Site due diligence checklist

Check the flood planning area overlay (1% AEP, 2% AEP, storm tide, etc.). Flood-affected land may require fill, elevated finished floor levels, or restrict habitable use entirely. Some flood categories allow development with conditions; others effectively sterilise the land. Get a hydraulic engineer's opinion for any affected site.

Bushfire Attack Level (BAL) ratings from BAL-LOW to BAL-FZ affect construction cost significantly. High BAL ratings require expensive ember protection, glazing, and non-combustible materials. BAL-FZ can make development economically unviable. Access and defendable space requirements also eat into usable land.

Coastal and low-lying areas often contain acid sulfate soils (ASS). Disturbing these during earthworks can release sulfuric acid, causing environmental damage and substantial remediation costs. Check the ASS overlay and factor treatment costs into your feasibility if present.

Sites over 15% gradient typically trigger additional engineering requirements (retaining walls, stormwater management, geotechnical reports). Sites over 25% gradient become very expensive to develop. Check topographic contours and confirm engineering costs before committing to steep land.

Heritage-listed properties or sites within a heritage precinct face significant design restrictions. Even nearby non-listed buildings can trigger heritage impact assessments. Check both the State Heritage Register and local council heritage registers - they are separate.

Protected trees (on-lot and street trees) may limit building footprint, require protection zones, or need council permits to remove. Vegetation offsets can add unexpected cost. Walk the site and identify any significant trees that overlap your design envelope.

Many inner-Brisbane and Sunshine Coast suburbs have character overlays that restrict demolition of pre-1947 homes and impose design requirements to match existing character. These overlays can prevent knockdown-rebuild scenarios and add to design and approval costs.

A current title search from the Queensland Titles Registry reveals registered owners, caveats, mortgages, charges, and all registered interests. This is non-negotiable and should be done before any offer. Examine every encumbrance - some are deal-breakers.

Easements for drainage, sewerage, electricity, access, and pipelines restrict what can be built over or near them. A drainage easement running through the middle of a site can destroy the feasible yield. Get a survey plan and overlay all easements on your proposed layout before the design is progressed.

Covenants can prohibit multi-dwelling development, require minimum house sizes, dictate materials, or ban dual occupancy outright. Unlike planning rules, covenants are private legal agreements that run with the land and are very difficult to extinguish. Do not assume a planning scheme approval overrides a covenant.

Caveats signal that a third party claims an interest in the property. Unresolved caveats can prevent settlement. Understand the nature and basis of any caveat before proceeding - some are straightforward, others indicate serious title disputes.

Every new lot created by subdivision must have practical access to a road. Battleaxe lots require access handles of minimum width. Confirm the site has or can achieve road access for all proposed lots - including emergency vehicle access where required.

If acquiring a lot within a scheme, review the body corporate (owners corporation) records - levies, outstanding works, disputes, by-laws. Check whether the body corporate will consent to the proposed development and whether any votes or approvals are needed.

Soil class (A, S, M, H, E, P) determines footing type and cost. Class P (problem) soils - reactive clays, loose sands, fill - can multiply slab and footing costs dramatically. Get at least a desktop assessment, and a full geotech report for multi-dwelling sites. Never assume - suburban soil can vary significantly within a single lot.

Former industrial, commercial, or agricultural land may be contaminated. Check the EMR (Environmental Management Register) and CLR (Contaminated Land Register) on the Queensland Environment Department website. A Phase 1 Environmental Site Assessment identifies potential contamination risk without intrusive investigation.

Uncontrolled fill (particularly old demolition rubble or organic material) cannot support engineered footings without remediation. Ask the vendor for any fill records. If the site has been raised or levelled, commission bore holes to determine fill depth and composition.

Increased impervious area from development triggers on-site stormwater management requirements. Some sites require detention tanks, rain gardens, or bioretention cells. Get a preliminary civil drainage assessment to understand the cost and space requirements before finalising your design yield.

Buildings constructed before 1990 may contain asbestos-containing materials (ACM). Demolition requires a licensed asbestos assessor report and licensed removal contractor. Fibrous cement cladding, eaves, and floor tiles are common ACM. Budget for removal and disposal - it adds to demolition cost.

Confirm sewer availability and the nearest connection point. Check invert depth - if the sewer is shallow, gravity drainage from your development may require a pump-out system (expensive ongoing maintenance). Contact the relevant service provider (Urban Utilities, Unitywater, Council) for a pre-lodgement infrastructure inquiry.

Confirm the water main size and pressure can service your intended number of dwellings. Larger developments may require main upgrades at the developer's cost. Get a pre-lodgement infrastructure services report from the water authority - this is often free and avoids major surprises.

Multi-dwelling developments often require substation or transformer upgrades funded by the developer. Ergon/Energex will advise on required network upgrades. This can range from minimal connection costs to $80k–$200k+ for significant capacity upgrades in constrained areas.

New developments must provide telecommunications infrastructure compliant with the Telecommunications (Low-impact Facilities) Determinations. In some areas, developers must fund conduit installation or pay NBN Co connection costs per lot. Confirm with a licensed cabler or NBN Co.

Infrastructure charges (formerly developer contributions) are levied per additional demand unit created. They cover trunk infrastructure - roads, parks, water, sewerage networks. Charges vary significantly by council and development type. Obtain an infrastructure charges estimate from the council or a town planner as an early feasibility input.

Once all constraints are mapped (easements, setbacks, overlays, site cover), commission your architect or town planner to test the maximum achievable yield within the planning envelope. Do this before finalising your feasibility - yield is the primary driver of project return and must be confirmed, not assumed.

Engage a surveyor to prepare a preliminary subdivision layout. Identify the maximum number of lots achievable within the zone minimums, easement constraints, and access requirements. Consider battleaxe vs reconfiguration options. Confirm whether staged subdivision is feasible if cash flow is a concern.

The planning envelope determines maximum yield; the market determines the optimal product mix. Check whether the site supports 2-bed vs 3-bed vs 4-bed configurations, and whether car parking minimums (1 per dwelling, visitor spaces) fit within the buildable area once setbacks and common areas are accounted for.

Assess whether there is potential to achieve more than what is permitted as of right. Could a spot rezoning, MCU, or performance-based variation unlock additional yield? Speak to a town planner about the likelihood and cost - some requests are straightforward, others require significant justification and carry approval risk.

Most Queensland councils offer free or low-cost pre-lodgement meetings where you can discuss your proposed development before lodging a formal DA. Use this to confirm the planning pathway, identify likely conditions, and gauge council's attitude to your proposal. This is one of the best investments of time in the due diligence phase.

Some development applications require referral to state agencies (DTMR for road access, QFES for bushfire, TMR for state-controlled road impacts, DESI for vegetation). Referrals add time and potentially conditions. Your town planner can identify all referral triggers for your project type and location.

The site may have an existing, lapsed, or in-force development approval that could be beneficial (or restrictive). Check council's DA register and the Development.i portal. A superseded DA can sometimes be activated or built upon - confirm with your town planner.

Your town planner interprets the planning scheme, identifies overlays and triggers, advises on approval pathways, and represents you at council. Find one who specialises in your council area - local knowledge of decision-makers and precedents is invaluable. Budget: $3,000–$8,000 for due diligence advisory; more for DA management.

A property solicitor (ideally with development experience) reviews the contract of sale, title, easements, covenants, and encumbrances. They advise on due diligence conditions and protect you at settlement. Do not use a residential conveyancer for development - the issues are more complex.

Commissions bore holes and laboratory testing to classify soil and identify risks. Essential for any multi-dwelling or subdivision project. Early engagement prevents design and cost surprises in construction.

Assesses sewer, water, stormwater, earthworks, and road requirements. Prepares infrastructure services reports and civil design for DA. Essential for subdivision - often needed for multi-dwelling too.

Provides a survey plan showing boundaries, easements, existing structures, and contours. For subdivision, the surveyor prepares the plan of survey for council. Engage early - survey data informs all other professional reports.

At due diligence stage, an architect can quickly test whether the site actually delivers the yield your feasibility assumes. A concept sketch or envelope study ($2–5k) can prevent costly mistakes before you go unconditional.

A QS can provide an order-of-magnitude construction cost estimate at concept stage. This feeds directly into your feasibility model and is worth commissioning before going unconditional on higher-risk or larger sites.