Key takeaways
- A cost line is only as reliable as the document it came from. Every line needs a named evidence owner.
- Keep land-attached costs separate from non-land development costs, or the residual land value subtraction double-counts the site.
- Acquisition costs are the largest cheque you write and are not part of a GST margin scheme cost base.
- Transfer duty, planning fees, contributions and headworks are set by state and council, and most index on 1 July.
- Every dollar figure here is an illustrative example, not a quote for any site.
What Most Property Development Costs Checklists Get Wrong
Search for a property development costs checklist and you will find the same article repeatedly: category names, a percentage beside each, no indication of where the numbers came from. A feasibility is not a list of headings; it is a set of numbers somebody has to produce, defend and update.
So this checklist applies four questions to every line: who supplies the number, when the cash leaves, what is inside the line, and what is deliberately outside it. A line that cannot answer all four is not a cost — it is an assumption wearing a number.
The Master Checklist
| Cost category | Who supplies the number | When cash leaves | What it excludes |
|---|---|---|---|
| Acquisition price | Contract of sale; valuer for market value | Settlement | Transfer duty and legals |
| Transfer duty | RevenueSA, or your conveyancer | Settlement | Development costs, legals and option fees, none of which form part of a GST margin scheme cost base |
| Legals and due diligence | Your solicitor; the reports commissioned | On engagement and at settlement | — |
| Planning and building fees | PlanSA fee notice; the relevant authority | At lodgement, then on assessment invoice | Consultant fees paid to prepare the application |
| Contributions and headworks | Council, PlanSA, the service authority | Often late, before titles or condition release | Council condition works such as crossovers and drainage |
| Professional fees | Each consultant's own fee proposal | Staged, mostly before the first drawdown | Builder preliminaries, which sit inside construction |
| Construction and civils | Quantity surveyor, or a tendered builder price | Progress claims against certified work | Contingency and escalation, held separately |
| Contingency | You, benchmarked to QS advice and the lender's requirement | Not scheduled; drawn as variations and latent conditions land | Nothing. It is not a substitute for costing known scope |
| Finance | Financier's terms sheet; the cash flow's drawn balance | Establishment fee at drawdown, interest monthly or capitalised | Any future GST credit a lender has not agreed to recognise |
| Holding costs | Rates notice, insurer, state revenue office, and your program | Recurring across the project life | Loan interest, kept visible on the finance line |
| Selling and marketing | The agency agreement; the marketing budget | Campaign spend early, commission at settlement | GST treatment of the sale itself |
Acquisition: Land and the Costs Attached to It
In South Australia, RevenueSA publishes a nine-band conveyance duty schedule. As at October 2026 the top band is $21,330 plus $5.50 per $100 over $500,000. Duty currently applies only to residential and primary production land, which includes vacant land carrying an urban residential land use code: a narrower base than in most states. Because the top band begins at $500,000, the marginal rate steps up early in the price range. No single national "stamp duty percentage" is given here, because none exists. Conveyancing, title searches and pre-commitment due diligence reports belong in this category too.
Everything here is land-attached. The formula RLV = GRV − non-land development costs − target profit only holds if these costs stay on the land side. Roll transfer duty into "development costs" and you have deducted the site twice.
There is a circularity worth naming: transfer duty, land-related interest and any margin scheme calculation all depend on the price you pay, so the land price is an input to costs that themselves determine what you can afford. Real models iterate; they do not subtract once.
Statutory Fees and Contributions
Application fees are usually two charges, not one: a lodgement fee per application, scaled to total development cost, and a separate assessment fee per consent. PlanSA's published schedule sets performance-assessed planning assessment at $289 or 0.125% of total development cost up to a cap, whichever is greater. Building consent, land division and Certificate of Approval fees are separate consents with separate fees.
Contributions are larger and later-dated. Under section 198 of the Planning, Development and Infrastructure Act 2016, a division creating 20 or fewer allotments may pay a cash contribution in lieu of setting aside open space, at a prescribed per-allotment rate that differs across the state, paid into the Planning and Development Fund. Utility headworks sit here too.
Timing is split: lodgement now, assessment fees on invoice, contributions at the back end as a precondition to titles.
Professional and Consultant Fees
Design and approval: architect or building designer, town planner, surveyor, civil, structural, hydraulic and geotechnical engineers, plus whatever specialists the site drags in — arborist, heritage, acoustic, traffic, contamination, ESD — and the certifier. Project-side: development manager, quantity surveyor, superintendent, solicitor, accountant, tax adviser, insurance broker.
The specification error that matters is the denominator. Fees are quoted both against construction cost and against total development cost, and the published Australian benchmark is generally expressed against total development cost. Apply the same percentage to build cost alone and you understate the line substantially. The consultant's fee proposal is the evidence; a percentage is a benchmark, not a quote.
Construction and Civil Works
The contract sum and its preliminaries. Demolition. Earthworks and cut and fill, the line that most reliably exceeds its desktop estimate once rock, unsuitable fill or a high water table appears. Retaining and remediation. Civil works: roads, drainage, stormwater detention, crossovers, services trenching. Landscaping and external works. The evidence is a quantity surveyor's estimate or a tendered price, not a square-metre rule of thumb.
Two allowances belong beside this line but not inside it. Escalation prices the passage of time between pricing and delivery; contingency prices the unknown. Merge them and you lose the ability to explain either.
Contingency
Contingency is a budgeting convention, not a regulated figure: there is no legislated rate and it does not vary by state. What it should track is remaining design uncertainty. At concept the design is a sketch and the cost plan is built from rates, so a double-digit allowance is honest. Once you hold a tendered or fixed-price contract the range narrows sharply, because most pricing risk has resolved into the contract sum. Lenders read the allowance as a signal: an independent quantity surveyor usually reviews it, and contingency consumed faster than the build progresses suggests the budget was tight from the start.
Finance and Holding Costs
Interest runs across the whole period you hold debt, starting when you settle rather than when you build. Add establishment fees, line fees, and the QS, valuation and reporting fees the lender requires. Interest is a function of the amount drawn, the rate and the time; the third is the one most developers accept rather than manage.
Holding costs are the category most often underestimated, because they are modelled against a program that assumes everything runs to time. They cover council rates, land tax where it applies, insurance, utilities, security, fencing and site maintenance. Land tax is a state tax with its own thresholds and aggregation rules, so confirm your entity's position with the state revenue office rather than importing a figure from another portfolio.
Both lines are driven by duration, not activity. Three extra months in planning is not a scheduling inconvenience; it is a quantified outflow. Model your release price against the cash actually available at settlement unless the facility documents expressly recognise a future GST credit.
Selling and Marketing
Agent commission, project marketing, photography and renders, signage, display suite, strata or owner-corporation establishment, contract legal work, settlement costs. Off-the-plan campaigns front-load the spend: marketing cost lands long before the settlement that pays the commission.
GST: A Cash-Flow and Pricing Issue, Not a Cost Line
GST on a property sale is normally one-eleventh of the price. Under the GST margin scheme it is one-eleventh of the margin instead, which is why developers care and why it is usually misunderstood.
Under the ATO's consideration method, the margin is the sale price minus the original purchase price, and that purchase price deliberately excludes development costs, legal fees, option fees, stamp duty and other related purchase expenses. Settlement adjustments for rates, land tax and rent do form part of it. Those two rules are easy to reverse, and reversing them changes the number. Eligibility turns on how the property was acquired, not on what the sale contract says; the parties must agree in writing on or before settlement, and a buyer cannot claim a GST credit on a margin-scheme purchase.
Two consequences for a feasibility. State the GST basis of your gross realisation value explicitly, because a price quoted gross of GST overstates the cash that arrives. And the 7% withholding on residential settlements is a settlement proxy, not the final liability; the difference reconciles through the BAS, and that gap belongs in the cash flow as a working capital requirement.
An Illustrative Cost Stack, Reconciled
The following is an illustrative example only — synthetic figures built to show the structure, not a quote, valuation or current fee schedule for any site. It assumes a small South Australian infill project of three townhouses, all amounts GST-exclusive unless stated.
| Item | Amount |
|---|---|
| Gross realisation value (GRV) | $3,000,000 |
| — Construction (including contingency) | $1,500,000 |
| — Professional fees | $120,000 |
| — Statutory fees and contributions | $80,000 |
| — Finance and holding costs | $150,000 |
| — Selling and marketing | $150,000 |
| Non-land development costs | $2,000,000 |
| Target profit | $400,000 |
| Residual land value (land price ceiling) | $600,000 |
At a $600,000 land price: total development cost $2,600,000, profit $400,000, margin on cost 15.38% ($400,000 ÷ $2,600,000), margin on revenue 13.33% ($400,000 ÷ $3,000,000). Different denominators produce different percentages, which is why a margin quoted without its base is meaningless. The reconciliation holds only because the land price sits outside the $2,000,000.
South Australia: Current Statutory References
These rates are state-specific and index annually, so they are listed with sources rather than mixed into the illustration above.
- Transfer duty — RevenueSA conveyance duty schedule; top band $21,330 plus $5.50 per $100 over $500,000; applies to residential and primary production land, including vacant residential land (revenuesa.sa.gov.au, accessed October 2026).
- Planning and building fees — set by a Ministerial fees notice in the Government Gazette and indexed each 1 July. PlanSA's application fees page lists banded lodgement fees by total development cost, and performance-assessed planning assessment at $289 or 0.125% of total development cost up to a cap, whichever is greater (plan.sa.gov.au, accessed October 2026 — confirm against the current Gazette fees notice, since this page can lag the gazetted rate).
- Open space contribution — PDI Act 2016 s.198; divisions of 20 or fewer allotments may pay a prescribed per-allotment contribution in lieu of open space, at Certificate of Approval stage.
- SA Water augmentation, FY2026-27 — Greater Adelaide infill $8,034 per additional connection ($4,017 water, $4,017 wastewater); greenfield $10,712, payable before SA Water clears titles (SA Water augmentation).
- CITB levy — 0.25% of estimated project value; for approvals or commencement after 1 January 2025, above $100,000 excluding GST (CITB).
Check the current Gazette fees notice and each authority's own schedule before you commit, because these figures are indexed and band thresholds move.
Cyberate PM, part of the DDDI Group, works on the owner's side of this problem: planning and yield assessment, cost and revenue modelling, and sensitivity testing, with the cost stack built line by line against current South Australian fees and charges. Their feasibility service is where the checklist above gets built for a specific parcel. This is a related-party service of the DDDI Group, not an independent recommendation.
Where the Group's 40+ Line-Item Model Fits
Cyberate PM publicly describes a feasibility model built on 40+ cost line items with quarterly cash flow, margin on cost, return on equity and ±8% sale price sensitivity testing. The DDDI Group's own services page presents a condensed extract of the same structure across acquisition, statutory, construction, finance and holding, and sales.
To be unambiguous about those pages: the figures displayed are synthetic, illustrative examples of the method, generated and rounded. They are not real project financial data, not group project results, and not a quote or current fee schedule. What transfers is the structure: enough separate lines that each can be given an evidence owner, a timing and a scope boundary. The feasibility guide covers the decision framework, and the feasibility template sets out the model's layout.
Once the stack is complete, two questions follow: what land price it supports, which is a residual land value calculation, and what return it produces, measured by margin on cost. Both turn on costs that will move, which is what sensitivity analysis tests.
Frequently Asked Questions
Should the land purchase price be listed as a development cost?
Keep it separate. The residual land value formula deducts non-land development costs and target profit from gross realisation to reach the land price ceiling. If the purchase price is also inside the cost stack, the site is deducted twice.
Is GST a development cost?
No. It is a revenue and cash-flow treatment. Under the margin scheme the GST depends on your acquisition history and original purchase price, not your development spend.
How much contingency should a feasibility carry?
There is no regulated rate. Size it against how resolved your design is: higher while the design is a sketch and no builder is appointed, lower once you hold a fixed-price contract.
Why is my professional fee percentage double someone else's?
Almost always the denominator. The same percentage against construction cost and against total development cost produces materially different money.
Can I reuse the stamp duty figure from my last project?
Only as a starting point. Transfer duty is state-specific, scales with dutiable value rather than price alone, and may include a foreign ownership surcharge.