Exploring the time dimension of low carbon retrofit: owner-occupied housing. Presentation summary of academic article: Fawcett, T. 2013 Building Research and Information. http://dx.doi.org/10.1080/09613218.2013.804769

1. Environmental Change Institute
Exploring the time dimension of low carbon retrofit: owneroccupied housing
Tina Fawcett
Building Research & Information, 2013 p1 -12
http://dx.doi.org/10.1080/09613218.2013.804769

2. Context & research questions
Low carbon retrofit* occurs on a very small scale in the UK – probably
only in hundreds of properties per year, compared with the hundreds of
thousands needed annually to meet our national carbon reduction goals.
Low carbon retrofit is most commonly understood as a one-off activity.
However, an alternative model is of retrofit occurring ‘over time’- a more
gradual process which still delivers significant carbon savings.
Does this occur in real life?** And if so:
•Could over-time low carbon retrofit be an attractive option for owneroccupiers?
•Could over-time low carbon retrofit deliver sufficient carbon and energy
savings?
•What would be needed to support over-time low carbon retrofit?
*Here defined as reducing carbon emissions by at least 60%
** SPOILER ALERT: yes it does
My research
questions

3. ‘Over time’ low carbon retrofit does exist
The Superhomes database had timing information about 35 owneroccupied low carbon retrofits. Of these, 17 were retrofitted as a
one-off package of work and 18 retrofitted over time.
Several householders described their low carbon retrofit
experience as a journey or a continual process: Where it’s been sensible
“Our journey has
definitely been step by
step, and we keep
going.
(Superhomes owner,
Coventry)
It hasn’t really been a
project, but a process of
steady improvement.
(Superhomes owner,
Steeple Claydon)
and affordable over the
years we’ve done things
to make the house more
energy efficient and
comfortable.
(Superhomes owner,
Wendover)

4. Could over-time low carbon retrofit be an
attractive option for owner-occupiers?
Buildings, people and time: Over-time retrofit fits with existing
patterns of regular spending on home maintenance, repair and
improvement. An over-time low carbon retrofit, involving a
series of distinct stages, fits better with most people’s previous
experience of commissioning and managing smaller scale
building works than a one-off whole house low carbon retrofit. It
can be added on to existing ‘conventional’ building works.
Cost: We don’t yet know whether one-off or over-time retrofit
would be more expensive.
Disruption: Disruption patterns are very different for one-off
and over-time works – and personal preferences may differ.
Answer: Yes, for some.

5. Could over-time low carbon retrofit deliver
sufficient carbon and energy savings? (1)
One-off retrofit
Over-time retrofit
Carbon
emissions
time
or

6. Could over-time low carbon retrofit deliver
sufficient carbon and energy savings? (2)
Modelling work (EST 2011) suggests in theory that step-wise
retrofit can lead to high levels of carbon saving.
Analysis of the potential for ‘locking out’ savings (by retrofitting
to a sub-optimal level) shows it may be no greater for over-time
than for one-off retrofits.
However, to meet very ambitious retrofit standards such as
ENERPHIT, which require extensive changes to the building
fabric, an over-time approach is not likely to be appropriate.
So – there are signs it could deliver high (but perhaps not the
very highest) levels of savings, but not a great deal of empirical
evidence as yet.

7. What would be needed to support overtime low carbon retrofit?
Creating new policy
New policies to support over-time retrofit could include:
•a suitable metric
•additional training for building professions and trades
•development of Low Carbon Retrofit Plans
Amending existing policy
•Measures to reduce cost to householders (e.g. subsidies, subsidised
loans) to apply also to over-time retrofit.
•Innovation on technologies and management of over-time retrofit.
•Training to help professionals to spot low carbon retrofit opportunities
when doing other work, working in a way that is compatible with future
upgrades to the property, and understanding Low Carbon Retrofit
Plans.
•Creating obligations to act – e.g. a programme of increasing
minimum standards over time

8. Conclusions
Over-time low carbon retrofit has been shown to exist in the real world
and to deliver significant carbon savings. However, the empirical
evidence base is small.
An over-time model implicitly assumes that home owners and
professionals will be in a process of continual change, adapting
themselves, their skills and their homes to a low carbon future.
The over-time approach is likely to increase the accessibility of low
carbon retrofit by spreading costs and aligning low carbon retrofit with
normal repairs/ upgrades. It offers a vision and mechanism of
migrating from a current situation of very little low carbon retrofit to a
much improved housing stock and more engaged population.
While many detailed research questions remain, preliminary analysis
has shown that over-time retrofit is worthy of further exploration.

9. Acknowledgements & further research
The research reported in this paper was jointly funded by the Engineering and
Physical Sciences Research Council (EPSRC) and EDF through the People,
Energy and Buildings programme (EP/H051163/1). Any views expressed in
this paper are those of the author alone and do not necessarily represent the
views of the funders.
Since completing this paper, colleagues and I have continued to work and
gather evidence on this topic. Look out for further papers by Fawcett, T and
Killip, G in the coming months.
November 2013

10. Acknowledgements & further research
The research reported in this paper was jointly funded by the Engineering and
Physical Sciences Research Council (EPSRC) and EDF through the People,
Energy and Buildings programme (EP/H051163/1). Any views expressed in
this paper are those of the author alone and do not necessarily represent the
views of the funders.
Since completing this paper, colleagues and I have continued to work and
gather evidence on this topic. Look out for further papers by Fawcett, T and
Killip, G in the coming months.
November 2013