Post on 13-May-2015
description
End Use of
Sustainable Buildings
Lessons Learnt
13th November 2013
1. An introduction to sustainable buildings
2. The challenges to achieving them in reality
3. Post occupancy evaluation of sustainable buildings
4. Case study of the Marks & Spencer Sustainable Learning Store
5. Questions and answers
Agenda
Impacts of the built environment
• The construction and maintenance of buildings is responsible
for around half of UK carbon dioxide emissions.
• The construction industry consumes around 6 tonnes of
materials per year for every person living in the UK
• More than 400 million tonnes of materials get delivered to site
each year. Of these 60 million tonnes go straight to tip.
Regulatory and other drivers
• Revisions of Part L of the Building Regulations
• EU Energy Performance of Buildings Directive
• DEC’s and EPC’s
• Code for Sustainable Home
• Tax incentives
• Zero Carbon Targets
• 2016 for homes
• 2019 for non-domestic buildings
Recent Sustainable Buildings
Co-op Headquarters World Wildlife Fund Headquarters
The Performance Gap
Most sustainable buildings do not perform as
well as the initial design claim
After a year of operation, London City Hall was consuming a reported 50% more energy than it had been predicted to consume
Pre-Occupancy Measures
• BIM and Soft Landings
• BREEAM
Pro
ject
tea
m e
ffo
rt
Briefing
Stage B
Design
Development
Stage D
Pre-
Handover
Stage P
Initial
Aftercare
Stage A
Years 1 to 3
Extended Aftercare
Stage Y
• Technique for understanding how buildings are performing
• Includes monitoring of performance and occupant satisfaction
• Energy, carbon, waste, water, satisfaction, productivity
What is Post Occupancy Evaluation?
• Understand the gap between design and actual performance
• Understand the importance of occupant engagement
• Save money
• Put greater onus on the design team / contractor
• Test if renewables worked
Why use it?
Productivity gains
Marks & Spencer Cheshire Oaks Eco Learning Store
Located in the Cheshire Oaks Retail Park near
Ellesmere Port
Gross internal area: 19,500 m² Net sales area: 13,800 m²
Covering two floors Complete with three cafes and a
extensive food hall
Plan A aspirations: Reduce the impact of M&S buildings
on the environment and become come more resource efficient
Building features
• The roof is made of FSC-certified glulam timber.
• 230 prefabricated Hemclad® panels have been
used in the wall delivering a design U value of
0.12.
• Aluminium “white” roof reflects excess heat.
• North lights in the roof to maximise the use of
natural light
• High level of air tightness <3m³/hr.m² @ 50 Pa
Low Carbon Building Services
• 300 kW wood pellet boiler
• Displacement ventilation system with six
independently controllable zones and free cooling
• Automatic light dimming system to utilise daylight
where available
• CO2 refrigeration system with CO2
piped directly to food cabinets and
cold rooms.
• Heat reclaim on the refrigerators.
• 80,000 litre rainwater harvesting
system predicted to reduce mains
water consumption by 25%
Biodiversity
• 300 m² living wall with 30 plant species.
• The retention of a swale area and pond
• 228 new trees
• 9 swift boxes have been built into the wall at concealed location for mating swifts to use.
• A further 6 bird boxes in the perimeter fence
• Wildflower meadow bank around edge of the store
Staff and customer enhancements
• Transport enhancements
o Improvements to cycle ways, crossings, roadway and
footpaths
o Contribution towards improved bus services
o Electric car charging points
o Staff shower and cycle stands to encourage cycling
• 400 new jobs
• Educational visits to schools and universities
• Interactive information points throughout the store
Planned activities
Overview of POE Tasks • 1 year’s worth performance monitoring
• Assess building envelope
• Benchmark against other buildings in the M&S portfolio
• Assess the sustainable features
• Survey staff and customers
• Review biodiversity
• Disseminate the good practice lessons
Questions the POE aims to answer
• Which features work, and which do not?
• Is the extra effort involved in providing these features worth the effort?
• Are operational costs reduced? – Initial signs are promising as we will see.
• Do the store’s features attract more customers and generate more sales?
• What are the key lessons to be carried over to future developments?
Performance Targets for the Store
Design and construction data
• To fully understand the post occupancy performance of a building, an understanding is required of the events leading up to it being put into use.
• Design documents provide the basis of understanding how the building was originally intended to operate.
• Issues arising during construction can cause the design of a building to be altered away from the original intent.
• Issues arising during the operational phase
can sometimes trace their roots back to
issues at the design, construction or
commissioning phase.
Measuring Energy Performance
Building management system
Monthly energy reporting
Sample monthly energy report
Lighting – Electricity use carpet plot
Days over the monitoring period
Ho
urs
of
the
day
Good at switching off outside trading hours.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
1:00
2:00
3:00
4:00
5:00
6:00
7:00
8:00
9:00
10:00
11:00
12:00
13:00
14:00
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19:00
20:00
21:00
22:00
23:00
0:00
Building Fabric Performance
Contractor’s survey focused on integrity of the insulation
F+G’s survey focused on the building’s heat
loss
Building fabric performance
External temperatures less then 0°C
Thermal imaging surveys cannot verify air tightness of a building and therefore other methods are required.
21.30°C
20.65°C
23:00 07:00
Biodiversity findings
• Sources of information include:
Pre-construction habitat survey
Post-construction habitat survey
BREEAM retail assessment
Site biodiversity meeting
• A site biodiversity action plan has be
produced. The plan has 9 site specific
targets which are all on track to be
achieved - examples:
No loss of amphibian breeding,
foraging and shelter habitat.
Retain and protect hedgerows
where practicable
Results
Electricity performance against benchmarks
Staff Survey
Lessons learnt from Cheshire Oak
Key factors that contribute to the successful operation of the building:
• Clear vision for the building expressed through Plan A and the
Sustainable Construction Manual.
• Close collaboration with designers and contractors throughout the
construction and commissioning process.
• Detailed hand-over process with clear operation and maintenance
manuals.
• Post occupancy workshops which bring together designers, contractors
and facilities staff to examine the building’s performance in use.
Lessons learnt continued
The fundamental principles of energy efficient building design
are well known. Don’t lose sight of them:
• Good insulation
• High levels of air tightness
• Limited thermal bridging
• Maximise natural light
• Reduce solar gains
• Simple HVAC systems are easier to control and
monitor
Lessons Learnt Continued
Issues encountered:
• Difficult to assess the performance of certain sustainable features due to
lack of consideration to monitoring at the design stage.
• Initial resistance from some stakeholders not use to sharing information with
third parties.
• Challenging to interpret some of the data received without knowing the day
to day activities in the building.
Conclusions
• Post Occupancy Evaluations can provide feedback on how a buildings are
performing against original concept.
• The assessment of the hard technical measures such as energy use must be
performed in tandem with soft analysis from the building users in order to
provide meaningful results.
• The process allows operational savings to be identified that might never be
spotted in the normal day to day operations of a building. Hence the
importance of using third parties.
• It provides good quantitative data on how a building is performing that can be
used to inform future building projects.
• The techniques can be applied to assess existing poor performing buildings.
Keeran Jugdoyal
Senior Engineer
keeran.jugdoyal@fgould.com