Further to the letter from B and S Rushbridge (AJ 27.7.00), in my experience we do already have homes that require virtually no heating.
I lived in a 1980s flat built to regulation standards that was so warm that the windows were always ajar to keep the rooms from overheating.
Overheating was a serious problem in the kitchen, even in winter. The central heating only came on for a few minutes in the morning or evening if the flat had been empty.
When people say we do not have the same insulation standards as our continental neighbours, remember that we also do not have their very cold winter climates.
The trend for window sizes to be reduced to save energy also caused problems in this house. Not only did it severely restrict the view, but it also meant that the electric light was needed most of the time.
The flat was dark and depressing, and current research on photobiology shows that a lack of adequate daylight can cause severe health risks. When were minimum window sizes removed from the Building Regulations? Decent-sized windows are essential for both energy conservation and health.
I now live in a detached 1970s house, with double glazing, and cavity wall fill (although only 50mm loft insulation) and very large picture windows. The energy costs are surprisingly low, perhaps because of solar gain, and the house is bright and cheerful. I would never again live in a small-windowed building.
I have not seen a single piece of feedback on how buildings built in the '80s and '90s are performing in thermal terms, or how satisfied the occupants are with them. If my experiences are common (anecdotal evidence from people living in recently built homes suggests they are) and if the proposed Part L comes into force unamended, then we are about to waste an enormous amount of energy in producing unnecessary insulation and burning electricity for light, to produce buildings that are unhealthy and disliked by the occupants.
M Reeve, Croydon