by [Brian Anderson], Ludmilla Kosmina (18-Nov-2020)
The guidance in this document is concerned with the calculated U-values of new building elements, including walls, roofs, floors, windows and doors. Guidance is given on: thermal conductivity of materials (section 3); various issues that commonly arise when undertaking U-value calculations (section 4); various types of construction element, identifying which of the issues mentioned in section 4 apply to which construction type (sections 7 to 14). The document does not reproduce the details of the calculation methods, for which the reader is referred to the relevant British Standards and other sources (see References and further reading).
2 U-value calculation: Simplified methods and numerical methods
4 Details of U-value calculations
5 Elements adjacent to an unheated space
6 Expression of results and areas to which U-values apply
7 U-values for walls
8 U-values for roofs
9 U-values for floors
10 U-values for basements and swimming pools
11 U-values for windows, roof windows and rooflights
12 Curtain walls
13 Dynamic transparent building elements
14 U-values for doors
15 U-values of existing (old) walls, roofs, and floors in dwellings
16 Appendix A: Glossary/definitions
17 Appendix B: U-values of uninsulated floors
18 Appendix C: Example of calculating U-value for elements
19 References and further reading
The 2002 edition of BR443 can be obtained here.
The 2006 edition of BR443 can be obtained here.