Due Diligence Checklist for Buying a House in Australia (2026)

What due diligence is

Due diligence is everything you investigate before committing to buy a property. The investigation falls into three layers: the physical property (is it structurally sound, free of pests, well-maintained?), the legal stack (clear title, no nasty encumbrances, contract terms acceptable), and the price (does this reflect the suburb, the property condition, and the market right now?). Each layer independently can kill a deal; you check all three before signing.

The blunt rule: it’s much cheaper to walk away from a bad property than to fix it after settlement. The total cost of full residential due diligence (~$1,500–$3,500) is small relative to any one defect you might find.

When to do it

Timing depends on the sale method.

Private treaty

You can typically include the property contract as subject to building and pest inspection and subject to finance. Once your offer is accepted, you have the cooling-off period (3–14 days depending on state and contract) plus any subject-to deadlines to complete due diligence. If the inspections reveal serious issues or finance falls through, you can withdraw with deposit refunded (or partial penalty depending on state).

Auction

Auction contracts are unconditional from the fall of the hammer. You can’t make the bid subject to inspections, finance, or anything else. This means all due diligence must happen beforeyou bid. In active auction markets you’ll often pay for inspections on multiple properties you don’t win. Frustrating, but the alternative (skipping due diligence to save money on losing bids) is much worse.

Off-market

Off-market sales typically run as private treaty with conditional contracts. The benefit is no auction pressure; the cost is less competitive tension on price. Standard due diligence timeline.

Physical property checks

Independent inspections of the physical property:

• Building inspection: licensed inspector reviews structure, roof, foundations, walls, electrical, plumbing, drainage, weatherproofing. Cost $300–$600 for a typical 3-bed house, more for larger or older properties.
• Pest inspection: licensed pest controller checks for termite activity, termite damage, borers, rodents. Often bundled with building inspection ($400–$800 combined). Critical for any timber-frame Australian home, particularly QLD, NSW north coast, parts of VIC.
• Asbestos assessment for properties built before 1990. Asbestos in good condition isn’t necessarily a deal-breaker, but you need to know what’s there.
• Pool inspection (where applicable): cost $250–$500. Pool issues are expensive: leaking liners, structural damage, non-compliant fences all cost five figures to fix.
• Septic system check for rural properties: $300–$600. Failing septic systems require replacement at $10,000–$30,000+.
• Independent valuation (optional but useful): a registered valuer gives an independent opinion of market value, particularly useful if you’re negotiating against a real-estate-agent appraisal. Cost: $400–$800.

Read the inspection report yourself. Don’t just rely on the inspector’s verbal summary. Cross-reference any flagged issues against repair cost estimates from a licensed builder before deciding to proceed, renegotiate, or walk.

Legal and contract checks

Your conveyancer or solicitor runs the legal due diligence. You engage them before the offer or bid, not after. Their job:

• Title search: confirms the seller actually owns the property and there are no undisclosed parties on the title.
• Encumbrance check: any caveats, easements, restrictive covenants, mortgages, or unpaid rates registered against the title. Easements (right-of-way over your land for utilities or neighbour access) can materially affect what you can build on the property.
• Zoning verification: confirms the property is zoned for residential use and that any future plans (extending, building a granny flat, converting to dual occupancy) are at least possible.
• Planning history: was the existing structure built with council approval? Unapproved structural work creates a financial liability for the buyer that the seller often doesn’t disclose.
• Contract terms review: special conditions, settlement period, deposit, inclusions list, vendor warranties. Many contracts have boilerplate that disadvantages buyers; your conveyancer flags any clauses you should negotiate.
• Property certificates: rates certificate (outstanding rates), water certificate, land tax certificate. Outstanding rates at settlement are typically apportioned between seller and buyer.
• Section 32 (VIC) / Seller Disclosure (QLD from August 2025) / Contract annexures (NSW) review: state-mandated seller disclosure documents. Your conveyancer reads them for both what’s in them and what’s suspiciously absent.
• Special characteristics check: heritage listing, bushfire-prone-land mapping, flood mapping, contamination notations, mine subsidence districts.

Price and market checks

Independent of the inspections and legal work, you need to know whether the price is reasonable:

• Comparable sales (last 90 days): pull every sale in the suburb from realestate.com.au, domain.com.au, or a paid comparable-sales database. Filter to similar property type, similar bedrooms/bathrooms, similar land size. Adjust each comparable up or down for differences. The resulting range is your honest price expectation.
• Suburb price trend: is the suburb’s median price rising or falling? Days on market trending up or down? Both should inform your offer.
• Per-square-metre check (units especially): comparing $/m² across recent sales in the same building or comparable buildings normalises across different unit sizes.
• Cost of repairs or upgrades: if the inspection flags work, get a builder estimate of the cost. Subtract from your offer price if you’re proceeding.
• Independent valuation (optional): a registered valuer’s opinion as a sanity check.

Use our best suburbs and median price lookupas starting points; cross-reference against the agent’s claims.

Extra checks for units and townhouses

Strata-titled properties have a whole second layer of due diligence:

• Strata report (as discussed in FAQ above): non-negotiable.
• Recent body corporate financials: sinking fund balance, current administration fund, special levies in the last 3 years, planned major works.
• Insurance coverage: building, public liability, voluntary insurance. Underinsured buildings expose owners to top-up levies after major incidents.
• Owners corporation / strata bylaws: pet rules, short-term rental restrictions (Airbnb), renovation approval rules, balcony rules, smoking rules.
• Litigation history and disputes: ongoing or recent legal disputes can mean special levies. Defects claims against builders for newer buildings are common and material.
• Capital works plan for the next 10 years: what major works are planned, when, and how funded.
• Unit utilisation: percentage owner-occupied vs investor-tenanted. High investor ratios (60%+) often correlate with poorer building maintenance and more transient tenant issues.

Extra checks for acreage and rural

• Water source: town water, bore, tank, or river. Reliability and quality testing.
• Septic system (no town sewer): age, condition, recent maintenance records.
• Power supply: connected, solar with battery, off-grid. Upgrade costs if any.
• Bushfire zone: BAL rating (Bushfire Attack Level). Properties in BAL-FZ and BAL-40 zones have stringent and expensive building requirements.
• Flood zone: check council flood maps. Even partial flood exposure significantly affects insurance cost and resale.
• Access: confirm legal access road (some rural properties have informal track access that isn’t legally guaranteed).
• Mining and resource leases: in some states, mining leases override surface rights. Affects QLD coal regions especially.
• Easements: powerlines, water pipes, drainage easements crossing rural properties are common and can constrain future building.

Extra checks for new builds and off-the-plan

• Builder solvency check: search the licensee, look for recent insolvencies in the corporate group, check the home warranty insurer’s site for any project issues.
• Builder licence + insurance: confirm current and adequate home warranty insurance.
• Defects liability period: the post-handover window where the builder must fix defects. Typically 12 months in most states, longer in some.
• Sample units/recent completed projects: walk through completed projects from the same builder before committing.
• Off-the-plan: sunset clauses: the date by which the project must complete or you can withdraw with deposit refunded. Critical for buyer protection.
• Off-the-plan: substitution / variation clauses: how much the developer can change from the marketed plan without your consent. Watch for clauses allowing significant size or feature changes.
• Off-the-plan: deposit security: confirm the deposit is held in trust by a third party, not at-risk in the developer’s operating accounts.

Red flags worth walking away from

Some findings should end your interest immediately:

• Unapproved structural work. A second storey, granny flat, deck, or major renovation done without council approval is your problem post-settlement. Cost to legalise (often involving demolition plus reapproval) can be $30,000–$200,000+.
• Significant active termite damage not yet remediated. Remediation cost depends on extent.
• Structural movement / cracking requiring engineering remediation.
• Asbestos in poor condition in occupied areas. Friable asbestos remediation is $20,000–$80,000+ and Class A licensed work.
• Body corporate funding crisis: empty sinking fund plus planned major works ahead means a special levy ahead.
• Contamination on the title: former industrial site, fuel station, dry cleaner, or noted in EPA records. Affects insurability, financability, future remediation cost.
• Easements affecting buildability: a sewer easement crossing the part of the block where you wanted to extend.
• Heritage listing you didn’t know about: limits what you can change. Not necessarily a deal-breaker but should be priced in.
• Underquoting by the agent so significant that the property is well out of your range: walk early.
• Seller’s urgent settlement insistence without a reasonable explanation: occasionally indicates hidden issues.

The complete pre-purchase checklist

Print this. Work through each item.

Pre-offer / pre-auction

• ☐ Pre-approval letter in hand (see home loan pre-approval guide)
• ☐ Conveyancer engaged
• ☐ Reviewed Section 32 / disclosure / contract with conveyancer
• ☐ Building + pest inspection booked and report received
• ☐ Strata report received (if unit/townhouse)
• ☐ Pool / septic / asbestos / specialty inspections as needed
• ☐ Comparable sales pulled and price range agreed
• ☐ Visited the property at different times of day
• ☐ Drove the suburb at night and on weekends
• ☐ Checked council planning maps (zoning, future development, flood, bushfire)
• ☐ Checked the agent’s recent sold listings for over/underquoting patterns
• ☐ Walked the boundaries, confirmed with fence lines and title plan
• ☐ Checked NBN, mobile coverage, public transport practicalities
• ☐ Checked schools, hospitals, supermarkets (if relevant)
• ☐ Insurance quote obtained (factor into ongoing cost)

Post-offer / cooling-off period (private treaty only)

• ☐ Final conveyancer contract review
• ☐ Any inspection-flagged work re-checked with a licensed builder/specialist
• ☐ Lender valuation (typically lender-driven, but track it)
• ☐ Insurance arranged for settlement date

Pre-settlement

• ☐ Pre-settlement inspection, confirms property in contracted condition, all inclusions present
• ☐ Final settlement figures from conveyancer (rates apportionment, etc.)
• ☐ Funds ready to clear
• ☐ Utilities arranged from settlement date (electricity, gas, water, internet)
• ☐ Change of address paperwork started (banks, employer, electoral roll, etc.)