software programs results were

specific for the selected scenario. Under-

standing that thermal bridging problems

are developed in building sections having

similar geometrical and composition pat-

terns, the use of HEA3, at least for this

particular simulation, appears to be a prac-

tical tool, considering its cost and similarityto the Hotbox results. Additional building

envelope models, however, should be con-

sidered in order to determine if the two

software programs consistently match ex-

perimental results, or if the results were

unique for this particular scenario. n

Axy Pagn-Vzquez is a mechanical

engineer at the U.S. Army Corps Engineer

Research and Development Center (ERDC),

Construction Engineering Research Labo-

ratory (CERL). He has been involved withheat transfer modeling of building envelope

sections as part of the laboratorys research

in prevention and mitigation of thermal

bridges in buildings. Hes currently pursu-

ing graduate studies focusing on numeri-

cal modeling aspects for fluid and solid

mechanics.

Jeff Allen is a research mechanical en-

gineer at ERDCs Information echnology

Laboratory. He holds advanced degrees

in mechanical and aerospace engineer-

ing as well as an undergraduate degree in

mathematics. His interests include high-performance computational modeling of

multiphysics and multi-scale systems.

REFERENCES

1. Assessment and Improvement of the

EPBD Impact (2010), An Effective

Handling of Termal Bridges in the

EPBD Context-Final Report.

2. Morrison Hershfield (2011), Termal

Performance of Building Envelope

Details for Mid- and High-Rise Build-

ings(RP-1365).3. International Standard Organiza-

tion (2007), ISO 10211:2007 Termal

bridges in building construction

Heat flows and surface tempera-

turesDetailed calculations.

4. Brown W. C. and Stephenson D. G.

(1993). Guarded hot box measure-

ments of the dynamic heat transmis-

sion characteristics of seven wall

specimens-part II. ASHRAE ransac-

tions 99, 643-660.

5. Desjarlais and McGowan. (1997).Comparison of Experimental and An-

alytical Methods to Evaluate Termal

Bridges in Wall Systems. 3rd ASM

Symposium on Insulation Materi-

als: esting and Applications: 3rdVol.

ASM SP 1320.

6. 2005 ASHRAE Fundamentals Hand-

book able 5, Chapter 3.

7. InfraMation 2006 Proceedings IC

115 A 2006-05-22.

8. Emerly and Mortazavi. (1982). A

Comparison of the finite differenceand finite element methods for the

heat transfer calculations.


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Winter 2013 15

Feature

ACROSS NORH AMERICA, HE INDUSRY

is facing more stringent thermal require-

ments in building codes, and designers are

responding by increasing the amount of

insulation in walls, all in an attempt to in-

crease energy efficiency in buildings. But

how effective are these changes on build-

ing energy use when the impacts of 3D heat

flow in transition building components (for

example, exposed concrete slabs, windowflashings and un-insulated parapets), are

ignored? What if the building components

that are neglected have a much greater im-

pact on energy than first realized? And how

will that affect the decisions that are current-

ly made regarding the building envelope?

Termal bridging cannot be com-

pletely avoided since many of these tran-

sition components, such as shelf angles

and canopy penetrations, are required for

structural purposes. Te building industry

has long struggled with how to deal with

analyzing these components from a ther-mal perspective. Te current thought pro-

cess is: If these structural members have

to be there, they are small compared to the

total wall area AND the energy impacts

are difficult to calculate, so they can be

ignored and focus can be put elsewhere.

Tis has resulted in codes and standards

increasing the thermal resistance require-

ments of walls and windows (lowering

maximum wall U-values), while largely

neglecting heat flow between transitional

components.

More often than not, this increase in

thermal requirements is interpreted as:

More insulation in the walls means pro-

portionally better energy-efficiency in the

building. Te reality is, the industry is do-

ing things wrong and as a result, bad deci-

sions are being made. Simply adding more

insulation to the walls will not necessarily

decrease the energy use of your building if

most of the heat flow bypasses the insula-

tion through poor details anyway. Tis will

leave you with diminishing returns as you

add more insulation.

As an analogy, the building envelope

can be thought of as a leaky water bucket

with several holes. You may keep trying to

plug one spot (for example, stuffing more

insulation into the walls) but the hole

right beside it is still leaking. If you want

to achieve real energy savings AND mini-

mize costs, you should consider the impactof these thermal bridges from transitional

components in our analysis (FIGURE 1

AND FIGURE 2).

Recent studies, such as ASHRAE 1365-

RP Termal Performance of Building

Envelope Details for Mid- and High-rise

Buildings, have shown that thermal bridges

in transitional components can be signifi-

cant contributors to heat flow through the

envelope and cannot be ignored. Te re-

sults show that lateral heat flow from studs

or other bridging elements in the wall as-

sembly connect to the bridging elementsof the transition components. Tis creates

3D heat flow paths that allow heat to by-

pass the insulation of high R-value walls

through the transition components, negat-

ing the benefits of having more insulation

in the walls.

Having common details, like exposed

slabs and metal flashings around win-

dows, can more than double the expected

heat flow. By ignoring these components,

the unaccounted for heat flow is passed

on as extra heating and cooling costs,

oversizing of mechanical equipment and

impacts on condensation and thermal

comfort that are not fully realized. Lets

also not forget about the cost of addingmore insulation.

Fortunately, there are sensible ways

to account for the effects of these thermal

bridges. Te method of linear transmit-

tance, as outlined in ASHRAE 1365-RP,

has been around for a while but not widely

used in North America. Now, with relevant

data to support the method, there is an op-

portunity to integrate this approach to im-

prove current practices.

Essentially, this method allows tran-

sitional details to be characterized by the

amount of extra heat flow they add to thewall assembly. For example, the linear

transmittance of a slab edge is the added

amount of heat flow from the slab per lin-

ear foot of the slab across the building.

Tis approach also works for point trans-

mittances, like steel canopy penetrations.

Thermal Bridging:

Ignorance is not BlissBy Mark Lawton and Neil Norris

Figure 1. Brick veneer assembly with flush

slab.

Figure 2. hermal profile showing heat flow

bypassing the insulation through the slab.


16/36


Tis allows details to be categorized from

poor to efficient in terms of the additional

heat flow they produce (examples for floor

slabs are shown inTABLE 1).

By characterizing the heat flow through

transitional details in this manner, design-

ers can more accurately make informed

decisions when designing energy-effi-

cient building envelopes. For example,the heat flow through a poor-performing

detail, like an exposed concrete slab edge,

could account for over 40 percent of the

heat flow through the building envelope.

Tis amount alone is surprising when

you consider that it is typically ignored in

calculations.

In comparison, a thermally efficient

detail, such as an insulated slab edge,

could contribute less than 10 percent. In-

sulating the slab edge could be much more

cost-effective than trying to add more in-sulation to a wall assembly. By addressing

transition components along with wall

and window assemblies, a designer can

more accurately evaluate what the best

way is to improve overall U-values.

In order to change current practice for

dealing with thermal bridging in transi-

tion components, communication be-

tween all members of the design team

is essential. Increasing the accuracy of

the U-values of walls will affect other as-

pects of the building design. Previously,

heating, ventilation and air conditioning(HVAC) equipment had to be oversized

with a significant safety factor because

thermal bridging was difficult to quantify.

Now, with the inclusion of an easy way

to determine this heat flow, HVAC load

calculations can be evaluated with more

confidence.

Moving forward, understanding and

integrating these thermal performance

methods into practice is required by all

parties involved in the building industry.

For the architect, this is identifying effi-

cient details over poor details in design.

For the HVAC engineer, this is under-

standing the impact of accurate wall U-

values on load calculations. For the energy

modeler, this is using overall U-values that

include thermal bridging in whole build-

ing energy simulations, as well as recog-

nizing the sensitivity of wall U-values on

simulated energy use. Most importantly,

for governing bodies and standards as-

sociations, this is acknowledging thermal

TABLE 1: SUMMARY OF FLOOR SLAB LINEAR TRANSMITTANCES

Floor Slab Detail Wall Assembly Linear ransmittance

Btu/hrft OF(W/m K)

Category

Exterior InsulatedZ-Girt Framing atConcrete Slab

Exterior Insulated SteelStud Wall

0.02 to 0.06(0.03 to 0.11)

Efficient

Insulated Metal

Panel at StructuralSteel Framed Floor

Horizontal InsulatedMetal Panel System 0.02 (0.03) Efficient

Exterior InsulatedZ-Girt Framing atStructural Steel

Framed Floor

Exterior Insulated andInterior Insulated Cavity

Steel Stud Wall

0.07 to 0.18(0.12 to 0.31)

Efficient toAverage

Termally Broken

Concrete SlabExtension

Exterior InsulatedBrick Veneer Wall with

Concrete Block Back-up0.12 (0.2) Efficient

Insulated MetalPanel at StructuralSteel Framed Floor

Vertical Insulated MetalPanel System with Metal

Stacked Joint0.19 (0.32) Average

Pre-Cast Concretewith Steel Anchorsat Concrete Slab

Sandwich Panel with no

Interior Insulation 0.12 (0.21) Efficient

Precast Concrete Panelwith ContinuousInterior Insulationbetween Panel and

Drywall Framing

0.22 (0.38) Average

Precast Concrete Panelwith Interior InsulationInterrupted by Steel Stud

Framing

0.29 (0.50) Poor

Stand-off Shelf

Angle Attached toConcrete Slab withContinuous MetalFlashing


Concrete Block Back-up

0.19 (0.33) Average

Exterior Insulated BrickVeneer Wall with Steel

Stud Back-up and CavityInsulation

0.18 (0.31) Average

Standard Shelf

Angle Attached toConcrete Slab withContinuous MetalFlashing

Exterior Insulated BrickVeneer Wall with Steel

Stud Back-up and CavityInsulation

0.26 (0.45) Poor


Concrete Block Back-up0.29 (0.51) Poor

Un-insulatedConcrete SlabExtension



Exterior Insulated SteelStud Wall

0.43 (0.75) Poor

Interior InsulatedConcrete Mass Wall

0.47 (0.81) Poor

Un-insulated

Concrete Slab withExterior Slab FaceFlush with Brick




17/36

Winter 2013 17

bridging and providing incentives for bet-

ter practice.

Tese governing bodies set the frame-

work for industry to find the most efficient

solutions. If thermal bridges in transition

components are not recognized by thecodes and standards, then there will not

be a level playing field for designers. Ac-

counting for heat flow through these tran-

sition components will make the building

appear to be worse off than if they were

just ignored. In reality, if the transition

components are recognized and ad-

dressed, the building will have a much

better thermal resistance. Tis creates a

bizarre situation where you are rewarded

for being less accurate. If there are no con-

sequences for bad practice, or no recog-

nition of good practice, then there is noincentive to improve on what is currently

being done.

If there are real gains of improving

overall building U-values to be made, then

the governing bodies and standards asso-

ciations will have to include accounting for

thermal bridging in transition components

in their compliance paths.

As architectural designs become more

complex and demands for energy-effi-

ciency increase, it will be up to industry

to ensure that current practice sufficiently

reflects reality. All members of the design

team must be aware of these issues to en-

sure thermal bridging is recognized when

it does make a difference. Otherwise, as

energy costs rise, the industry will find out

pretty quickly that ignorance is not bliss. n

Mark Lawton, B.A.Sc., P.Eng. and Neil

Norris, MASc., are with Morrison Hersh-

field, Ltd., based out of Vancouver, British

Columbia.

THERMAL BRIDGING ON CIRS

Te Centre for Interactive Research on Sustainabil-

ity (CIRS), located at the University of British Colum-

bia, is a good example of thermal bridging done right.

In fact, in order to achieve a high level of energy ef-

ficiency with the building envelope, thermal bridging

was minimized during the design of this building.

Te main structure is wood frame, using glulambeams and some concrete sections. Te cladding is

connected to the structure using intermittent clips, which significantly reduced the thermal bridging compared to continuous girts.

Tis also allows the exterior insulation to be run more continuously, especially over slab edges and rim joists. Te roof insulation is

run outboard of the structure with few penetrations. Additionally, the curtain wall was also aligned with the plane of the exterior

insulation to minimize heat loss at curtainwall transitions.


18/36


Feature

I IS A BEAUIFUL BUILDING. QUIE

stunning actually. It is an embodiment ofeverything that is right and wrong with archi-

tecture. An orgy of glass and concrete. It is a

thermodynamic obscenity while it takes your

breath away. An 82 story heat-exchanger in

the heart of Chicago (FIGURE 1, FIGURE 2

AND FIGURE 3).

Could it have been constructed different-

ly without the thermal bridges and without

changing the appearance? Sure. It could have

been an example of efficiency, not just iconic

architecture. And that would have been a

beautiful thing. And it could have been done

with off the shelf stuff, no less. How about atrue R-5 curtain wall between thermally bro-

ken cantilevered slabs? Check out FIGURE

4 and FIGURE 5. Tese are available right

here in the good ole US of A. Teyre alsoapparently available in Serbia (FIGURE 6)

and pretty much anywhere folks want them.

riple-glazed gas-filled curtain walls have

been around for a while. Te thermal breaks

have also been around for a while; mostly in

Europe and in Canada.

Te Aqua Building is not an exception.

Most buildings are like this; thermal bridges

galore. It is a big deal. Te good news is folks

are beginning to get it (ASHRAE 90.1) and

great work is being done on the research

side.1Te bad news is that although we know

this stuff, it is not getting used. It seems to methat folks are just not serious about energy.

Tis is an architectural problem. Tis is an

architectural detailing problem. Tis is an

architectural detailing problem that involvesstructural engineering. o deal with this is

going to require collaboration between ar-

chitects and structural engineers. Serious

collaboration.

oo often, structural decisions are made

in isolation from the energy impacts. It is not

that the structural engineer does not care. Its

just that no one asksbut its time to ask. Its

time to get great things from your structural

engineer.

Balconies are a big deal and everyone

knows that. But relieving angles can be an

even bigger deal. Tey go completely arounda building and sometimes occur at every

floor. Balconies rarely do, previous exception

noted. Te good news is that we know how

to deal with relieving angles. Te bad news is

that we often do not. Sound familiar?

Te best way to deal with relieving an-

gles is to hang them off of the building with

a stand-off (FIGURE 7)and then spread

them out every second or third floor. Tis

The Truth is

Out There:Efficiency and IconicArchitecture Can Co-ExistBy Joseph Lstiburek, PhD, P.Eng., ASHRAE Fellow

Figure 1. Extended finned-surface, made

of concrete. Figure 2. An infra-red of the Aqua ower.

DaveR

obleyandMichaelStuart,FlukeCorp.

Figure 3. An infra-red of an Aqua ower

balcony.


19/36

Winter 2013 19

allows your insulation to run past the angle.

Presto, continuous insulation (FIGURE 8).

Te stand-offs can be welded to plates cast

into slabs or welded to structural steel sup-

ports (FIGURE 9). Amazing as it seems to

civilians and other mere mortals, the archi-

tect obsesses over the location of the reliev-

ing angle. It cant be just anywhere. It has to

look good wherever it is. Sometimes it has toline up over the heads of windows for reasons

that escape me, a mere mortal, so we have to

ask the structural engineer to be clever (FIG-

URE 10). See, all you have to do is ask.

What if I do not like brick? Great, no reliev-

ing angles. How do I do panels? And, how do

I do panels conservatively if I dont buy into

all that other stuff you have talked about? Ok,

ok, ok. Check out FIGURE 11. Although the

structural design required for thin stainless

angles and long galvanized L-rails is simple,

engineers normally are designing for loads of

thousands of pounds (kips) and the hundred

pound loads involved here are unfamiliar

and sometimes scary.

We also have to deal with the thermal

bridges associated with windows. For rea-

sons that are unclear to me, where windows

are concerned, we dont call it a thermal

bridge, we call it flanking losses. Flankinglosses are losses around the window often

through the buck or through the structure

components the wall is installed in. Te bot-

tom line is that you need to line up the ther-

mal control layer in the window unit (a.k.a.

thermal break) with the continuous insu-

lation you are now required to install on the

exterior of the wall. Tat often means push-

ing your window outboard and hanging it in

mid-air, sort of. Gotta talk to the structural

engineer again. Magic will happen again.

FIGURE 12 has everything, including

relieving angles on stand-offs and bumped

out windows. Nice. I wonder if there are any

Leadership in Energy and Environmental

Design(LEED) points for this? Yeah, prob-

ably not.

Te best thing to do is to take your struc-

tural engineer out to lunch and discuss

relieving angles, window attachment andbalcony thermal breaks.

Enjoy a nice moment with your engi-

neer n

Joseph Lstiburek, PhD, P.Eng., ASHRAE

Fellow, is principal of Building Science

Corporation.

Unless otherwise noted, all photos/im-

ages provided by buildingscience.com.

Te rest of the images are located on the

next page.

Figure 6. he product shown here, which is being used on a

building in Serbia, prevents thermal bridges on balconies.

Beodom,Inc.,Belgrade,Serbia

Figure 5.Pre-manufactured thermal break. High-density graphite-

enhanced expanded polystyrene. Note the reinforcing rods

penetrating the foam are stainless steel, not carbon steel. Stainless

steel has less than half the thermal conductivity of carbon steel.

Figure 4.Section at balcony glazing interface. ake a high-

performance curtainwall and couple it with a high-density

expanded polystyrene thermal break and some basic slab water

control and you have a beautiful thing.

Figure 7.Relieving angles. Hang them off of the building with a

stand-off. his allows your insulation to run past the angle.

SchoeckCanada,

Inc.


20/36


Figure 12.A little bit of everythingrelieving angles on stand-offs

and bumped-out windows.

Figure 11. Clip and rail minimum thermal bridging to support

metal panels, fiber cement panels and composite panels.

Figure 10. Relieving angle line up. Notice how the relieving angle

lines up with the top of the window.

Figure 9. Stand-off. his can be welded to plates cast into slabs or

welded to structural.

Figure 8. Continuous insulation. If you are serious about energy,

this becomes standard practice.

MORE IMAGES RELATING TO THIS ARTICLE ARE AVAILABLE

AT WWW.BUILDINGSCIENCE.COM/DOCUMENTS/INSIGHTS/

BSI062-THERMAL-BRIDGES-REDUX

FOOTNOTE

1. ASHRAE Report No. 5085243.01, Termal Performance ofBuildingEnvelope Details for Mid- and High-Rise Buildings(1365-RP), addresses thermal bridges. Te report was doneJuly 2011, for echnical Committee 4.4, Building Materialsand Building Envelope Performance. www.morrisonhersh-field.com/.../MH_1365RP_Final_%20small.pdf.


21/36

Winter 2013 21

Principles - Devoted to Research; andPractices -Focusing on Practical Applications and Case Studies. Specifictopic workshops will be presented before and/or after the conference.

Inaugurated in 1979, the Buildings Conference takes place every three years allowing time to develop newresearch and technology applications and to document the findings. Attendance is international and draws heavilyon the advanced technical knowledge of all our global experts.

Te Buildings Conference presents a great opportunity for product manufacturers, research groups, technicaladvisors, builders, designers and other consultants to discuss their work achievements, interest and awareness ofbuildings issues, and provide solutions to some of our major building problems.

Tis is also a great opportunity to create a presence at the conference by becoming a sponsor. For additionalinformation on sponsorship, please contact Andre Desjarlais at [email protected] or phone (865-574-0022).

SAVE THE DATE!THE TWELFTH INTERNATIONAL CONFERENCE ON THERMALPERFORMANCE OF THE EXTERIOR ENVELOPES OF WHOLE BUILDINGS,SPONSORED BY BETEC, ASHRAE AND ORGANIZED BY THE OAK RIDGE

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2013 AT THE SHERATON SAND KEY RESORT IN CLEARWATER BEACH,

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TRACKS:


22/36

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January 6-10,

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And much more!Witness the Institutes impact on theindustry, interact with industry experinnovators, gain a wealth of informatthrough educational programs, earn share your expertise and experiencesparticipate in advancements toward better built environment.

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23/36

Winter 2013 23

Feature

MINIMIZING OUR USE OF ENERGY AND NAURAL RESOURCES

are vital components of the global strategy to protect our environ-ment and mitigate climate change. Buildings and the construction

sector represent a large portion of total global energy and resource

consumption. Te United States has responded to this awareness

with a tightening of building energy and performance standards.

ASHRAE 90.1 has significantly reduced the energy that can be con-

sumed by a building.

One significant aspect of energy loss from a building is conductive

heat transfer through the building envelope. Tere are common im-

provement strategies to minimize conductive heat loss that include

reducing the window-to-wall ratio, using high-performance window

systems and improving faade insulation. Tese assemblies are large-

ly responsible for the overall thermal performance of an exterior wall.Te focus has turned to a long-overlooked aspect of the design

thermal loss through structural components. raditionally, not a lot

of attention has been paid to the various thermal bridges that are in-

tegral to these larger envelope assemblies because they were thought

to represent a relatively small percentage of the overall energy loss.

As we improve the thermal performance of our overall wall systems,

however, the heat loss through thermal bridges becomes a much

greater percentage of energy loss and, thus, more important to con-

sider and control.

Tese overlooked thermal bridges are a concerning topic. Off-the-

shelf, manufactured structural thermal breaks (MSBs) have already

proven to be an attractive solution through their performance, not to

mention the material and system testing being completed by the sys-tem manufacturers. Tese products are now considered standard

building practice in Europe and are available in the United States mar-

ket now too.

IDENTIFYING STRUCTURAL THERMAL BRIDGES

Termal bridges are localized elements or assemblies that pen-

etrate insulated portions of the building envelope with thermally

conductive materials that results in high levels of heat loss. As a con-

sequence, in cold climates, low internal surface temperatures occurduring the winter that may create conditions for condensation and

mold growth.

In the case of uninsulated balcony slab connections, the interac-

tion of the physical geometry (cooling fin effect of the balcony slab)

and the material properties (thermal conductivity of a reinforced con-

crete slab) can result in significant heat loss, meaning that the unin-

sulated balcony connection is one of the most critical thermal bridges

in the building envelope (FIGURE 1). Buildings that contain uninsu-

lated balcony connections have significant incentives for adoption of

thermal break technology to improve thermal comfort, energy effi-

ciency and indoor air quality.

Generally speaking, there are many different structural elementsand/or building components that penetrate the building envelope

and may form thermal bridges. Tis includes balconies, canopies,

slab edges, parapets or corbels. Tese components are common ar-

chitectural features or essential structural elements in residential

buildings, as well as in commercial buildings, such as hotels, schools,

museums and gymnasiums.

Depending on the assembly design and climate zone, these struc-

tural penetrations through the buildings thermal layer are providing

a direct path for energy loss and premature structural damage due to

condensation. Another possible effect of thermal bridges includes an

uncomfortable living environment, due to differentiating tempera-

tures within one space. During the wintertime in a cold climate, the

center core temperature of the room needs to be increased to makethe edges and corners bearable. While some may think that radiant

flooring can combat thermal bridging, the result is an increase in en-

ergy use to constantly heat a lost cause.

AN APPROACH TO REDUCE THERMAL BRIDGES

Te more efficient a building is designed to perform, the more im-

pact thermal bridges have, as the thermal path will follow the easiest

route with the least thermal resistancestructural thermal bridges.

Thermal Bridging: The Final Frontierof High-Performance BuildingsBy Matt Capone, Assoc. AIA

Figure 1. his thermograph photograph shows that if thermal

bridges at balconies are not addressed, the balconies act as

cooling fins, conducting the heat off the building and cooling the

rooms adjacent to the balconies.

Figure 2. An illustration of balcony connections with structural

thermal breaks.


24/36


Windows are often seen as the largest thermal bridge in build-

ings because the thermal performance is often quite low compared

to the surrounding walls (for example, an R-2 metal frame window

within R-20 insulation). However, exposed slab edges and balconies

can have almost as large of an influence, having effective R-values

around R-1.

Tese weak links in the building envelope reduce the efforts of in-

sulation and air barriers. Te design team should be aware of the ther-

mal calculations of the design to ensure the entire building envelopemeets the projects expectations for efficiency.

o reduce structural thermal bridges, the engineer should also be

involved early in the design process. Architects deserve the freedom to

explore their design and working with the structural engineer earlier al-

lows time to find solutions to enhance or follow the design input. Tis

collaboration between the architect and engineer is essential to ener-

gy-efficient designs, especially when dealing with structural thermal

breaks.

SOLUTIONS TO STRUCTURAL THERMAL BRIDGES

Structural thermal breaks (FIGURE 2)reduce the heat flow, while

also conserving structural integrity. At uninsulated balconies, for ex-ample, the reinforced concrete at the connection is replaced with an

insulating material, while continuous reinforcement bars are used

to transfer loads (moment and shear). In some instances, these re-

inforcement bars may be replaced by stainless steel where they pen-

etrate the insulating material, as it is much less thermally conductive

than conventional reinforcing steel. Te use of stainless steel not only

reduces thermal conductivity but also guarantees longevity of the

structural components in the gap where no concrete protects them,

through its inherent corrosion resistance.

Other materials are also used in some proprietary systems, with

the aim of reducing thermal conductivity, such as concrete modules

to transfer compression instead of stainless steel.

Te combination of all these aspects means that structural ther-

mal breaks can average an equivalent thermal conductivity of k =

0.19 W/mK (0.110 btu/h ft K) to connect a standard balcony with a

cantilevered length of 2 m, instead of k = 2.2 W/mK (1.27 btu/h ft K)for reinforced concrete at an untreated balcony connection. Tis re-

duces the thermal conductivity at the connection by up to 90 percent

and can also elevate the surface temperature in the living area up to

a maximum of 63.7F (17.6C), depending on the nature of the struc-

ture.(FIGURE 3).

Te improvement in thermal performance by using MSBs may

benefit the application of green building programs, such as Leader-

ship in Energy and Environmental Design(LEED), by contributing

to the reduction in overall building energy use. ypically, a range of

MSBs are available from the manufacturer, depending on the load

requirements and deflection criteria, so that the optimal solution be-

tween structural and thermal performance can be found.

INTEGRATION IN BUILDING DESIGN

IN THE UNITED STATES

o ensure that the requirements of a project are met, an integrated

design process between the project architect, engineer, relevant spe-

cialty consultants, construction team and manufacturers technical

staff is recommended. For example, an appropriate design solution


25/36

Winter 2013 25

for a high-rise residential building with cantilevered concrete balco-

nies will vary based on regional construction practices and cladding

assemblies (brick veneer, architectural pre-cast concrete, exterior in-

sulation and finish system, painted concrete, etc.) (FIGURE 4).

Terefore, the project architect will be required to determine and

illustrate the location/placement of the thermal breaks, taking into

account considerations from the integrated design team. Tis will

include the code consultant to comply with code requirements for

fire resistance/protection specific to the project details; the building

envelope consultant to maintain continuity of the critical barriers (air,

moisture, vapor and thermal); and the structural engineer in order to

avoid interference with the structural attachment of other elements(glazing, framing, etc.).

Additionally, the structural engineer should also take into account:

slab rotation at the slab extension, primarily due to the elongation

of the unbonded bars in the MSB; expansion joints in the exterior

structure, due to thermal elongation of the exterior element; and

lap reinforcement to ensure the transmission of the loads into the

slab. Te manufacturers technical staff may also offer support with

those previously noted, based on project experience and research/

testing completed by individual manufacturers. Some manufactur-

ers provide recommendations for these considerations in their tech-

nical manuals, based on structural calculations for ensuring code

compliance.

o summarize, the following key points should be discussed

among the design team prior to the project architect illustrating the

integration of structural thermal breaks in design drawings:

Desired thermal performance;

Structural demand versus capacity of the MSB;

Minimum clearance required for structural attachment of other

elements;

Fire protection requirements at selected details;

Continuity of the building envelope critical barriers;

Waterproofing transition and connection details; and

Installation procedure and construction sequencing.

CONCLUSION

As energy efficiency requirements in the United States building

construction market continue to become more stringent, greater

emphasis and attention is likely to be required at thermal bridge lo-

cations in design. In addition to the energy use benefits of thermal

breaks, there are also other benefits, such as reduced risk of conden-

sation and mold occurrence and improved user thermal comfort.

Manufactured structural thermal breaks provide an attractive optionbecause the system testing has already been completed to facilitate

ease of adoption in design and construction.

Te integration and installation of MSBs has various consid-

erations that require collaboration among the project stakeholders

to ensure that the project requirements are met. Tis is no differ-

ent from any quality construction project. Adoption of this building

technology is growing and providing a knowledge base specific to

the United States construction market. Owners and developers can

also facilitate project specific adoption of this technology by utiliz-

ing design professionals and preferred product suppliers already

experienced with the integration of MSBs in building construction

in the United States. n

Matthew Capone, Assoc. AIA, is the United States Sales Man-

ager for Schck USA, Inc. Capone is an architectural designer with

a wealth of experience in design-build projects and implementing

energy-efficient strategies. His project experience extends from ini-

tial design development to construction practice. With a drive to cre-

ate a lasting positive impact on our communities and environment,

Capone applies techniques and industry insight to bring realization

to the table. He is both proficient in building information modeling

(BIM) and in energy-efficient strategies, such as Passive House. Ca-

pone holds a B.Arch. from Roger Williams University.

Figure 4. An illustration of a sample detail at a typical balcony with a

brick wall, for reference purposes. here are several solutions possible

and the shown detail should create an idea of how to integrate thermal

breaks in current construction methods. he shown waterstop should

solve the issue that the concrete curb is not integral with the slab.

Figure 3. he diagrams illustrate the influence of an effective insulation

product in a concrete construction. he heat can freely flow out via a

non-insulated balcony slab but by using the product, heat loss will be

reduced and the inside surface temperature will be increased.


26/36


27/36

Winter 2013 27

Industry Updates

NATIONAL

By Fiona Aldous, WJE; Building Enclosure

Council (BEC)-National Co-ChairTe BEC-National Executive Committee

is comprised of six members, including Co-

chairs Dave Altenhofen and Fiona Aldous;

Past-Chair Rob Kistler; AIA Liaison David

Herron; and Secretaries Whitney Okon and

Brian Stroik. In January 2013, Altenhofen will

transition to the role of past-chair, Aldous will

take on the position of chair and a new vice

chair and secretary will be selected.

BEC-National is responsible for organiz-

ing, assisting, supporting and promoting the

individual BECs in their local efforts; address-ing issues at a national level that are common

to some or all of the BECs [such as recent

code hearings regarding the use of plastic in-

sulation and compliance with National Fire

Protection Association (NFPA) 285]; the pro-

motion and encouragement of discussion,

training, education, technology transfer, ex-

change of information about local issues and

cases, relevant weather conditions, and all

matters concerning building enclosures and

the related science; and dissemination of best

practice knowledge to all concerned with the

building enclosure.BEC-National has assisted in the devel-

opment of the recently-formed BEC-Cleve-

land and is currently coordinating with an

additional three cities interested in joining

the growing list of BEC chapters around the

country. We look forward to 2013 as an excit-

ing year for BECs.

AUSTIN

By Keith A. Simon, AIA, LEED-AP, Associate

III, WJE; BEC-Austin Chair

BEC-Austin programming for 2012 con-

sisted of Daylighting Fundamentals, by Keith

Simon, WJE, in January; a Spray-Foam Round-

table in February; Vapor & Te Building Enve-

lope Basics, by Jen Doyle, Engineered Exteriors,

in March; Sustainable Green Roofs for exas, by

Bruce Dvorak, exas A&M, in April; Commer-

cial Roofing Fundamentals, by Dennis Wilson,

C-CAP, in May;Advanced Roofing Seminar, by

Edis Oliver, WJE, in June; Building Enclosure

Fundamentals, by Matt Carlton, WJE, also in

June; a High-Performance Detailing Symposium,

by Brian Roeder, PSP and Will Wood, McKin-

ney/York, in July; Termal Imaging & Building

Diagnostics,byJames Kolarik, Entest, in August;a Construction Litigation Roundtable in Sep-

tember; Sealants 101, by Ben Rogers, remco,

in October; and Integrated Enclosure Design, by

Justin Wilson, Building Performance Solutions,

in November. In December, we were excited to

host our first full-day seminar, Adventures in

Building Science, with Joe Lstiburek, Building

Science Corporation.

Another new initiative for BEC-Austin in

2012 was the formation of the International

Energy Conservation Code (IECC) task force,

led by Jeff Acton, WJE & Scott Magic, MichaelHsu Office of Architecture. We provided com-

ments and recommendations on the enclo-

sure items in the 2012 Energy Code for the

city of Austin through open forums with the

Austin-AIA.

In 2013, erese Ferguson, DFP, will be the

primary BEC-Austin chair; Keith Simon, WJE,

will remain as co-chair; and John Posenecker,

Chamberlin, will also join as co-chair.

BOSTON

By Jonathan Baron, AIA, LEED-AP, Associate,

Shepley Bulfinch; Boston-BEC Co-ChairTe Boston-BEC continues to meet

monthly (except for August and Decem-

ber) at the Boston Society of Architects new

headquarters in downtown Boston. Recent

presentations have included How to Avoid

Wall Flashing Leaks, by BEC-Boston mem-

bers Matthew Carlton and Derek McCowan,

Simpson Gumpertz & Heger; Durability

Analysis for Building Envelopes by Achilles

Karagiozis, Owens Corning; andA Compari-

son of Original and Replacement Windows,

by BEC-Boston member Jarod Galvin, Frank

Shirley Architects. We typically have 30 at-

tendees at our meetings and there is always

spirited discussion with the presenters.

In addition to presentations, BEC-Boston

held a detailed workshop in October, at which

five groups analyzed details and presented

findings to the larger group. Each team traced

thermal barriers, air barriers, vapor retard-

ers and drainage planes and described in-

congruities and potential improvements.

While we usually host great discussions, this

exercise led to exceptional involvement from

all members present.

Founding chairperson Richard Keleher,after serving as co-chair since the founding

of the first BEC in 1996, has stepped down.

Maria Mulligan, past co-chair, has accepted

the position again and will lead with current

Co-Chair Jonathan Baron. We thank Richard

for his 16 years leading the BEC and establish-

ing the template for BEC chapters around the

country.

Visit us at www.bec-boston.org.

CHICAGO

By Kevin A. Kalata, RA, SE, AssociatePrincipal, WJE; BEC-Chicago Co-Chair

BEC-Chicagos membership continues

to grow. In 2012 alone, we have added more

than 60 new members, raising our total

membership to over 180. Our success can

be attributed to the quality of our monthly

presentations. BEC-Chicago is committed to

providing high-level technical presentations

related to current topics affecting the design

and construction of enclosure systems. Re-

cent presentation topics have covered solar

reflectivity, by Curtainwall Design Consult-

ing; high-performance faade technologies,by Goettsch Partners; vacuum-insulated

panels, by Larry Carbary, Dow Corning; and

stone faades, by Chuck Muehlbauer, Marble

Institute of America.

Our website (www.bec-chicago.org) was

revamped and re-launched earlier this year.

It is based on an interactive platform that al-

lows users to create and update their profiles

and access contact information for other

members, as well as view and post upcoming

events. Te site also serves as a resource for

building enclosure documents and links.

In 2013, BEC-Chicago is looking to build

upon this platform to provide additional

features, including a technical forum where

BEC members can post and/or reply to in-

quiries, automated RSVPs for our monthly

meetings and web-based elections. Funding

has been provided by our generous spon-

sors and we would like to thank them for

their continued support: Corinthian-level

BAMR; BASF; Certaineed; Grace; Henry;

Raths, Raths & Johnson; Sto; USG; and WJE.

BEC Corner


28/36


Doric-levelDow Corning and Powers

Fasteners.

For more information: [email protected],

[email protected] or [email protected].

CLEVELAND

By Nate Gamber, PE, WJE, and Ed aylor,

echnical Assurance, Inc.; BEC-Cleveland

Co-ChairsSince our formation last spring, BEC-

Cleveland has been met with enthusiasm

and support from AIA-Cleveland and the lo-

cal building community. Following a charter

sponsor drive that was conducted throughout

the summer, BEC-Cleveland kicked off our

inaugural technical presentation on October

17, 2012. We were thrilled and gratified with

the support provided to BEC-Cleveland by all

of our charter sponsors and we doubled our

initial goals heading into the charter sponsor

drive. Nearly 150 professionals attended ourkick-off meeting, which featured a presenta-

tion by keynote speaker Dr. Joseph Lstiburek,

Principal of Building Science Corporation.

Dr. Lstiburek charmed the audience and gave

an insightful, educational and entertaining

presentation on building science topics, sus-

tainability and how these issues specifically

relate to the climatic conditions of Northeast

Ohio. Several architecture students from Kent

State University were in attendance as well.

On December 5, 2012, erry Brennan,

chair of the Air Barrier Association of Amer-

icas Whole Building est Committee, provid-ed an overview of air barriers. opics covered

included performance requirements of air

barrier materials, assemblies and systems,

common design and installation issues, code

requirements and market forces driving en-

ergy-efficient buildings. Future presentations

are anticipated to cover NFPA 285 and build-

ing enclosure commissioning topics.

On behalf of BEC-Cleveland, wed like

to thank AIA-Cleveland and our leadership

board for all their hard work in starting our

chapter and coordinating our first technical

presentations. Wed also like to thank and

recognize our charter sponsors. Without their

generous support we would not be able to

provide these programs:

Platinum: Johns Manville (REPSof-

OHIO); DuPont yvek (Parksite); Dow

Corning; remco; VIP Restoration; and

WJE.

Gold: Firestone Building Products (Ad-

vanced Building Products); Derbigum;

Prosoco; and echnical Assurance, Inc.

Silver: Siplast (Icopal); SikaSmart (ChilCo

Diversified); Mid State Restoration, Inc.;

ECO Commissions; Integrated Engineer-

ing Consultants, Inc.; and Chas. E. Phipps

Co.

Annual: Propertiesmagazine.

Visit us at www.bec-cleveland.org.

COLORADO

By Linda McGowan, PE, AIA, Building

Consultants & Engineers, Inc.; BEC-Colorado

Past Chair

In its eighth year, BEC-Colorado (BEC-

CO) continues to maintain a strong presence,

with monthly programs preceded by a brief

business meeting averaging 43 attendees

who have backgrounds in architecture, engi-

neering and construction. BEC-CO is grateful

to JE Dunn for the use of their Denver confer-

ence room.

In 2012, BEC-CO program topics includ-ed: January, Designing with Spray Foam In-

sulation; February, Ensuring Compliance of

Fenestration with odays Energy Codes and

Green Standards; March, Electronically int-

able Glass: A Project Showcase; Apri, Polyiso:

Te High-Performance Choice for Continu-

ous Insulation; May, Precast Concrete Sand-

wich Wall Panels; June, Building Envelope

Construction Defects; July, Skin and Bones:

Breaking Structural Faade Design Down to

Its Essence;August,Attaching Exterior Veneers

Over Continuous Insulation; September,

Annual Fall Seminar, Why Buildings Mat-ter - Sustainability Challenges and Building

Science Lessons; October, Annual planning

meeting; November,Building Envelope Com-

missioning; and December,Air/Water Barrier

Detailing.

At our annual fall seminar, Chris Mathis

entertained a crowd of more than 110 at-

tendees, with a focus on building energy con-

sumption during construction and over the

potential 100-year life of a building. He also

provided a thought-provoking analysis of the

myriad of factors associated with building de-

sign and construction.

Te success of the BEC-COs annual fall

seminar is due in large part to the support of

our sponsors: Colorado Prestressers Associa-

tion; HDR Architecture; SBSA, Inc.; American

Hydrotech; BASF; BMC & Anderson Win-

dows; Building Consultants & Engineers.;

CAD-1; Carlisle Coatings & Waterproofing;

CENRIA Architectural Systems; Cosella-

Dorken Products; Dow Building Solutions;

Georgia-Pacific; Group 14 Engineering; Nagel

& Associates, RW Specialties; VaproShield

by Elliott Associates; W.R. Grace; and CWA

Architecture.

BEC-CO leadership consisted of Chair

Chip Weincek, AIA, LEED-AP; Programs Di-

rector David Milliken, AIA; and Secretary Will

Babbington, AIA, PE, LEED-AP. As of October

2012, new positions are: Chair David Millik-

en; Programs Director Will Babbington; Sec-retary Alastair Huber, AIA; Communications

Coordinator John Price; and Sponsorship

Coordinator Jim Holt. BEC-CO is thankful for

the support of the AIA-Colorado and the tre-

mendous efforts of Jenna Cather.

For 2013, BEC-CO will continue to explore

diverse program topics including the seventh

annual BEC-CO Fall seminar in September

2013. BEC-CO plans to support the AIA-BEC

and BEEC by funding the Chair to represent

BEC-CO at a national BEC conference.

DALLAS

By Dudley McFarquhar, PhD, PE,

McFarquhar Group, Inc.; Dallas-BEC Chair

We are excited to report that the 2012

lectures series, Dynamic Dallas: Innova-

tive Building Enclosure Design,was a suc-

cess and sparked growth to our chapter.

Our monthly series began with the Perot

Museum of Nature and Science, with a talk

by the design team of Morphosis (CA) and

continued to lively events on the building

enclosures of the Winspear Opera House

(McFarquhar Group Inc and Seele, Inc.);the retractable roof of the Cowboys Sta-

dium (HKS and K Post); and the innovative

tubing cladding system of the Wyly Teatre

(McCarthy). Before our summer break, we

held a highly-attended meeting on the new

International Building Code(IBC) 2012 re-

quirements for NFPA 285 testing (Carlisle).

Stepping back into the groove after our

summer hiatus, Septembers gathering was

done exas style with a barbeque meet and

greet and open discussion on trends, chal-

lenges and recent experiences regarding

building enclosures. We have had regular

meeting attendances averaging 40 people

with 75 maximum to date.

In October, we focused on how software

is integrated to assist in helping design a

better performing building. Representatives

from WJE and Corgan Associates presented

Dynamic Design ools Used with Buildings &

the Building Enclosure: WUFI and BIM. We

closed out the year with a coda to our Dy-

namic Dallas series and a presentation on


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Winter 2013 29

the Dallas Audubon Center with BRW. Tey

discussed their design concept for the first

LEED-certified Dallas Park and Recreation

Department project.

We are thrilled looking to 2013, with a

presentation in the works focusing on the

adoption of the International Green Construc-

tion Code (IgCC) in Dallas. o learn more,contact me at [email protected] or followus on LinkedIn: Building Enclosure Council

Dallas.

GREATER DETROIT

By Brian J. ognetti, RA, CCCA; BEC-Greater

Detroit Program Committee

In 2012, BEC-Greater Detroit (BEC-GD)

again offered multiple engaging technical

seminars. Annually, we provide six regular-

ly-scheduled, one-hour presentations on

cutting-edge building science, focusing on

guidance for building owners, facility man-agers, design professionals, construction

managers, contractors, material suppliers/

fabricators and other interested parties. We

averaged nearly 60 attendees per hourly pro-

gram, and when considering the October

Annual Symposium, with over 200 registered

participants, the BEC-GD has provided con-

tinuing education with an overall contact

hour-to-date tally exceeding 5,000 hours!

On October 16, 2012, the BEC-GD host-

ed its 4th Annual Symposium in Livonia,

Michigan. Te attendees benefitted from a

distinguished panel of nationally recognizedexperts in the field of building enclosures.

Tis years symposium, rends in Building

Enclosure Performance, was presented by

Henry Green, President of the National Insti-

tute of Building Sciences; Fiona Aldous, Asso-

ciate Principal with WJE; Dr. Teresa Weston,

Research Fellow with DuPont Building Inno-

vations; and Christopher Mathis, President of

MC2 Mathis Consulting Company. As with

our past symposiums, the cost to attend was

less than $10 per credit hour, an exceptional

value considering the technical topics and

networking opportunity.

Te BEC-GD also took the opportunity

at the symposium to present a plaque to the

outgoing chairman, Steve Robbins, thank-

ing him for his commitment, dedication and

leadership to BEC-GD.

For additional information, please con-

tact any of our board members by visiting the

AIA-Detroit website (www.aiadetroit.com)

and clicking on the committee link to the

BEC Building Enclosure Council Committee.

For specific program information, contact

Andrew Dunlap (313-442-8186 or andrew.

[email protected]). For program

sponsorship opportunities, contact Dan

Zechmeister (248-663-0415 or dan@mim-

online.org).

MINNESOTA

By Judd Peterson, AIA, Chair, BEC-MinnesotaFollowing is a synopsis of what happened

in 2012. BEC-Minnesota participants Al Ger-

hke and Dick Quandt presented a two-part

session about Rockwool acoustic and fire

safing insulation. Ten Craig Wetmore, York

Manufacturing, made a visit to explain Yorks

decision to discontinue their fiberglass-clad

copper flashings in lieu of an elastomeric-

coated copper flashing.

James Reed, Termocromex, came to ex-

plain the versatile, limestone-based, exterior

finish coating. And for the high-tech, future-

is-now people, we had Paul Wisniewski, Dow

Corning, come to talk about Dow Corningsnew vacuum-insulated panels. Tese are the

panel materials that have extraordinary R-val-

ues of 25 to 30 per inch! We also participated

in a Dow webinar about NFPA 285 and spray

foam assemblies.


30/36


im Eian and his associates, Peter Yackel

and Jay Weiderholt, invited us to participate

in further discussions about passive house

energy-efficient construction. We joined

them for a discussion about the design and

construction on the MinnePHit House, which

was a significant retrofit effort.

Retrofitting for energy efficiency has be-

come urgent and, in response, MinnesotaSenator Al Franken has developed the Back

to Work Minnesota: A Retrofit Jobs Initiative.Senator Franken participates as co-chair of

the National Institute of Building Sciences

Senate Caucus on High Performance Build-

ings and he and his staff are currently work-

ing with Institute president, Henry Green, to

develop this retrofit program.

Working with the BEEC Board Com-

mittee on Education Curriculum for Build-

ing Commissioning Certification, our BEC

participants have volunteered with variousMinnesota state colleges and universities,

primarily including Inver Hills Community

College, in developing curriculum with the

Institute for this Commissioning Certification

through the alliance between the Institute

and ASM.

o this end, Senator Frankens staff, in-

cluding Lisbeth Kaufman and Katherine

Blauvelt, worked with Deanna Christensen

and Beverly Hauschild of AIA-Minnesota,

Rick Carter of LHB, and with BEC-Minnesota

to present an update on the status of the ini-

tiative, the BECx curriculum and the retrofitinitiative at the AIA-Minnesota Annual Con-

vention in November.

PHILADELPHIA

By Cheryl Smith, AIA, LEED-AP, Cope Linder

Architects and Joe DeAngelis, AIA, LEED-AP,

BS Services; BEC-Philly Co-Chairs

BEC-Philly membership continues

to grow; we now have almost 300 on our

contact list. Attendance at monthly meet-

ings averages about 50. Te meetings are

free and held at AIA-Philadelphias Center

For Architecture over lunch and include a

one-hour technical presentation focused

on building enclosures and related building

performance issues.

BEC-Philly is excited to host a round-

table discussion with the German Fed-eral Ministry of Economic and echnology

and the German American Chamber of

Commerce, Inc. Te topic, Integrating

High-Performance Products into a Whole-

Building Design, will be moderated by

David Altenhofen, Te Faade Group. Te

morning session will explore issues re-

lated to incorporating high-performance

attributes into projects and to share the

different experiences between Philadel-

phians and Germans as they create en-

ergy-efficient buildings. Te round tablewill explore ideas for the evaluation of

products and materials in a holistic fash-

ion that makes their performance a crucial

value-added part of the whole building.

We wish to thank the Architectural Glass

Institute for their generosity in support of

this event.

We were fortunate to have the opportu-

nity to host Herb Yudenfriend this summer

and wish to thank him for making a presenta-

tion regarding security glazing. We especially

thank Valerie Block, DuPont, for her extreme-

ly interesting and impromptu presentationon laminated glass. We are most grateful for

Valeries knowledge and support!

RESEARCH TRIANGLE

By Rita Ray, Senior Associate, WJE; BEC-R

Chair

Since our founding in May 2011, the Re-

search riangle (BEC-R) continues to have

regular involvement from local industry

representatives and our membership has

grown to over 200. Te BEC-R board used

their free time over the 2012 summer

monthly meeting break to develop and pub-

lish the new group website, which can be

found at www.bec-researchtriangle.org. It

is organized to provide visitors with general

information about us, upcoming BEC-R

events, sponsorship, relevant educational ref-erences and upcoming national events that

are of interest to our members.

Trough the course of 2012, the chapter

hosted regular monthly meetings with pre-

sentations by J. Patrick Rand, NC State Uni-

versity, Comparison of Masonry and Other

Cladding Materials in erms of Embodied

Energy and Carbon Dioxide Costs; Mike

Gainey, Azon USA Inc., Optimizing Perfor-

mance in Commercial Fenestration; Keith

Boyer, Centria, Navigating High-Performance

Wall Systems Using Insulated Metal Panelsand Integrated Windows; Bill Warren, South-

ern Energy Management, Energy-Efficient

Commercial Buildings Trough Air Barrier

Consulting and esting; Larry Harmon, Air

Barrier Solutions, LLC, Finding Air Leakage

in Small and Mixed Use Commercial Building

Enclosures; Brian Cordak, Koster American,

Solutions for Floor Moisture Control; Scott

LaPorte, BBH Design, Moisture Migration:

Hygrothermal Analysis of Complicated Wall

Sections; Kevin Day, Freelon Group, Docu-

mentation of Complex Building Enclosures;

and Andrea Wagner, Dow Corning Corp.,Sealants in Air Barrier Systems. BEC-R also

hosted a full-day roofing seminar in May,

with technical presentations by design and

manufacturer experts.

Many thanks again to our chapters found-

ing sponsors: Baker, BBH Design, Centria

Architectural Systems, CFE Roofing, Curtis

Construction Co., Custom Brick and Supply

Company, Dow & Knight Wall Systems, Te

Freelon Group, Hydrotech, Lend Lease,

Perkins+Will, VMZinc and WJE. Tanks also

to our 2012 monthly and event sponsors:

Carlisle Coatings & Waterproofing, Custom

Window Company, Centria Architectural

Systems, Grace Construction Products, Fiber-

tite, Permier Building Products, Sika/Sarnafil,

remco, Inc., Koster Waterproofing Systems,

David Allen Company/Supercap LLC, Cus-

tom Brick and Supply Com

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