Technical Booklet F2 Conservation of Fuel and Power in Buildings Other Than Dwellings·Page 60·3.64
Limitations on enlarged or new windows, doors and rooflights
When windows, pedestrian doors or rooflights are enlarged or newly created, the total area expressed as a percentage of total floor area must not exceed relevant values from Table 3.1 unless compensating measures are made elsewhere.
If a window, pedestrian door or rooflight is enlarged or a new one created, the total area of windows, pedestrian doors and rooflights expressed as a percentage of the total floor area of the building should not exceed the relevant value from Table 3.1 unless compensating measures are made elsewhere in the building.
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