Applicable Standards

Thermal calculations are undertaken in accordance with EN and BS standards, and following guidance published by the BRE, CWCT, GGF and CAB:

• BS EN ISO 13789 Thermal performance of buildings - Transmission heat loss coefficient - Calculation method

• BS EN ISO 6946 Building components and building elements - Thermal resistance and thermal transmittance - Calculation method

• BS EN ISO 10211-1 Thermal bridges in building construction - Heat flows and surface temperatures - Part 1: General calculation methods

• BS EN ISO 10211-2 Thermal bridges in building construction - Calculation of heat flows and surface temperatures - Part 2: Linear thermal bridges

• BS EN ISO 10077-1 Thermal performance of windows, doors and shutters - Calculation of thermal transmittance - Part 1: Simplified method

• BS EN ISO 10077-2 Thermal performance of windows, doors and shutters - Calculation of thermal transmittance - Part 2: Numerical method for frames

• BS EN ISO 13370 Thermal performance of buildings - Heat transfer via the ground - Calculation methods

• BS EN 673 Glass in building - Determination of thermal transmittance (U-value) - Calculation method

• BS EN ISO 12631:2012 - Thermal performance of curtain walling. Calculation of thermal transmittance

• BRE BR 443 Conventions for U-value calculations

• BRE IP 5/98 Metal cladding: Assessing thermal performance

• BRE IP 17/01 Assessing the effects of thermal bridging at junctions and around openings

• BRE IP 10/02 Metal cladding: Assessing the thermal performance of built-up systems which use ‘Z’ spacers

• CWCT Standard for specifying and assessing for heat transfer (the U-value)

• CWCT Guide to good practice for assessing heat transfer and condensation risk for a curtain wall

• CWCT Guide to good practice for assessing glazing frame U-values

• GGF 2.2 Window and door system U-values: Provision of certified data

• CAB Guide for assessment of the thermal performance of aluminium curtain wall framing

• CAB A guide for assessment of the thermal performance of aluminium windows