Technical Booklet F1 Conservation of Fuel and Power in Dwellings·Page 33·2.56
Building Envelope Construction Standards
The building envelope must be constructed to a reasonable standard ensuring insulation is reasonably continuous across the whole envelope and actual air permeability remains within set limits.
The building envelope should be constructed to a reasonable standard such that the insulation is reasonably continuous over the whole building envelope and the actual air permeability is within the set limits.
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