Garages should be included if heating is provided within the garage from the main central heating system.
They should not be included where the garage is thermally separated from the dwelling and is not heated by the central heating system. Thermal separation of the unheated garage is detailed as follows:
- If the wall between the dwelling and the unheated garage is well insulated or the external garage wall is poorly insulated, the garage is unlikely to reach similar temperatures to the dwelling and is therefore thermally separated. This garage is not included as part of the dwelling.
- If the unheated garage is likely to reach the same or similar temperatures as the dwelling, then the garage should be included as it is not thermally separated. This occurs when there is little or no insulation between the dwelling and garage and the garage external wall is insulated and has similar U-values to the other external walls of the dwelling.