Insulating Historic Buildings

Environmentalism is not about saving the planet. It's about saving mankind. This planet will do very well without us!

The Historic Towns Forum in Oxford held in October explored the rationale and methodology of insulating historic buildings to meet modem ecological requirements - or not, as the case may be. Conference started with a basic premise - half the world doesn't believe in global warming, half the world doesn't understand it and at least half don't listen! And even those who do are not yet prepared to give up their comfortable life styles to adopt green technologies. Almost all sane thinking scientists and politicians now believe that we have to create a low carbon economy or we won't have an economy, an environment or a planet fit to live on.

A second premise is that a considerable number of historic buildings are inherently thermally efficient, a premise endorsed by Prince Charles who sent the opening message to the conference - "Historic buildings have thick walls and small windows built by local craftsmen, true vernacular". N.B. This is obviously a Cotswold point of view (stone walls) rather than the half timbered Suffolk cottage with nothing but fresh air between the studs.

The UK has set a target to cut carbon emissions by 80% by 2050. While there is a zero-carbon target for new buildings there is no such target for existing building stock, yet over 70% of the building stock of the future already exists today.

But many historic buildings are not inherently energy-efficient in day-to-day use. However, as the Prince of Wales' Regeneration Trust's 'Green Guide for Historic Buildings' demonstrates, they can be sensitively adapted to reduce energy consumption whilst still retaining their special historic character. Those with thicker walls have thermal mass which helps to even out changes in temperature and if the floor and roof are well insulated, the windows and doors fit properly, and the walls are pointed or lime-rendered sufficient enough to resist driving wind and weather, the building will stay warm and dry without unnecessarily high energy usage.

(to be continued) John Norman