G4/AS1: Ventilation

G4 VENTILATION ACCEPTABLE SOLUTION G4/AS1 Definitions Appendix B. Definitions These definitions are specific to this acceptable solution. Other defined terms italicised within the definitions are provided in clause A2 of the Building Code. Term Definition Adequate Adequate to achieve the objectives of the Building Code. Atmospheric burner A burner system where all the air for combustion is induced by the inspirating effect of a gas injector and/or by natural draught in the combustion chamber without mechanical assistance. Building Has the meaning given to it by sections 8 and 9 of the Building Act 2004. Building element Any structural and non-structural component or assembly incorporated into or associated with a building. Included are fixtures, services, drains, permanent mechanical installations for access, glazing, partitions, ceilings and temporary supports. Chimney A non-combustible structure which encloses one or more flues, fireplaces or other heating appliances. Chimney back The non-combustible wall forming the back of a fireplace. Chimney breast The front fireplace wall construction above the fireplace opening. Chimney jambs The side walls of a fireplace. Construct In relation to a building, includes to design, build, erect, prefabricate, and relocate the building; and construction has a corresponding meaning. Draught diverter A device, without moving parts, fitted in the flue of an appliance for isolating the combustion system from the effects of pressure changes in the secondary flue. Equivalent The area of an equivalent aerodynamically perfect orifice, and equals the aerodynamic area penetration area required by the natural ventilation device multiplied by the discharge coefficient determined under test. Fire The state of combustion during which flammable materials burn producing heat, toxic gases, or smoke or flame or any combination of these. Fireplace A space formed by the chimney back, the chimney jambs, and the chimney breast in which fuel is burned for the purpose of heating the room into which it opens. Fixture An article intended to remain permanently attached to and form part of a building. Flue The passage through which the products of combustion are conveyed to the outside. Forced or induced An appliance where all or part of the air for combustion is provided by a fan draught appliance or other mechanical device which is an integral part of the combustion system. Habitable space A space used for activities normally associated with domestic living, but excludes any bathroom, laundry, water closet, pantry, walk-in wardrobe, corridor, hallway, lobby, clothes-drying room, or other space of a specialised nature occupied neither frequently nor for extended periods. MINISTRY OF BUSINESS, INNOVATION AND EMPLOYMENT 28 JULY 2025 Page 16