The standard of ventilation in an NZ property plays a key role in how comfortable and safe an environment the building provides for occupants and visitors. A high standard of ventilation is crucial for replacing hot, stale, and damp air in a building with fresh, cool, and healthy air.
But if you are involved in the construction sector or otherwise responsible for a commercial property, what are the ventilation requirements in NZ for such buildings? Below, we explain the essentials.
An Introduction to Clause G4 Ventilation
It is difficult to have any conversation about commercial ventilation systems in NZ, without referring at some stage to the G4 clause in the New Zealand Building Code. The Building Code is contained in the First Schedule of the Building Regulations 1992. The legal requirements were later amended by the Building Amendment Regulations 1997.
The G4 clause sets out ventilation requirements in NZ for all occupied spaces. It makes clear that spaces in buildings must be provided with adequate ventilation, in accordance with their maximum occupancy and intended use.
What Exactly Does the G4 Clause State?
The text of the G4 clause makes clear that it has the objective of safeguarding people “from illness or loss of amenity due to lack of fresh air.” It therefore sets out a series of performance requirements:
- Spaces within buildings must have means of ventilation with outdoor air that provide an adequate number of air changes so that air purity is maintained
- Mechanical air-handling systems must be constructed and maintained in a way that prevents the multiplication within such systems of harmful bacteria, pathogens, and allergens
- Buildings must have a means of collecting or otherwise removing certain products from the spaces in which they are generated. Cited examples of such products include – but are not limited to – cooking fumes and odours, flammable fumes or gases, and gaseous by-products and excessive moisture arising from commercial or industrial processes
- Contaminated air must be disposed of in a manner that avoids the creation of a nuisance or hazard to people and other property
- The quantities of air supplied for ventilation must satisfy the additional demands of any fixed combustion appliances.
Are you seeking out a roof ventilation system for your property that will help you meet the ventilation requirements in NZ for commercial buildings? If so, please don’t hesitate to contact us for further information about our highly regarded solutions at Roofquip.