[EN 12792:2003, 75]:environmental condition in a space such that the majority of the occupants should, on a statistical basis, be comfortable.

[AIVC, Air infiltration and ventilation glossary, 1992]:a building whose primary purpose is to provide space for commercial activity rather than domestic. This includes offices, storage, plant, farm, public and some factory classifications.

[AIVC, Air infiltration and ventilation glossary, 1992]:the leakage of air through the building envelope which is directly attributable to flow through cracks around specific doors, windows or other components.Note: it refers to building envelope components.