Construction green breakfast - you don't have to be a hippy to build with hemp!

You don’t have to be a hippy

to build with hemp! Ian Pritchett

Contents

• Overview of Lime Technology Group

• Background to Tradical® Hemcrete®

• Hemclad® & Hembuild®

• Thermal performance

• Unique funding model

Questions

• Which is lower cost?

– £5,000

– £100 per week

• What is the difference between cost and

value?

• What make people choose – cost or value?

• Who drives a BMW?

24 February 2013 3 www.limetechnology.co.uk

Lime Technology Group

• Lime Technology Ltd. - manufacturers and

suppliers of breathable construction products:

– Lime mortars, plasters & renders

– Insulation products

• Hemp Technology Ltd. – largest hemp

processing factory in Europe

• Hemcrete Projects Ltd. – specialist “design &

build” sub-contractor

Joseph Chamberlain College

Limetec® Mortar

CTRL Terminal, St Pancras

Limetec® Mortar

7

Industrial Hemp

Fibre

s Shiv or Hurd

Seed

Hemp Harvesting in UK

Hemp Drying

Hemp Baling

Hemp Processing (Suffolk)

Fuel Briquettes (from waste)

Breathe® Insulation (from fibre)

•

BMW – Door Panels (from fibre)

Lotus Eco-Elise body shell

(from fibre)

Hemp Shiv (woody core of stem)

Tradical® Hemp Binder (HB)

Production (Oxfordshire)

Tradical® Hemcrete®

New Technology

From Hemcrete® to Hembuild®

• Traditionally Tradical® Hemcrete® was cast or

sprayed in a wet site process

– 6 to 8 week drying period (in good conditions)

– Best suited to use between March and July

• Now you can get all the benefits of Tradical®

Hemcrete® in an off-site panelised system that is

dried before it gets to site

– Hemclad® and Hembuild® panels

– No seasonal/weather restrictions

Hembuild®

U-values & Y-values

• 5 standard U-values

– 0.19 W/m2.K

– 0.17 W/m2.K

– 0.15 W/m2.K

– 0.13 W/m2.K

– 0.11 W/m2.K

Excellent Y-values

Typically 0.02 to 0.04

Benefits

• Grown and manufactured locally

• From renewable/abundant sources

• Lock up carbon

• Thermal stability from insulation and

thermal inertia

• Fire resistance

• Warranties and accreditations

Embodied Carbon

-40

-20

0

20

40

60

80

100

Embodied

Carbon

Cavity wall

Clay block

Hemcrete

Affordable Housing

Private Houses

Hemcrete® Buildings

Hembuild® & Hemclad®

• Bespoke Panels

• Designed to fit your building

• Designed by our engineers – To accommodate vertical loads

– To accommodate wind loads • In plane (racking)

• Out of plane (bending)

• Can be used with primary structural frame – Hemclad®

• Can be used without a primary frame for low rise buildings – Hembuild®

Hemclad® - M&S Cheshire Oaks

• 4 year lead in

• Design support to client team

• Manufacture of 2600m2 of Hemclad®

panels

• Site erection of Hemclad® panels

• 100% FSC chain of custody

• U-value of 0.12W/m2.K

Hemclad® - M&S Cheshire Oaks

Hembuild® - Passiv Haus

• Brick (& lime mortar) faced private house

• Passive Haus specification

• U-values

– Walls – 0.11W/m2.K

– Roof – 0.1 W/m2.K

– Minimal thermal bridging

• Air-tightness – 0.6 air changes per hour

• Built using Hembuild® system

Hembuild® - Passiv Haus

30 year costs

60 year costs

Hempod- 200mm thick walls

Standard Cast

on-site Wall

System

Thermal damping

~80% for 200mm thickness

Humidity control

~95% for 200mm thickness

Science Museum Archive

• Putting theory into practice

– Based on Bath University test data

• 10,000 Sq ft, 3-storey archive

– Sits within a WWII concrete aircraft hangar

– Steel frame (10KN floor loading)

– CLT floors (160mm & 100mm roof slab)

– Hemclad® walls (200mm)

– 40mm wood fibre board cladding

• Using the Hemcrete® to passively control temperature & humidity

Cast panels – 200mm thick

The hangar

Cross Section

Completed Archive

Photo courtesy of Jennie Hills/Science Museum, London

Thermal modelling

• Used external measured weather data from the site and the building geometry to create an IES simulation of the Hempod

• Ran IES model of the SIMULATED performance of the Hempod

• Exported results into a Fourier format

• In parallel we created a Fourier model of MEASURED internal temperatures in Hempod (test building)

Thermal modelling

Thermal modelling

• Created a mathematical relationship between Fourier models of IES SIMULATED and MEASURED internal temperatures in the Hempod and obtained a Fourier “filter”

• Built and run IES model of the Science Museum Archive

• Applied the (same) Fourier filter to the internal temperatures obtained from IES SIMULATION to obtain best PREDICTED performance

Fourier filter applied to IES simulated temperature (by Dr L. Jankovic, Emission Zero R&D)

Fourier filter applied to IES simulated relative humidity (by Dr L. Jankovic, Emission Zero R&D)

M&E System Spec.

• Air handling unit system reduced from

30KW to 5KW peak load

• 2KW average load

• Power from PV array

• M&E cost reduced by 75%

• Reduced on-going maintenance costs

• Cheaper than a block-work archive!

On-going Monitoring

Thermal Performance

• Tradical® Hemcrete® exhibits a dynamic

thermal performance that greatly exceeds

that predicted in conventional thermal

modelling software (IES)

• Quantifying this performance shows that it

is a cost effective building material

• This is currently an experimental

approach, but it is backed up by real

monitoring data on nearly 40 buildings

Future Thermal Modelling

Cost Efficiency

• Modelling shows heating system can be

reduced from 17KW to 4KW (peak)

• Saving on heating system off-sets the

extra cost of the Hembuild® walls

• Cost neutral on construction

– Lower running costs

– Lower maintenance costs

– Lower CO2 emissions

• True sustainability!

A Unique Team

• Lime Technology Group

• Amalgamated Capital

• Mark Hines Architects

• The Green Organisation

What we offer…

• Fully funded projects

– 30 year commercial bonds

– Retention of appreciating assets

• Innovative building system – Hembuild®

– Exemplary thermal performance

– Local manufacture & local jobs

– Natural materials - hemp & timber

• Contemporary design & master-planning

AmCap USP’s

• Bond is provided up-front to finance the delivery

of the whole project

• Bond is based on income potential of the houses

• Bond interest rolled up during construction

period

• Debt sits off the RP’s balance sheet

• Asset reverts back to RP after 30 years

• The ideal balance between ease, cost and

value!

Summary

• Fully funded projects

– 30 year commercial bonds

– Retention of appreciating assets

• Local manufacture

– Local jobs

– Natural materials - hemp & timber

• Contemporary design & master-planning

• Exemplary thermal performance

The best way to

predict the future

is to create it

Construction green breakfast - you don't have to be a hippy to build with hemp!

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