Retrofitting insulation and air tightness to existing houses

The reason that good airtightness is so seldom achieved in the UK is that few in the construction industry have the slightest knowledge of what they are discussing with thermal envelopes and so it risks being a case of the blind leading the blind.

 

Progress can be made:

A Victorian solid-walled house in Hereford has been retrofitted to a leakage rate of 0.9 ac/h at 50 Pa as part of the work to bring it up to roughly the Passivhaus Standard.

A mid 20th C cavity-walled house in Oxford has been retrofitted to achieve 3 ac/h @ 50 P. This is the level required by law in new Swedish detached houses 35 years ago i.e. from January 1978.

 

Similar retrofit work to the first project was being done in Canada in the late 1970s. I’ve been informed by this in my own practice and recommendations to clients since 1980.

 

But thermal retrofits are expensive and it seems clear that in towns CHP/DH is cheaper, plus lesser improvements in insulation and airtightness as time goes on and as parts of our buildings are replaced e.g. new roof tiles. I don’t think a Passivhaus retrofit is very likely to stack up financially unless the fuel being displaced is oil or LPG.

 

Regards

 

 

David

 

David Olivier BSc MASHRAE

ENERGY ADVISORY ASSOCIATES

Lower Orchard House

Lyonshall

KINGTON HR5 3LX

T (01544) 340647

d.olivier@energyadvisoryassociates.co.uk

www.energyadvisoryassociates.co.uk

Related Posts

Claverton Group's comment on BBC Radio 4 "You and Your's" on the Energy Gap 13th October 2009 – its cheaper to save than to build.

Leave a Reply

Your email address will not be published.

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>

*