What we look for in Treeby, and why it differs from the suburb next door. 19.1 km from the CBD, 8.5 km from the coast, postcode 6164.
Treeby was established in 2016 out of the part of Banjup north of Armadale Road. What makes it worth inspecting carefully is what was done to the ground first. Land here had been mined for sand, and that mined land was developed into the Calleya estate.
Sand mining removes material and then the site gets filled and re-levelled for housing. That means engineered fill under a substantial part of this suburb, and fill is only as good as its placement and compaction.
So on any block here the site preparation records matter. Fill depth. Compaction testing. Site classification. Where a slab has moved, that history is where to look before assuming workmanship, and the documentation exists because a project of this kind generates it.
Ask for it. Routine request, not an awkward one.
Over eleven hundred house-and-land packages have sold here and a large display village operates in the suburb. Volume building at that scale, by multiple builders competing for the same trades, produces unevenness. Two houses finished the same year can be built to noticeably different standards, so each property is assessed on what it actually shows rather than on an estate reputation.
Everything is post-2016, so handover defects and the defect liability window are the live questions. On a suburb this young a great many houses are still inside it.
The Jandakot Industrial Area forms the northern boundary, bringing heavy vehicle traffic and industrial context to blocks on that side.
New slab construction on engineered fill sits at the low end of termite exposure, and overstating it would be dishonest.
Fill is the thing worth thinking about. Material brought in to replace mined sand comes from somewhere, and fill of unknown composition can contain buried timber and organic matter. None of it is visible and none of it can be removed now.
Every home carries a termite management system with a durable notice recording it. Find the notice and keep it.
Then watch the landscaping, because in an estate where every garden went in within a season or two of handover, soil and paving over the slab edge is the norm. A barrier that cannot be inspected cannot be relied on, whatever was originally installed.
A new house is quick to inspect and the perimeter is where both reports are written. Splitting that across two visits would double the travel and halve the coherence for no gain. Reported under AS 4349.1 and AS 4349.3.
Get the fill and compaction records for the parcel before committing. On former sand-mined land that is the single most useful document a buyer can obtain, and it will not appear in a building inspection.
Staged inspections during construction catch problems at slab and frame, which are visible once and then covered for the life of the house. Condition records apply where a finished home now sits beside a lot about to be built on, which in an estate still selling describes most of them.
Treeby sits on the Spearwood dune system — residual yellow and grey sand over a Tamala Limestone core, with the rock often close to the surface. Limestone near the surface makes for stable footings and expensive excavation. Where the rock is shallow, older houses often sit directly on limestone footings, and those are the ones to look at for rising damp and salt damp at the base of the wall.
What that means in practice, on a house in Treeby:
Landform is assigned from the suburb's position on the Swan Coastal Plain rather than from a site soil test. It tells you what to expect, not what you have. A site classification to AS 2870 is a different exercise and a different report.
Jandakot, Atwell and Banjup sit on the same ground as Treeby, so the footing behaviour and the drainage problems tend to repeat across all of them. If you are comparing houses across those suburbs, you are largely comparing the same site conditions.
Piara Waters is 2.2 km away but sits on the Bassendean dune system; Harrisdale is 3.5 km away but sits on the Bassendean dune system; Canning Vale is 4.2 km away but sits on the Bassendean dune system. That is the useful thing about this part of Perth: the ground can change inside a few kilometres, and with it what an inspection is looking for.
On site classification: any soil zone quoted for a suburb is indicative, inferred from geography rather than surveyed. A real AS 2870 classification comes from geotechnical work on your actual block and can differ from the one next door. We report what we observe; we do not read your soil class off a map.
The inspection is visual and non-invasive, over the readily accessible areas, reported to AS 4349.1. Our inspectors physically enter the roof space, as long as there is sufficient access. Report within 24 hours of the inspection.
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Flat fee, the same in Treeby as anywhere: $440 inc. GST for a pre-purchase building inspection, or $616 inc. GST with the timber pest scope added in the same visit. Full price list →
8.5 km inland through Cockburn, the salt risk in Treeby is real but secondary. The same fee weighs an older roof for corrosion alongside the wet areas, the drainage and the movement patterns the Cockburn stock tends to show.
Pre-purchase building inspection in Treeby →
Building and pest inspection in Treeby →
Yes. Our inspectors physically enter and inspect the roof space, as long as there is sufficient access to do so safely. Where access is restricted, the report says so plainly rather than implying we saw more than we did.
Treeby is 8.5 km from the coast — outside the highest-exposure band, but close enough that salt-driven delignification is worth checking in an older tiled roof.
Within 24 hours of the inspection itself, not 24 hours from booking. On a pre-purchase or pre-settlement job that timing is the whole point, because your leverage disappears once you are committed.
We would rather you checked than took our word for it. These are the bodies that actually hold the records and set the rules:
Tell us about the property and what you need. We'll come back to you with a firm quote and a time.
PERTH