This document summarizes the key findings from a study conducted by Will Ray of the Carbon Trust on specifying low carbon buildings. The study found that while refurbishments can deliver carbon savings of 10-50%, predicted savings are often not realized due to risks like improper commissioning and increased unregulated loads. For new buildings, predicted performance is often not achieved and initial data shows as much as a 40% performance gap compared to designs. Ensuring good commissioning, energy management practices, and engaging owners are keys to success. The Carbon Trust is developing guidance and case studies to help address performance risks and better realize potential carbon savings.

1. Specifying Low Carbon Buildings
Recognising and reducing the risks
Will Ray
Specifying Low Carbon Buildings Conference
7/10/2010

2. Agenda
Building the Future, Today - the big picture
Low Carbon Building Accelerators – background
What we found
Doing it better

3. Building The Future, Today
Transforming the carbon and economic
performance of the buildings we work in

4. Building the future, today
“What would a carbon reduction target of at
least 80% mean for non-domestic buildings
in the UK?”

5. The average building in 2050 needs to
be 4 DEC ratings better than today
Source: DCLG, Carbon Trust analysis

6. Big opportunity, big challenge
A transformation of
the buildings industry
is required, along with
government policies to
overcome the large
number of barriers to
more low carbon
buildings
We need
better buildings,
used better

7. Agenda
Building the Future, Today - the big picture
Low Carbon Building Accelerators – background
What we found
Doing it better

8. Objective
Accelerate take-up & impact of low-carbon
technologies & approaches in new non-domestic
buildings & refurbishments by:
– Raising awareness of & demonstrating the
business case for developing low carbon buildings
– Identifying barriers preventing low-carbon
outcomes & presenting evidence-based options for
overcoming them
– Reducing the quantitative data gap in non-domestic
buildings energy research & policy

9. Background
Insights from real projects
– Project team experiences, modelled
& measured data
– Monitoring operational performance vs predicted
9 low carbon refurbishments running since 2005
– Encouraging take-up of low-carbon measures
19 low carbon new build running since 2006
– projects going beyond Part L (2006) from “large”
stream of DECC LCBP funding

10. Examples

11. Where are we now?
Largest operational building study since PROBE
– 8 projects complete, 18 still in monitoring
Key piece of Carbon Trust research
– Influential for our design advice service
– Basis of our refurbishment guide
Engaging with industry & clients

12. Agenda
Building the Future, Today - the big picture
Low Carbon Building Accelerators – background
What we found
Doing it better

13. Refurbishments deliver
carbon savings, but….
10-20% for lighter „refresh‟ refurbishments
30-50% for „deep‟ refurbishments
Activity changes can increase energy use &
offset savings
Building Refurb type CO2 Data type
saving
Small Retail Refresh 1% Monitored
Large Retail 1 Refresh 18% Monitored
Large Retail 2 Refresh 12% Monitored
Bank Branch Refresh -1% Monitored
Pub Refresh -12% Estimated
Accommodation Deep 41% Monitored
Office 1 Deep 51% Estimated*
Office 2 Deep 43% Estimated*
Leisure Centre
Source: Carbon Trust analysis (preliminary)
Deep -41%
* - Monitoring in progress
Estimated*

14. Key wins - Chillers
45%
saving

15. New build can perform,
but…
Performance data still being collected
Early evidence suggests many projects are not
performing as intended

16. Performance appears to be
unrelated to cost
Cost data is still to be compiled.
– Preliminary evidence suggests cost of low carbon
often “lost in the noise” of building costs OR
– You can build a cheap low carbon building or an
expensive one
Example: 2 adjacent office buildings, near
identical design & size
– One building was cost-engineered by different
contractor, dropping cost by >25%
– Operational energy data shows cheaper building
performs significantly better

17. Carbon performance prediction
doesn’t account for risks
> 50% of projects
monitored significantly
underperformed
compared to design
stage predictions
Initial data suggests
the gap is around 40%
There is a lack of
available benchmark &
performance data to
bridge the gap
Source: Carbon Trust analysis, RIBA

18. There are many sources of
risk, including
Procurement methods, contracts & project
management
Commissioning
Energy metering & monitoring processes
“Unregulated” loads
Missed opportunities
BMS & control systems
Renewable heat technologies
System complexity

19. A skilled & engaged party, with a
long-term interest, is key to success
Example 1: Office building owner-occupier with
in-house technical team
– Knowledge built from previous smaller projects
– Tight process control
Example 2: Client with deep green brand
– Combined with a planning obligation that included
energy performance target for year 3
Example 3: Biomass ESCO for a community
heating system
– Contractual interest in technology performance
– Long-term experience imported from Europe

20. Commissioning is critical for
low carbon buildings
> 40% of projects did not properly commission
all building systems
All new building projects required extended
bedding-in periods (typically > 1 year)
– to improve operation & realise benefits of low
carbon technologies
Typical impact currently being quantified

21. Relationships between commissioning
& energy efficiency measures
Source: LBNL Commissioning report

22. The tools of good operational energy
management are often forgotten
> 50% of projects had energy metering
problems making energy management and fault
diagnosis difficult.
– Combination of equipment and ICT issues
related to issues in design, installation &
operation that go beyond the scope of the
existing Part L requirements
> 80% of new buildings did not receive log
books as required in Part L
Regular detailed checks of performance data
particularly energy were not done by FM staff for
most projects

23. Increases in “un-regulated”
loads present a major risk
Most projects (% to be confirmed) had large “un-
regulated loads” (e.g. office or catering
equipment)
Increases in expected “un-regulated loads” offset
carbon saving made in the building design or with
low carbon technologies for many projects

24. Bank Branch
1%
New Unregulated
10%
15%
loads
Un-Regulated
29%
kgCO2/m2/yr
50%
90%
71%
Regulated
Post refurb
opportunity
is in
50%
regulated
loads
Source: Carbon Trust analysis

25. Even with a focus on carbon,
opportunities are being missed
>50% of refurbishments didn‟t improve building
fabric
All refurbishments left some energy saving
opportunities remaining after refurbishment
Example: large retail store
Source: Carbon Trust analysis

26. Agenda
Building the Future, Today - the big picture
Low Carbon Building Accelerators – background
What we found
Doing it better

27. Low Carbon Refurbishment
Guide
The key intervention
points for a low
carbon approach to
refurbishment

28. Film case studies
Refurbishment
– MoD
– Whitbread
– Hampshire County Council
New build
– Royal Horticultural Society
– Stoke Local Service Centre
– Pembrokeshire College
– Edge Hill University
– Fairglen Eco-community
– Woodbrook housing development

29. Further resources to come
GSHP Commissioning
PV Managing Risk
Natural ventilation Design to
Biomass & community performance gap
heating (Carbon Buzz
BMS & Controls collaboration)
Metering & monitoring Procurement
(WRAP collaboration)
Retrofitting
renewables Building performance
& carbon (PROBE lite)
Data archive

30. Questions?
will.ray@carbontrust.co.uk
www.carbontrust.co.uk/buildings

31. The Carbon Trust is grant funded by the Department for Environment,
Food and Rural Affairs, the Department for Business, Enterprise and
Regulatory Reform, the Scottish Government, the Welsh Assembly
Government and Invest Northern Ireland.
Whilst reasonable steps have been taken to ensure that the information
contained within this presentation is correct Will Ray, the Carbon Trust, its
agents, contractors and sub-contractors and the Government give no
warranty and make no representation as to its accuracy and accept no
liability for any errors or omissions.
The contents of this presentation are the copyright of the Carbon Trust
and may not be copied or republished without the prior written consent of
the Carbon Trust. The trademarks, service marks and logo used in this
presentation are the property of the Carbon Trust and no licence or right is
granted to use any such marks or logo.
© The Carbon Trust 2010. All rights reserved.
The Carbon Trust is a company limited by guarantee and registered in
England and Wales under Company Number 4190230 with its Registered
Office at: 8th Floor, 3 Clement‟s Inn, London, WC2A 2AZ.