Technical Booklet F1 Conservation of Fuel and Power in Dwellings·Page 22·2.9
Conservatories and highly glazed spaces without thermal separation
A conservatory or similar highly glazed space without thermal separation from the dwelling must be treated as an integral part of the dwelling and included in TER, DER calculations and air pressure testing.
Where a new dwelling incorporates a conservatory or similar highly glazed space which does not have thermal separation from the rest of the dwelling, it should be regarded as an integral part of the dwelling and be included in the calculation of the TER and DER and in the air pressure test.
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