Updated October 2026
Mount Richon sits on the rise between the Armadale plain and the scarp, so retaining work here is about managing a step in the ground rather than holding back a hillside. We connect you with builders who cover the 6112 area.
Common wall situations in Mount Richon
Terracing a yard, driveway and crossover edges, pool surrounds, pad levelling, and replacement of older walls that went in without ag-pipe behind them. Boundary level differences come up regularly, and a wall on or at a boundary needs a building permit at any height along with the neighbour's consent or another authority.
Whether your block is on reticulated sewerage or running its own system is worth establishing before a machine arrives, because where a tank, leach drains or an irrigation area sit decides where the wall line can go, where spoil can be stacked and where its drainage can discharge. Your local government holds the records for your address.
The ground under Mount Richon
Perth is a sand city. Up here it is not. The ground is ironstone and laterite gravel over weathered granite, and the City of Kalamunda records in its Local Planning Strategy that reticulated sewerage is constrained in the Hills because hard granite sits close to the surface and is costly to dig through. That same rock is what a post hole has to get through, so ask any builder how the quote prices a hole that hits it.
Drainage is the thing that actually matters. Water that cannot soak away through rock travels sideways and arrives behind the wall, and the Shire of Mundaring names heavy soils and perched water tables as Hills constraints for that reason. Ag-pipe, free draining gravel, geotextile fabric and a lawful discharge point are not optional line items.
What a wall costs in Mount Richon
As a rough guide, most residential walls run from around $200 to $700 or more per metre for a wall about a metre high, depending on material, height, access and engineering. Those are published Australian guide figures rather than a quote, and rock is the reason a Hills number can sit above them. Read the retaining wall cost guide and then get a price for your block.
Approval, and who to ask in Mount Richon
In WA a retaining wall is exempt from needing a building permit only where it retains no more than 500mm of ground, is not tied to other building work or to holding up the land next door, and is not work of a kind that affects adjoining land. The measurement is the ground the wall retains, not the height of the wall, which catches a lot of people out. All three conditions have to be met, so a wall on or near a boundary needs a permit whatever its height. Development approval under the local planning scheme can be a separate question again, and the rules change, so confirm your wall with the City of Armadale before you build.
On who may carry out the work, WA draws the line by how the work is classified under the building legislation, not by a dollar threshold a homeowner can apply to their own job, and the position for a standalone retaining wall is not something to take from a website. Ask any builder what registration or licence they hold and verify it with Building and Energy, and ask your permit authority what your wall requires. Have the builder lodge a free Before You Dig Australia (BYDA) enquiry before anything is dug.
Frequently asked questions
Repair the old wall or replace it?
If the structure is sound and water is the problem, fixing the drainage can add decades. If posts have snapped or rotted, the face is bulging across several bays, or soil is escaping through it, the wall is finished and patching is money spent twice.
What drainage should a quote include?
Ag-pipe at the base, free draining gravel rather than site spoil, geotextile fabric so the drain cannot silt up, and a lawful discharge point. If those are not itemised, ask why.
Who approves it?
The City of Armadale. The WA exemption covers only walls retaining 500mm of ground or less that are also clear of other building work and of the land next door.
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We also cover nearby Mount Nasura and Bedfordale.