Do I Legally Need an Extractor Fan in My Kitchen?

If you’re renovating your kitchen or building a new home in New Zealand, you’ve probably asked: Do I legally need an extractor fan in my kitchen? The answer isn’t a simple yes or no - it depends on your situation, your location, and when your house was built. But here’s the truth: in most cases, yes, you do need one - and not just because it’s nice to have. It’s a building code requirement.

What the New Zealand Building Code Says

The New Zealand Building Code (NZBC) is the rulebook for all construction and renovation work. Under Clause G12 (Ventilation), kitchens must have adequate ventilation to remove moisture, heat, and cooking odours. The code doesn’t say ‘extractor fan’ by name, but it does require a mechanical ventilation system that can remove at least 15 litres of air per second (L/s) continuously, or 80 L/s intermittently.

That’s the key: mechanical ventilation. Opening a window doesn’t count unless it’s the only option - and even then, it’s rarely enough. Most modern kitchens are sealed off from the outdoors, with double-glazed windows and tight seals for energy efficiency. Without an extractor fan, steam from boiling water, grease from frying, and moisture from dishwashers build up. That leads to mould, peeling paint, warped cabinetry, and even structural damage over time.

When Is an Extractor Fan Required?

Here’s when you’re legally required to install one:

• You’re building a new home
• You’re doing a major kitchen renovation that involves moving walls, plumbing, or electrical systems
• You’re converting a non-kitchen space (like a garage or lounge) into a kitchen
• Your existing kitchen lacks any form of mechanical ventilation

If you’re just swapping out a broken extractor fan for a new one - same size, same location - you’re usually fine. But if you’re upgrading to a more powerful model or changing the ducting, you’ll need to make sure it meets current airflow standards.

Local councils in New Zealand, including Wellington City Council, enforce these rules during building consent applications. If you apply for consent and your plans don’t show a compliant extractor fan, they’ll reject it. No consent = no legal work. And if you skip consent and get caught, you could be forced to remove the work or pay fines.

What Counts as Compliant?

Not all extractor fans are created equal. A cheap 50-watt fan that just spins quietly won’t cut it. To meet NZBC standards, your fan must:

• Extract at least 80 L/s when turned on (intermittent mode)
• Be ducted directly to the outside - not into the roof cavity or attic
• Have a backdraft damper to stop air from flowing back in
• Be installed within 1.5 metres of the cooking appliance
• Be controlled by a switch that’s easy to reach - not hidden behind a cabinet

Many people think a rangehood with a light and a fan is enough. But if the fan is only rated for 40 L/s and vents into the ceiling space, it’s not compliant. That’s a common mistake. I’ve seen homes where the fan is ducted into the roof, and the homeowner didn’t know it was illegal until they got a mould inspection.

What About Older Homes?

If your house was built before 2004, the rules were looser. Many older homes have windows above the stove or just rely on natural airflow. That’s grandfathered in - you’re not forced to retrofit unless you’re doing a major renovation.

But here’s the catch: if you sell your house, a building inspection might flag the lack of proper ventilation as a defect. Buyers are increasingly aware of indoor air quality. A mouldy kitchen or damp walls can drop your home’s value. And if you’re applying for a home loan, lenders sometimes require a building inspection - and they might ask you to fix it before approving the sale.

What Happens If You Don’t Install One?

Ignoring the rule doesn’t mean you’ll get fined overnight. But the risks are real:

• Mould grows on walls, ceilings, and inside cupboards - especially in corners behind the fridge or near the sink
• Condensation drips from windows and causes rot in timber frames
• Grease builds up on ceilings and light fittings - a fire hazard
• Odours linger, making your home smell like fried onions for days
• Insurance claims for water damage or mould may be denied if the home doesn’t meet building code standards

In Wellington, where humidity is high and winters are damp, kitchens without extractor fans are among the top causes of mould-related repairs. One 2023 report from the Wellington City Council found that 37% of homes with reported mould had kitchens without mechanical extraction.

What Are Your Alternatives?

Some people ask: Can I use a recirculating rangehood instead? The answer is no - not if you want to meet the code. Recirculating hoods filter grease and odours through charcoal filters and blow the air back into the room. They don’t remove moisture. That’s why they’re banned for new installations in kitchens under NZBC.

What about a whole-house ventilation system? Yes - if your home has a heat recovery ventilation (HRV) system that meets the 80 L/s intermittent airflow requirement and is designed to serve the kitchen, you might not need a separate fan. But it has to be documented and certified. Most HRV systems are designed for general air exchange, not targeted kitchen extraction. Unless your installer can prove it handles kitchen loads, you still need a dedicated extractor.

How to Install a Compliant Extractor Fan

If you’re doing it yourself, here’s what to do:

1. Choose a fan rated for at least 80 L/s (look for the label - many list it in cubic metres per hour: 288 m³/h = 80 L/s)
2. Install it directly above or within 1.5m of your cooktop
3. Run ducting straight to the outside - avoid bends, and use rigid metal ducting, not flexible plastic
4. Seal all joints with silicone or foil tape - air leaks defeat the purpose
5. Install a backdraft damper at the outlet point
6. Wire it to a switch near the kitchen entrance, not hidden behind a door

For a 3m x 4m kitchen, a 100 L/s fan is ideal. It’s quiet, efficient, and gives you room to breathe. Brands like Broan, Zephyr, and extractors from local suppliers like Vent-Axia or Fantech meet these specs and are commonly used in New Zealand homes.

When to Call a Professional

You don’t need an electrician for a simple fan swap - but you do if you’re running new ducting through walls, cutting into roof space, or dealing with complex venting. A licensed builder or ventilation specialist can ensure your installation passes inspection. They’ll also know the local council’s expectations. In Wellington, some inspectors are stricter about duct length and bends than others.

And if your fan is broken? Don’t just unplug it. A non-working extractor fan is still a code violation. Replace it with something that meets the standard - even if your old one worked fine for 20 years. The rules changed for a reason: we now know how much damage poor ventilation causes.

Final Thoughts

Yes, you legally need an extractor fan in your kitchen in New Zealand - unless you’re in a very old home with no renovations. It’s not a luxury. It’s a health and safety requirement. Mould isn’t just ugly - it’s linked to asthma, allergies, and long-term respiratory problems. And fixing it later costs more than installing the fan upfront.

Think of it like smoke alarms. You don’t ask if you need one - you install it because the law says so, and because it protects your family. Same with extractor fans. Get the right one, install it right, and you’ll save money, avoid health risks, and keep your home in good standing.