Technical Booklet F1 Conservation of Fuel and Power in Dwellings·Page 34·2.60
Thermal bridging at party walls
Thermal bridges occur where party walls penetrate insulation layers, such as blockwork penetrating insulation at ceiling level, and must be evaluated and accounted for in thermal bridge calculations.
In considering heat losses via party walls it is important to be aware that wherever the wall penetrates an insulation layer, such as when the blockwork of a masonry party wall penetrates insulation at ceiling level, a thermal bridge is likely to occur. This will be the case even when the party wall U-value is zero. The evaluation of thermal bridges should ensure that any bridging at the party wall is taken into account along with other thermal bridges.
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