Development due diligence is the set of planning, title and servicing checks you run on a site before you exchange, so you know what can lawfully be built there and what it will cost to get approved. In NSW it comes down to ten checks: zoning, the LEP development standards, title restrictions, the Section 10.7 certificate, flood, bushfire, heritage and trees, sewer and stormwater, vehicle access, and contributions. Most sites that fail do so on two or three of these, and all ten can be checked in a few days for far less than the cost of a wrong purchase.
Key takeaways
- Zoning tells you what is permissible, but the LEP development standards (lot size, FSR, height) decide how much you can build.
- Title restrictions in a Section 88B instrument can override the planning controls and must be read before exchange.
- The Section 10.7(2) and (5) certificate is the fastest way to find flood, bushfire, heritage and contamination flags on a parcel.
- A site with no lawful stormwater discharge point or no sewer nearby is often unbuildable at the yield you paid for.
- Section 7.11 or 7.12 contributions can add tens of thousands of dollars per additional dwelling and belong in the feasibility from day one.
Why the order of the checks matters
We run the checks in sequence, cheapest and most decisive first. If the zoning does not permit the use, nothing else matters. If the lot size kills the yield, there is no point ordering a flood study. Working this way, a buyer in Penrith, Liverpool or Blacktown usually knows within a day if the site deserves a full report or a polite pass.
The ten checks
1. Zoning and permissibility
Find the zone on the NSW Planning Portal Spatial Viewer, then read the land use table in the council LEP. A dual occupancy, multi dwelling housing or a secondary dwelling each appear as separate items, and a zone can permit one and prohibit another. Do not rely on what the neighbours built; permissibility changes with LEP amendments.
2. Development standards
Read Part 4 of the LEP: minimum lot size, floor space ratio, height of buildings, and any local clauses for dual occupancy lot sizes or subdivision of dual occupancies. These are development standards, so a shortfall needs a Clause 4.6 request, not just a good argument in the SEE. Under Penrith LEP 2010, for example, the dual occupancy minimum lot size differs by area, and it is the map that decides, not the zone.
3. Title search and 88B instrument
Order the title, the deposited plan and any Section 88B instrument from NSW Land Registry Services. Look for easements for drainage or services, restrictions on the use of land (single dwelling only, building envelope, materials), and positive covenants for on-site detention. A restriction limiting the lot to one dwelling stops a duplex regardless of what the LEP says, and lifting it can involve the council or a benefited neighbour.
4. The Section 10.7 certificate
The Section 10.7(2) certificate lists the prescribed matters under the Environmental Planning and Assessment Act 1979: zoning, the instruments that apply, whether the land is flood, bushfire or contamination affected, heritage listing, and which contributions plans apply. The 10.7(5) part adds council information such as flood levels or road widening. Order both. The vendor’s contract copy is a good start but can be months old.
5. Flood
Flood affectation is the constraint we see most often in the Hawkesbury-Nepean, along South Creek and Eastern Creek in Blacktown and Penrith, and across parts of Liverpool and Fairfield. Check the LEP flood planning map, the 10.7 certificate and the council flood study. A site inside the flood planning area may still be developable with raised floor levels, but a site in a floodway or a high hazard area often cannot be intensified at all.
6. Bushfire
Bush fire prone land mapping is prepared by the council and certified by the NSW Rural Fire Service. If the parcel is mapped, any new dwelling must meet Planning for Bush Fire Protection 2019, which sets asset protection zones and construction levels under AS 3959:2018. On fringe sites in the Hills, Hawkesbury and Wollondilly, the required asset protection zone can consume the rear of the block.
7. Heritage, trees and biodiversity
Check if the site or an adjoining lot is a heritage item or inside a conservation area, since both change what a council will accept. Then look at the trees. Councils protect significant trees through the DCP, and a mature tree in the middle of the block can sterilise the second dwelling’s footprint. Where native vegetation is involved, the biodiversity provisions may require offsets or an assessment.
8. Sewer and stormwater
Two questions decide most Western Sydney sites: where is the sewer, and where does stormwater lawfully go? Sydney Water’s requirements for building near or over assets are set out on its developing and building page. For stormwater, a lot that falls to the street is simple. A lot that falls to the rear needs an inter-allotment drainage easement, a pump-out system where the council allows it, or it does not work. Our civil colleagues at Contrive Consultants settle this before we finalise a yield.
9. Access and traffic
Confirm frontage width, the number of driveway crossings the council will allow, and whether the road is classified. A driveway onto a classified road brings State Environmental Planning Policy (Transport and Infrastructure) 2021 into play and often a referral to Transport for NSW. Corner lots, bus stops and power poles all shape where driveways can go.
10. Contributions and approval pathway
Section 7.11 or 7.12 local contributions are levied per additional dwelling or lot, and the growth councils (Camden, Liverpool, Blacktown, The Hills) can carry high rates. Add the Housing and Productivity Contribution where it applies. Finally, decide the pathway. If the site and design fit the Codes SEPP, a complying development certificate can save months, but a single non-compliance tips the project into a DA. Our DA or CDC pathway advice covers this decision.
What a deal-breaker looks like for each check
| Check | Where we look | Usual deal-breaker |
|---|---|---|
| Zoning | LEP land use table | Proposed use is prohibited in the zone |
| Standards | LEP Part 4 and maps | Lot below the dual occupancy or subdivision minimum |
| Title | 88B instrument | Single dwelling restriction with no clear path to release |
| Flood | 10.7 certificate, flood study | Floodway or high hazard category |
| Bushfire | BFPL map, PBP 2019 | Asset protection zone leaves no building envelope |
| Services | Sydney Water, site levels | No lawful discharge point and no easement available |
| Contributions | Council contributions plan | Contributions exceed the margin on the extra dwelling |
Mistakes we see buyers make
- Trusting the listing. “Duplex potential” in an advertisement is not a planning assessment. Agents rarely check lot size maps or 88B instruments.
- Buying on zone alone. R2 permits dual occupancy in many councils, but the lot size clause decides if your particular block qualifies.
- Skipping the survey. A detail survey with levels is the only way to confirm fall, and fall decides drainage.
- Ignoring the neighbours’ approvals. A recent duplex next door tells you the council’s current attitude and the drainage solution that worked.
- Leaving contributions out of the feasibility. They are payable before the construction certificate and they do not negotiate.
Frequently asked questions
What does development due diligence cost compared with a feasibility study?
A planning due diligence report is a desktop and site review of the ten checks above, and it is usually a small fraction of the cost of a full feasibility with architectural concepts and quantity surveyor pricing. Do the due diligence first, then spend on design only if the site passes.
Can I do development due diligence myself?
You can read the zone and lot size on the Planning Portal and order a title search yourself. The harder parts are reading local LEP clauses correctly, interpreting flood and bushfire mapping, and judging whether a drainage problem has a practical fix, which is where a planner earns the fee.
How long does due diligence take before exchange?
A desktop review usually takes a few working days once the 10.7 certificate and title documents are in hand. If you are buying at auction, allow at least a week so that a survey or a quick civil opinion can be arranged if the first pass raises a question.
Is a cooling-off period long enough to check a site?
The standard five business day cooling-off period in NSW is tight but workable for a desktop due diligence if the documents are ordered on day one. Ask for a longer period in the contract if the site has flood, bushfire or drainage flags.
URBA prepares development due diligence reports for buyers across Sydney, the Central Coast and regional NSW, covering all ten checks with a clear yield opinion before you commit. If you are weighing up a site in Western Sydney or anywhere in the state, request a fee proposal and send us the address.