Perth’s winter rain doesn’t arrive politely. It comes in sudden bursts, and a roof with nowhere to send it will pick its own route, usually down a wall or into the eaves. For gutters Perth rules are a mix of national building code and local council requirements, and that mix surprises people.
Do you have to have gutters in Western Australia? Not by one blanket law. The National Construction Code applies its gutter standards only where drainage is needed. But under common law and the Local Government Act 1995, owners must keep roof runoff on their own block, so most WA houses end up with gutters, downpipes and soakwells.
What the code says about gutters Perth builders install
An eaves gutter is the channel along the edge of a roof that catches rainwater and carries it to the downpipes. A downpipe is the vertical pipe that takes that water down to the ground. Simple enough. The rules start when you actually fit them.
The Australian Building Codes Board says its Housing Provisions for gutters and downpipes (NCC 2022, Part 7.4) need only be applied when drainage systems are necessary. Once you install one, the standards apply. Eaves gutters must handle a storm with a 5% annual exceedance probability, roughly a 1 in 20 chance in any given year. Overflow measures must handle a 1% storm, roughly 1 in 100. Overflow measures are the built in escape routes, such as slotted gutters or weirs, that stop a full gutter spilling back into your eaves.
The same board adds a blunt note. Too few downpipes, or downpipes in the wrong spot, are a frequent cause of poor roof drainage.
Why Perth councils expect gutters, downpipes and soakwells
A soakwell is an underground tank that lets water seep away without damaging the ground around it. That’s how the City of Joondalup describes it. The city also says owners have a statutory obligation, under common law and the Local Government Act 1995, to confine runoff within their boundaries. The City of Wanneroo says the same in its information sheet, and both point to soakwells or spoon drains fed by gutters and downpipes as the most effective fix.
The City of Perth takes a firm line too. Stormwater stays on site, and if that isn’t possible, an approved detention system comes first.
Details vary by council. Here’s how four of them put it.
| Council | Downpipe rule | Where the water goes |
|---|---|---|
| City of Joondalup | About 1 per 15 m2 of roof, no more than 12 m apart | Confined to your own block |
| City of Wanneroo | No more than 12 m apart | Confined to your own block |
| City of Kwinana | No more than 12 m apart | Soakwells at least their own width from buildings and boundaries |
| City of Perth | Not stated | Kept on site, or approved detention before connecting to city drains |
Can a house go without gutters?
A gutterless roof isn’t banned by name in the national code, because those provisions apply only when drainage is necessary. Your council still wants to know where the water goes, though. For a typical house, that’s a hard question to answer. Water falling off a roof edge lands right beside your walls and footings, which is exactly where you don’t want it. Some sheds and outbuildings get away with it.
Ask your building surveyor or council before assuming your roof can.
Bushfire areas add a materials rule
WA’s Building and Energy division says construction requirements in designated bushfire prone areas sit in the Building Code and Australian Standard AS 3959, and they cover gutters and downpipes. Its advice is to use non combustible gutters and leaf guards, which help stop embers igniting leaf litter. Gutter guards aren’t compulsory, but Stratco notes that where you fit one in a bushfire prone area, AS 3959 says it must be non combustible.
What a builder or council will look at
Roof drainage is a system, and these are the pieces that get checked:
- Roof area, and how much water it sheds in a heavy storm.
- The number and position of downpipes.
- Overflow measures for a blocked or overwhelmed gutter.
- Where each downpipe discharges: soakwell, tank or detention.
- Distance from walls, boundaries and neighbours.
- Gutter material, especially in bushfire prone areas.
How to get a fair quote
Ask the installer to point at each downpipe on the plan and say where it ends up. Ask which overflow measure they’re using, because a high fronted gutter without one is a risk. Get the material, colour and warranty in writing. Gutters Perth’s website lists a 20 year Colorbond product warranty and a 5 year workmanship warranty, so compare that against any other quote. You can browse Colorbond colour options before you call.
For a sense of what work costs, our guide on how much it costs to fix gutters in Australia breaks down current price ranges. Already have gutters? Our post on regular gutter cleaning covers upkeep, and a quick look at the about page tells you who you’re dealing with.
The mistake people make most? Fitting a gutter and forgetting the downpipe. A gutter that empties onto paving beside the fence just moves the problem to your neighbour.
Picture a homeowner who adds a patio roof with one downpipe, pointed at the slab by the boundary. Dry in summer, fine. Then the first big winter storm sends water under the fence. (An example only, not a real client.)
My view: treat the downpipe and soakwell as half the job. A gutter is only as good as wherever it sends the water.
Need help with a gutter installation, a worn section that needs roof repairs, or a one off gutter cleaning? Those are the three jobs we handle most.
FAQ
Are gutters compulsory on houses in Western Australia?
Not under one blanket rule, but in practice, yes. The national code only applies its gutter standards where drainage is needed, while councils like Joondalup and Wanneroo require owners to confine roof runoff to their own block. Gutters, downpipes and soakwells are how most houses do that.
How far apart can downpipes be?
No more than 12 metres, according to the Cities of Joondalup, Wanneroo and Kwinana, who cite the Building Code. Joondalup also asks for roughly one downpipe per 15 square metres of roof.
Do I need soakwells if I have gutters?
Usually. Councils point to soakwells, spoon drains or similar catchment so roof water stays on your property. Kwinana adds a placement rule: keep soakwells at least their own width away from buildings and boundaries.
Are gutter guards required in a bushfire zone?
No, they’re optional. If you fit them in a bushfire prone area, AS 3959 requires non combustible guards, as Stratco explains.
Can roof water run onto my neighbour’s property?
No. Joondalup’s guidance says owners must confine runoff within their boundaries. If water is crossing a fence, the downpipe and soakwell need another look.
Not sure what your roof needs? Ask for a free roof inspection in the Perth metro area through our contact page or call 0468 476 111.