Feasibility and purchase decisions
Development profit calculation for a Victorian subdivision
Development profit calculation starts with the whole property and a defined exit. Reconcile acquisition, construction, holding, selling and applicable tax costs before comparing the remaining profit with the cash required. For land already owned, also compare the development outcome with keeping or selling the existing property. These are appraisal methods for testing assumptions, not a forecast of your return.
Prepared by Joey Don · Co-Founder & CEO, PremiumReaContent updated
Questions to resolve before committing
Read the answer with its assumptions and source notes. A planning rule can establish an assessment pathway; it cannot establish the price, funding or outcome for your property.
How do I calculate profit on a buy, retain and build project?
Start with the combined sale proceeds and deduct the complete project costs, using one consistent GST basis. Acquisition, duty, professional work, renovation, new construction, site works, holding, finance and selling costs all need a place. Keep income tax outside a clearly labelled pre-income-tax result until reviewed. A rear dwelling that appears profitable on its own does not establish that buying and developing the whole property works.
Why is the building quote not the total development cost?
A building quote prices its stated construction scope, while the feasibility must cover every step needed to reach the selected exit. Read the exclusions and place services, subdivision work, professional fees, holding costs and selling costs into separate lines where appropriate. An allowance inside the contract should not also appear as an additional full cost outside it. Reconcile scope before comparing totals from different suppliers.
What belongs in the denominator of a cash-on-cash return?
Use the owner cash actually required under the stated model, and explain its timing convention. A simplified cumulative measure includes acquisition and works funded by the owner, plus owner-paid interest, holding and pre-sale expenses. Using only the initial deposit can overstate the percentage. If there are interim receipts or recycled contributions, show the cash schedule as well, because one cumulative denominator cannot describe every financing pattern.
Is interest counted twice if it reduces profit and increases cash invested?
No: the two appearances answer different questions. Interest is an expense when calculating profit, and owner-funded interest is also money the owner must contribute. The error would be deducting the same interest twice within the profit calculation, or funding it both with owner cash and capitalised debt without an offset. Label each line by economic cost and funding source so the two views reconcile.
Should repayment of the loan principal reduce development profit?
Loan principal repayment belongs in the cash reconciliation, not as another development expense after the purchase and construction costs have already been counted. Borrowing finances those costs; repaying it settles the financing balance. Interest and relevant loan fees are separate expenses. Show sale receipts, settlement deductions, debt repayment and tax cash movements to explain how project profit becomes cash returned to the owner.
Why is the cash returned after settlement larger than the profit?
Returned cash usually includes recovery of the owner’s original contributions as well as any profit. Under a simple model with no interim distributions, cash returned equals cash contributed plus profit after the modelled deductions. A settlement statement may show a different interim amount because tax reconciliation or unpaid costs remain. Compare like-for-like dates and liabilities before treating money in the bank as freely available surplus.
If I already own the land, can I enter the land cost as zero?
Zero may describe the additional purchase cash needed today, but it does not measure the land’s economic contribution. Compare the existing property’s evidenced value with the completed outcome, including the retained front home on its smaller lot. Keep this opportunity-value comparison separate from historical acquisition records and tax calculations. Otherwise, a result described as development profit can include value that was already present in the land.
Can I judge the front and rear dwellings as separate profit centres?
Only after explaining how shared costs and land value have been treated. A working spreadsheet may assign acquisition to the front dwelling and construction to the rear for reconciliation convenience. That does not make the rear land free, or establish independent market values or tax allocations. Review the whole-project result first, then use the separate columns to locate cost drivers and compare clearly defined alternatives.
What is the difference between profit margin, return on cost and cash return?
They divide the same stated profit by different bases. Profit margin uses revenue, return on cost uses the defined total cost, and cash-on-cash return uses the defined owner cash contribution. Debt can change cash return without improving the underlying sale price or construction outcome. State the period, GST and income-tax basis beside each metric, and compare projects only after aligning all of those definitions.
Is dividing a project return by its duration the same as IRR?
No. Simple annualisation scales a period return by time; it does not use the dates of individual contributions and receipts. IRR needs a dated cash-flow series and has its own interpretation limits. Neither figure proves the project can be repeated or financed on the same terms. For an initial purchase discussion, show the actual project-period result, expected cash timing and downside before adding an annualised comparison.
Turn the answer into a buying decision
- 1
Define the property and exit
Record what is being bought, retained, built and sold. Use the proposed lot boundaries and dwelling specifications for each sale assumption.
- 2
Build one complete cost register
Separate paid costs, current quotes, allowances and unresolved items. State the GST treatment and payment timing beside each line.
- 3
Reconcile profit and cash
Calculate total profit, owner contributions, debt repayment and cash returned separately. Make the opening and closing balances agree.
- 4
Compare alternatives
Test the development against an evidenced no-development option and downside scenarios before interpreting any return percentage.
Evidence to request
- Proposed lot and dwelling schedule
- Separate supported sale assumptions for retained and new dwellings
- Acquisition, works, holding, sale and tax cost register
- Cash reconciliation with debt shown separately
- Existing-land opportunity value and no-development comparison
Bring the address and the assumptions
A clear brief includes the title, a preliminary concept, the intended exit and the available cash. PremiumRea can help organise the acquisition checks and questions for the planner, surveyor, builder, accountant and licensed credit professional.
Sources and scope
Government references support the specific rules attached to each answer. Feasibility methods explain how to organise a calculation; they are not prescribed tax treatment or a prediction of a project result.
Connect the next decision
Keep the questions with your feasibility file
Download the same questions, answers, stable page links and source notes for reference. The source date records when a reference was checked, not an approval or review of your property.
Original explanations are available under CC BY 4.0 with attribution to PremiumRea and a link to the relevant page. Third-party government material retains its own terms; this permission does not relicense it. CC BY 4.0
General information for property acquisition and feasibility. Confirm property-specific planning, title, legal, tax and lending matters with the relevant qualified professional. A scenario result is not an achieved return.