Letter: Inside-out houses

Sir: Your Health Editor's article (13 December) about asthma relief depending on very low humidity levels in our homes, as experienced in Alpine conditions, exposes the poor product of the British building industry.

To build dry houses we need not restrict ourselves to such high sites. We can build dry houses in the UK as long as we insulate them well and place the insulation on the outside.

Over 75 per cent of the houses we build, however, are timber-frame kit houses with a solid skin on the outside and the insulation on the inside; they are prone to condensation as the insulation is not ventilated well enough behind a brick wall.

In nature everywhere the insulation is on the outside - sheep's woolly coats, the bark of trees, our clothing - with the solid mass inside. If we build kit houses inside-out, no vapour barriers are needed to prevent condensation and we would have breathing buildings with solid walls inside that could store heat and retain an inside temperature higher than outside. This, by diffusion, would automatically result in a dryer house and reduce the excessive intake of outside air to ventilate the building, and heat loss.

It is always more intelligent to avoid damp buildings in the first place than to invent costly remedies, such as vapour barriers, dehumidifiers and electric fans that cost energy and are bound to go wrong.


Chartered Architect