THE BUILDING REGS
To improve thermal efficiency there are building regulations for new build, renovation and replacement work. The regulations can be found in these documents, thermal efficiency is expressed as a U-value.
- England & Wales: Part L Building Regulations
- Northern Ireland: Technical Standard F1
- Scotland: Technical Handbook Domestic, Sec 6 (energy).
WHAT EXACTLY IS A U-VALUE?
Put simply, it’s the measurement of the rate of heat loss through a material. The less heat is lost, the lower the U-value. Calculating U-values can be quite complex: heat loss is worked out by measuring the temperature difference on either side of 1m2 of material.
Heat can leak through any external surface in a home, but most escapes through the walls and loft space.