Customer Appealing retrofit

Ecobuild this year was as overwhelming in ideas as in products with its excellent seminar series. In the 'Refurbishing Britain' theme, lessons from CALEBRE focused mainly on technical solutions. But as the CA in CALEBRE stands for 'Customer Appealing', Victoria Haines summary of findings on people's appetite for improving their homes was particularly interesting.

After all, if we could get our teenagers to turn down their heating and turn off their lights we would probably be closer to the 80% reduction needed than replacing our boilers with heat pumps.

This is in the wider context that energy efficiency as such is a low priority for most people: comfort yes, cost of fuel yes but reducing carbon emissions no. The evidence suggests that unless there is a simultaneous change in behaviour and attitude, homes refurbished as part of the Green Deal or otherwise will be more comfortable but not reduce emissions.

Barriers to retrofit include the comfortable relationship people have with their homes, particularly older 'hard to treat' properties.  Her evidence shows that most people make the major changes to their homes when they first move in, with a readiness to live with disruption then that they would not tolerate 20 years later.

With the scale of the refurbishment challenge needed we have focused on physical solutions - still with many questions over their effectiveness. Clearly they are important but are only a part of a more nuanced approach needed. 'Hard to treat' solid wall properties are a huge challenge to meeting our emissions reduction targets. Linking a reduction of Stamp Duty to undertaking major Green Deal work would be a neat way of both incentivising energy-saving refurbishment at a point that most suits people, as well as stimulating the housing market.

In the meantime, the bigger question remains - how do we change our behaviours to live within our means?

Healthy Retrofit

A good event on 'Healthy Retrofit' at Cullinan Studio's newly refurbished Foundry building on Wednesday last week, with retrofit challenges and achievements covered by Johnny Winter of Cullinan Studio, Neil May from ASBP and Richard Griffiths of Parity Projects.

The 'Healthy Retrofit' talk was hosted by Cullinan Studio in their new BREEAM 'Excellent' retofit offices.

Brendan Sexton of Cullinan Studio introducing the evening and our latest annual sustainability report.

Johnny Winter of Cullinan Studio began the evening with a talk on the retrofit of 

our Baldwin Terrace studios, including some of the lessons learnt from the process.

Neil May's talk on (a seemingly dry subject) -  'How sustainable products can assist with moisture control in retrofit' - was particularly timely.

Neil May of ASBP.

29% of UK housing stock is solid wall construction. As a nation we have to upgrade it successfully if we are to reduce our carbon emissions and provide comfortable homes that people can afford to heat.

Under the Green Deal, this widespread form of construction is labelled 'hard to treat'.

It's an odd situation to be in. At last, and for all the Green Deal's faults, something is being done to tackle the challenge of widescale retrofit of our existing housing. Now there is a growing pressure to get this work underway. But do we actually have the technical solutions?

The general 'golden rule' for the Green Deal is that the cost of carrying out improvement works is matched by savings in fuel bills. 'Hard to treat' properties can't meet this rule: the cost of insulating solid wall properties far exceeds the savings in fuel bills. To get this work done, additional subsidy is needed. This comes from the utility companies' 'Energy Company Obligation'. This subsidy is not given away but is paid for by a general increase in all our fuel bills. The utility companies are obliged to meet set carbon reduction targets, hence the pressure to get this work underway and fast.

Building Magazine on 8th February reported Encraft's recent study, which showed that the costs of the upgrading 'hard to treat' homes has been woefully underestimated.The effective cost per ton of carbon saved they estimate to be £180 compared with the government's £80, a difference we will all have to bear through increases to our fuel bills.

So it is more than ever important that the technical solutions employed do actually work.

Neil's overriding point was that we do not yet have robust, widely applicable, whole building solutions based on sound science: inappropriate and partial solutions seriously risk causing a new generation of moisture-related problems, from mould growth and ill-health, to fabric degradation and premature decay.

To meet this challenge we need the pace of research and dissemination to accelerate.

In the meantime, we need some good rules of thumb to guide us. In this debate the five 'principles for building' still stand up*. What are they? Two overriding constraints, two overarching objectives, and the fifth a guiding caution.

• 'High to low' restates what should be obvious, that gravity generally makes water flow downhill, that temperature goes from hot to cold, that vapour diffuses from high to low vapour pressure.
• 'Separate lives' reminds us that buildings are assembled in a process and that different materials move and decay at different rates, processes which if ignored cause premature failure.
• 'Continuity' of performance is an implicit objective for the building envelope. The increased performance we now expect from our building envelopes, where internal conditions are held further apart from the external environment, means design has to be more rigorous to achieve this. Continuity of the measures to achieve continuity of performance has become more critical, whether at the air tightness line or thermal insulation. This might be obvious but it is only the Passivhaus standard that appears to recognise that continuity (by truly avoiding cold bridges and demanding a demonstrable air tightness performance) is an essential rather than a nice-to-have. By its nature, 'continuity' is often in conflict with 'separate lives'.
• 'Balance' is the objective that encompasses the equilibrium of environmental conditions, of structural forces, and distribution of resources. Achieving balance is often in conflict with the constraint of 'high to low'.
• The fifth, cautionary principle can be called 'creative pessimism' - accepting that in the world of building what can go wrong at some point will, and creatively anticipating it. I enjoyed Neil's restating this as the 'principle of forgiveness'.

The relevance of all this is that accepting and working with these principles by following some rules of thumb - 'going with the flow' - rather than fighting them against does reduce the risk of failure. Increasing thermal resistance towards the cold side and increasing vapour resistance towards the moist side is one such rule. External wall insulation still needs to be continuous but is inherently less risky than internal linings. Fighting against the principles always requires more highly stressed solutions, such as 100% vapour barriers. That is why we should all be concerned about the prospect of 'hard to treat' homes being internally lined with insulation.

Colin Rice, Cullinan Studio

*Addleson and Rice, Performance of Materials in Buildings, 1991

 Richard Griffiths from Parity Projects.

Q&A session following the three presentations.

The 'Healthy Retrofit' talk was presented by ASBP (Alliance for Sustainable Building Products) which is a cross sector, not for profit organisation, comprising building product manufacturers and distributors, specifiers, designers, architects, contractors, public interest and sustainability organisations, academics and other building practitioners.

The ASBP are committed to accelerating the transition to a high performance, healthy and low carbon built environment by championing the increased understanding and use of building products that meet demonstrably high standards of sustainability.

Demolition or Refurbishment

On Monday evening Prof. Anne Power from LSE gave a thought provoking presentation at the Institute of Civil Engineers. She began by tackling the governments notion of a housing shortage in the UK. We currently have 25million homes (17million 3bed+). Also called into question was the idea that we reuse plastic bags but not a house!

She weighed up the argument for demolition or refurbishment in terms of

1. Economic cost

2. Environmental cost

3. Social Cost

She questioned some of common misconceptions in the refurbishment debate and spoke at length about the green deal.

For an hours watching well spent click on the link below for a recording of the lecture.

https://ice.adobeconnect.com/_a884535394/p36vt59xnyr/?launcher=false&fcsContent=true&pbMode=normal (some compatibility issues for windows 7 users)