BWOF Kitchen Extract Requirements

A building warrant of fitness covers everything on your compliance schedule. This guide narrows in on one line of it: the commercial kitchen extract system, which sits under specified system SS9.

If you own or manage a building with a commercial kitchen in it, SS9 is usually the item most likely to cause you grief, because it is the one that degrades fastest and the one that is easiest to under-service.

Your Compliance Schedule Is the Rule Book, Not the Regulations

This is the single most important thing to understand, and it is where most people go wrong.

There is no national rule that says “clean your kitchen extract every six months”. What binds you is your building's own compliance schedule, issued by your territorial authority. It sets out the inspection, maintenance and reporting procedures for each specified system in that specific building.

Two buildings on the same street can have genuinely different SS9 obligations, because they have different systems, different uses, and schedules written at different times by different people. So the first job is always the same: read your compliance schedule and find the SS9 entry.

If you cannot find your compliance schedule, your council holds a copy. Ask for it before you do anything else.

What an SS9 Entry Typically Requires

Compliance schedules vary, but for a kitchen extract system the SS9 procedures usually cover some combination of the following.

• Filter cleaning. Often monthly or more frequently, and usually a task for kitchen staff rather than a contractor. Grease filters are the first line of defence and the easiest thing to neglect.
• Ductwork cleaning. The full run from canopy to discharge, at a stated frequency. This is the specialist job.
• Extract fan servicing. Including the impeller and housing, which collect grease that filters and duct cleaning do not reach.
• Airflow verification. Checking the system still moves the air it was designed to move.
• Visual inspection of the canopy and access panels. Including whether panels are present, sealed and openable.
• Record keeping. A log of what was done, when, and by whom.

The annual sign off is the Form 12A, issued by an IQP registered for SS9 with your council. It certifies that every one of those procedures was fully complied with over the previous 12 months.

Cleaning Frequency Is Driven by How Hard the Kitchen Works

Where a schedule gives a range, or where you are trying to work out whether the stated frequency is still realistic, the honest test is how much grease the kitchen produces.

• Heavy use. Charbroiling, wok cooking, deep frying, 24 hour operations. These load a system fast and typically need quarterly attention or better.
• Moderate use. A standard restaurant or pub kitchen running lunch and dinner service. Usually somewhere around every six months.
• Light use. A cafe doing mostly toasted items, a staff kitchen, a school canteen running term time only. Often annually is enough.

We go into this in more detail in how often commercial kitchen ducts should be cleaned. The short version is that a schedule written five years ago for a cafe does not fit the same premises once it becomes a burger joint.

If your use has changed, tell your IQP. A compliance schedule can be amended, and it is far better to amend it than to quietly fall short of it.

The Fail Points We See Most Often

These are the things that stop us signing a Form 12A, in rough order of how often they come up.

• No access panels, or too few. If we cannot get into a duct run, we cannot clean it and we cannot inspect it. A long horizontal run with a single panel at one end is not inspectable. Retrofitting panels is a small job that solves a recurring problem.
• Access panels that have been sealed or built over. Usually by a well meaning fit out. A ceiling goes in, and the panel disappears behind it.
• Grease in the fan housing. Filters get changed, ductwork gets a wipe, and nobody touches the fan. It is often the dirtiest component in the system.
• No records for the in house tasks. The contractor tasks are documented, but the monthly filter cleans that staff were supposed to do have no log at all. That is a genuine gap in compliance, not a technicality.
• Missing or damaged fire dampers. Where the schedule requires them, they have to be there and they have to work.
• Discharge pointing the wrong way. Usually a nuisance complaint before it is a compliance issue, but it can become both.

What the Records Need to Show

An IQP signing your SS9 certificate needs to see a year of evidence, not a clean duct on the day.

What good evidence looks like:

• Dated cleaning reports covering the canopy, filters, full duct run and fan.
• Before and after photography for each clean, so the condition is documented rather than asserted.
• A log of the in house tasks, with dates and initials. A laminated sheet by the canopy works perfectly well.
• Records of any repairs, panel installations or fan work.
• The previous year's Form 12A.

Keep all of it for at least two years after issue. Councils audit, and when they do they want the reports behind the certificate.

Who Is Responsible

The building owner holds the legal obligation for the BWOF. In a leased commercial kitchen, the lease usually pushes the day to day maintenance onto the tenant.

That split is where things fall over. The owner assumes the restaurant is handling it, the restaurant assumes the landlord's facilities contractor is handling it, and the ductwork gets cleaned by nobody for three years.

Whoever you are, get it in writing. One sentence in the lease or the maintenance agreement naming who books the SS9 clean and who holds the records will save a lot of argument at BWOF time.

A Simple Annual Rhythm

1. Pull your compliance schedule and read the SS9 entry. Note the required frequencies.
2. Diarise the cleans backwards from your BWOF anniversary date, leaving a buffer.
3. Put the in house filter tasks on a visible log in the kitchen.
4. Book the SS9 inspection with enough time to fix anything found before the anniversary.
5. File the Form 12A with the reports behind it.

Do that and the BWOF becomes an administrative formality rather than an annual panic. Our BWOF inspection checklist covers the wider building, and commercial kitchen compliance in NZ covers the rest of the obligations that sit alongside SS9.

Ductflow handles both halves of this: the kitchen extract cleaning and the 12A inspection that certifies it.