A little smoke is okay – but no longer than 15 minutes
Environment Canterbury media release: 30th July 2025
We’re clearing the air on smoky chimneys and what the rules really mean for Waitaha Canterbury households.
There’s nothing quite like the comfort of a warm fire on a cold evening in Waitaha. But although wood burners keep many homes cosy, they can also contribute to poor winter air quality across the region – especially when they produce too much visible smoke for too long.
We’ve had a number of queries recently about the rules for smoky chimneys. Some residents are surprised to learn that a little smoke is okay - but it's the timeframe that matters.
Let’s clear things up.
You’ve got a buffer – but it’s a short one
Under the Canterbury Air Regional Plan, visible smoke from your chimney is allowed for up to 15 minutes when starting your fire, and for up to five minutes when reloading it.
This short buffer gives your fire time to establish or recover. After that, your fire must burn without producing visible smoke. A little white steam or heat shimmer is fine, but thick grey or black smoke means something’s not burning well.
Find out more about the Canterbury Air Regional Plan.
These rules are in place to help reduce the pollution that builds up in our air during cold, still winter nights – especially in our region’s eight airsheds.
These are urban areas across Waitaha, where air quality is monitored and managed to meet the National Environmental Standards for Air Quality (Air Quality NES).
Learn more about air quality monitoring at the Canterbury airsheds.
Find out more about the National Environmental Standards for Air Quality.
Why smoky chimneys matter
When wood isn’t burning cleanly, it releases tiny particles (called PM10 and PM2.5) that can stay suspended in the air. These particles are small enough to enter your lungs and even your bloodstream, and are linked to serious health problems – especially for children, older people, and those with asthma or heart conditions.
Reducing smoke from home heating is one of the most effective things we can do to improve winter air quality in Waitaha.
“We all want warm, healthy homes – and we also want to protect the air we breathe,” air quality compliance spokesperson Brian Reeves said.
“The good news is, it doesn’t take much to burn better. Just a few small changes to how you light and operate your fire can make a big difference.”
Tips for burning smoke-free
Good firewood and good fire habits go a long way toward keeping your chimney smoke-free. Here’s how to get it right:
- Use only dry, untreated wood. Wet or green wood doesn’t burn well and creates excessive smoke.
- Store your wood in a dry, covered space for at least 12 months before use.
You can also purchase wood from a local Trusted Good Wood Merchants. We have reviewed and accredited these retailers for providing dry, seasoned wood.
- Don’t dampen the fire down overnight. When a fire is dampened down, it usually smolders rather than burning cleanly, and this releases more smoke and harmful pollutants. A hot fire is a clean fire.
- Stack your fire loosely when lighting or reloading. This allows airflow and helps wood burn efficiently.
- Use plenty of kindling to get a hot burn going quickly.
- Never burn rubbish, plastics, or treated timber. This is not only illegal but is also toxic.
You can find more burning tips and advice online.
Still seeing smoke? It might be time to check your burner
If you’re following all the good burning tips and still seeing smoke from your flue, your wood burner might not be working properly – or may be too old to meet today’s air quality standards.
Most urban areas in Canterbury require ultra-low emission burners, and open fires are not allowed in Clean Air Zones.
Learn about Clear Air Zones in Canterbury.
Report smoke or air pollution online or by calling us on 0800 765 588 (24-hours).