Minister says good air ventilation is just common sense


Building and Construction Minister Shane Jones says extractor fans are not compulsory, but it makes common sense to ensure good ventilation in new houses.
Whangarei mayor Stan Semenoff has been quoted as saying: “The Building Code says you must have an extractor fan in the kitchen (for a new house). No one ever died when we were kids from the smell of bacon and eggs being cooked.”

He is also reported as saying that the Building Code standards are too high and are “gold plated”.
“Mayor Semenoff might have been trying to emphasise his frustration with the building code, but the fact is you do not require an extractor fan, but you require proper ventilation as a health precaution, and that is just common sense,” Mr Jones says.

“Proper ventilation is essential to minimise the health risks to people from mould because of moisture from respiration or cooking. There is also the risk of a lack of oxygen without adequate ventilation.”

The Minister says the Building Code is not a “gold plated standard” but a set of practical standards designed to ensure New Zealanders live in good, well built houses without compromising their safety or health.

“The Building Code has performance requirements, which include spaces within buildings having a means of ventilation with outdoor air that will provide an adequate number of air changes to maintain air purity, and that buildings have a means of collecting or otherwise removing (among other things) cooking fumes and odours from the space in which they are generated,” Mr Jones says.

These requirements date from 1992 when the Building Code was first issued as a regulation.
The Acceptable Solution G4/AS1 provides an approved means of complying with the ventilation requirements of the Building Code.

For houses, natural ventilation of occupied spaces can be achieved where the area of openable windows and other openings is no less than 5% of the floor area.
For most houses natural ventilation through windows is the obvious and most practicable solution. The Acceptable Solution G4/AS1 also provides a solution for mechanical ventilation (such as an extractor fan) where natural ventilation is not possible.

Designer flexibility

“The designer has the flexibility to choose to provide natural ventilation (as above) or mechanical ventilation, or a combination.
“The designer also has the flexibility to specifically design for ventilation, provided the performance meets the Building Code requirement to maintain air purity,” Mr Jones says.

“The recent review of the Building Code identified that the expression ‘adequate’ was not specific, and could lead to problems with interpretation.
“It does not provide a clear statement of the required air purity. The review recommended a change to the Building Code to clarify what is meant by adequate air quality, based on health criteria,” Mr Jones says.

“This change will provide clarity for specific design, and enable designers and Building Consent Authorities to be clear about the solution being proposed which complies with the Building Code.

“It is a criteria which the New Zealand public should be pleased about, because it spells out the need to ensure quality in buildings and housing construction.
“I also welcome any constructive solutions Mr Semenoff may have in regards to all the issues he has raised, and I look forward to discussing them with him soon,” Mr Jones says.