Is this different from a standard pre-purchase pest and building inspection?

Yes. A standard inspection reports on current condition and defects. This service specifically assesses feasibility for a planned rebuild, extension or duplex development, which needs construction and site-planning knowledge.

Should I get this before or after making an offer?

Ideally before, or with a finance/inspection clause in the contract, since the findings can change your build budget or whether the site suits your plans at all.

Does it cover subdivision potential for duplex or multi-unit builds?

A building consultant can flag obvious site constraints, but subdivision feasibility (R-codes, frontage, easements) usually needs a town planner or surveyor alongside this inspection.

Pre-purchase building and structural inspection before you buy a block or knockdown property

Before signing a contract on a property you plan to knock down, extend, or renovate, it pays to get an independent read on what you are actually buying. This differs from a standard pest and building report done for any home purchase: buyers going down the custom build, extension or duplex development path need someone who understands construction feasibility, not just current condition.

A building consultant engaged at this stage checks things a general inspector might not flag as relevant: whether existing footings could be reused, whether the site has fall or drainage issues that will add to excavation costs, whether retaining walls are adequate, and whether services (power, gas, sewer connection points) sit where a rebuild or extension would need them.

This is especially relevant on tight inner-Perth blocks or older suburbs like Bayswater, Mount Lawley and Victoria Park where knockdown-rebuild and duplex activity is common, and site conditions vary block to block.

What it costs

Priced as a one-off inspection fee, generally scoped to the size and accessibility of the property. Sites with pools, retaining walls, sloping blocks or suspected asbestos take longer to assess and cost more. Get this done before your finance and building contract dates lock in, not after.

Top 3 by our score

Ranked from our published scoring of public Google reviews for building consultant.

1. Locale Homes
5.0★ · 333 reviews

94
2. New Home Building Brokers
4.9★ · 155 reviews

91
3. ProConsult Building Inspections
5.0★ · 454 reviews

90

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FAQ

Is this different from a standard pre-purchase pest and building inspection?: Yes. A standard inspection reports on current condition and defects. This service specifically assesses feasibility for a planned rebuild, extension or duplex development, which needs construction and site-planning knowledge.
Should I get this before or after making an offer?: Ideally before, or with a finance/inspection clause in the contract, since the findings can change your build budget or whether the site suits your plans at all.
Does it cover subdivision potential for duplex or multi-unit builds?: A building consultant can flag obvious site constraints, but subdivision feasibility (R-codes, frontage, easements) usually needs a town planner or surveyor alongside this inspection.

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