'Conventions for U-value calculations' guides
the architect and specifier for calculating
U-values by:
- indicating the methods of calculation appropriate for different construction elements: roofs, walls, floors, basements, windows and doors
- providing further information about using the methods
- providing data relevant to typical UK constructions.
Particular guidance is given on thermal conductivity of materials, and on various issues commonly arising when calculating U-values and how they apply to different construction types.
This 2006 edition of the guide is fully updated in line with Part L of the Building Regulations that came into effect in April 2006. 44 pages.
Contents:
1 Introduction
2 Numerical methods and simplified methods
- Numerical methods
- Simplified methods
- Numerical and simplified methods used together
- Thermal bridging at junctions and around openings
3 Thermal properties of materials and products
- Declaration of thermal properties of products
- Values for use in calculations
- Masonry
- Concrete beams and concrete screeds
- Insulation materials
- Gypsum plasterboard
- Structural timber
- Metals and alloys
- Thermal conductivity of other materials
- Reflective foil products
4 Issues concerned with U-value calculations
- Surface resistance
- Mortar joints in masonry construction
- Voided masonry units
- Foam-faced blocks
- Timber fraction for timber-framed walls
- Timber fraction for other elements
- Plasterboard wall lining
- Airspace resistance
- Corrections to thermal transmittance
- Metal-faced roofing and wall cladding
- Light steel-framed walls
5 Elements adjacent to an unheated space
6 Expression of results
7 U-values for walls
8 U-values for roofs
9 U-values for floors
- Slab-on-ground floor (ground-bearing floor slabs)
- Suspended floors
- Floor exposed on underside
10 U-values for basements
- Heated basements
- Unheated basements
11 U-values for windows, roof windows and rooflights
- Roof windows and rooflights
12 U-values for doors
Appendix A: Elements adjacent to an unheated space
Appendix B: U-values of uninsulated floors
References and further reading
Other publications that may also be of interest
Part L explained - The BRE guide
Conventions for calculating linear thermal transmittance and temperature factors