BRE Housing Design Handbook Chapter 11 Thermal Insulation英文电子书.pdfVIP

Building Research Establishment Report CVSfB 81(A3) 1993 BRE housing design handbook Energy and internal layout -... . Energy Efficiency Office Chapter 11 Thermal insulation Thermal insulation Introduction Thermal insulation The quantity of heat needed to maintain comfortable temperatures in a house depends on how well it is insulated. A poorly insulated house needs a great deal of heat to keep it warm and it cools down quickly when the heating is turned off. It is likely to suffer from condensation on the inner surfaces of its exterior walls, even when it is well heated, which could cause damage to decorations and encourage mould growth. Installing thermal insulation is often relatively easy when the house is being built but becomes very difficult or uneconomical at a later stage, unless it involves the straightforward task of filling empty wall cavities, or laying quilts in accessible roof voids. The design and construction of the house is therefore very likely to constrain its level of thermal insulation for the lifetime of the house. This is especially so for floor and wall insulation. Design decisions about thermal insulation can therefore have long term consequences, perhaps anticipating a time when energy supplies could be considerably more costly than at present. Thermal insulation is recognised as an important factor in house design in the Building Regulations (and their counterparts in Scotland and Northern Ireland) which make provisions to ensure that adequate standards of thermal insulation are met. Since the levels of thermal insulation set out in the Building Regulations are only minimum requirements, insulation standards above the minimum are recommended in new housing. Any extra costs are likely to be small in comparison with the overall cost of the