Project Carter
Development Feasibility (GRV) Calculator
Take a development from approval to settled sales. Start with the cost to reach DA, then add the post-DA consultants, the construction by dwelling type, the council and finance costs, and the gross realisation on sale. The tool has a 2026 construction cost estimator for a design-and-construct or a trade-contract build, estimates GST under the margin scheme, and reports expected profit, profit on cost, cash-on-cash return and a worst-case scenario. The numbers update live, and you can take away a one-page PDF. It is an estimate to help you think, not financial, tax or planning advice.
Report
Shown on the PDF and used to name the report if you save it to your account.
Cost to reach DA
This calculator picks up where the Development Site (DA) calculator leaves off. Run that first for a full build-up of land, buying costs, DA consultants, council fees and holding costs, then bring the total across.
The "Total cost to DA" from the DA calculator: land price plus every cost of getting to development consent, including interest through the DA period.
The price paid for the land only. Used to estimate GST under the margin scheme. It is not added to costs again; the DA total above already includes it.
Building contract
Under a design & construct contract the builder carries and prices the architect's documentation to CC, the structural and civil, hydraulic, mechanical / electrical / fire, facade and ESD design, the building surveyor / certifier, the construction certificate / permit fee, the long service levy, and the contract works and public liability insurance. Those lines are struck out below and left out of your totals; they sit inside the contract sum you enter per dwelling type. You still carry the set-out surveyor, the superintendent, the QS progress inspections, the infrastructure charges and contributions, and your own project management. Enter your own professional indemnity or latent-defects cover under "Other holding cost".
Post-DA consultants & certification
Documentation from consent to construction certificate, and the consultants who see the build through. Enter only what applies.
Council & statutory (post-DA)
Council or state infrastructure charges, usually payable at or before construction certificate. This is where they belong, not in the DA cost.
Payable in most states on building work over a threshold, for example 0.25% of the cost of works in NSW, paid before the certificate issues.
Damage and civil-works bonds are usually refundable, but hold cash. Enter only the part you expect to spend.
Construction
Construction cost estimator. Pick the state, type and quality and it fills each dwelling type's build cost from a 2026 rate applied to its floor area. Editing a build cost switches the estimator off for all of them; clear them to bring it back.
Total area of basement or undercroft parking across the project. Leave blank for on-grade parking.
Set the state, type and quality to see an indicative rate.
Indicative only, compiled from Australian quantity surveyor cost guides (Rawlinsons, Altus, AIQS) projected to 2026. Rates are per m² of gross floor area and include builder preliminaries and margin, but exclude GST, land, demolition, site remediation, external infrastructure, council contributions, professional fees and finance. Basement parking is rated per m² and costs more for deep or multi-level structures. A real cost plan from a quantity surveyor will differ. Not a quote.
One card per floor plan. Enter how many are built to that plan, its floor area, the build cost and the sale price per dwelling. Add a card for each different plan. Up to 12 types. Each card also shows the construction-only cost per dwelling and a blended land + build cost per dwelling, where the land and cost to DA is spread across the types by floor-area share. Enter all costs exclusive of GST.
Filled from the basement area in the estimator. Edit to pin.
Added on top of the dwelling and basement build costs. The estimator's rate already includes builder preliminaries and margin, so leave this at 0 when the build costs come from the estimator. Use it only when you have entered bare trade or construction costs.
Enter here only if it is outside the building contract.
Finance & holding (post-DA)
From DA to the last settlement. The holding costs below are charged for this period.
The approved loan limit, used as the base for line and commitment fees below. Leave blank to use the debt required instead.
One row per charge, since interest, line fee, establishment and admin fees each sit on a different base. Enter a rate, pick what it applies to, and say whether it is one-off or per annum. A per-annum rate on the debt required is treated as the interest rate (BBSY + margin, or a fixed rate) and is run through a drawdown: debt starts low, equity is spent first, and the balance builds to its peak near the end, so interest is charged on the debt actually outstanding month by month and capitalised, not on the peak for the whole period. A per-annum rate on the facility limit is a line or commitment fee, charged on the limit for the whole period. One-off rates on the facility limit or total project cost are establishment and admin fees. Rates on the debt required or total project cost are worked out before finance to avoid circularity.
There is no rental income once the site is under construction, so no holding income is netted off.
Contingency & management
Applied to the post-DA consultants, statutory fees and construction. Not to the DA total or finance. Defaults to 10%; change or clear it as needed.
GST on sale
Sale prices are entered per dwelling type in the construction section above.
Margin scheme: GST is roughly (gross realisation − land price) ÷ 11. Input credits on construction are claimed separately and are not modelled here.
Enter your accountant's figure to use it instead of the estimate. **Check with your accountant to confirm your circumstance.**
Funding & scenarios
The "Cash (equity) required" figure from the DA calculator: the part of the cost to DA you funded yourself rather than with a land loan. It counts as contributed capital here.
Further equity you put in from DA through to settlement, on top of the DA-stage equity above. The two together are your total contributed capital; the rest of the project cost is the debt required, and the cash-on-cash return is measured on the total.
- Post-DA consultants & certification
- —
- Council & statutory
- —
- Construction (incl. margin & extras)
- —
- Contingency
- —
- Finance & holding
- —
- of which interest (drawn & capitalised)
- —
- Development management
- —
- Total project cost
- —
- Cost per dwelling
- —
- Selling costs
- —
- GST (margin scheme)
- —
- Net sales proceeds
- —
- Expected profit
- —
- Profit per dwelling
- —
- Profit on cost
- —
- Profit margin on GRV
- —
- Total equity contributed
- —
- Debt required
- —
- Average debt drawn
- —
- Peak debt (end of period)
- —
- Cash-on-cash return
- —
- Profit - worst case
- —
- Profit on cost - worst case
- —
Your feasibility
Figures are part-hidden. Unlock the full numbers and one-page PDF below.
Project Carter is sent your figures for an assessment only if you request one.
What-if scenarios
| Scenario | Change | New value | Effect on profit |
|---|---|---|---|
| Enter a gross realisation and costs to see the scenarios. | |||
Get your feasibility summary
The page builds a one-page PDF of your figures, the feasibility result and the worst-case scenario. A copy is sent to Project Carter so we can follow up if you'd like.
Done. Your PDF has downloaded. If it didn't, . Project Carter has your figures and will be in touch if you asked for a follow-up.
How the numbers work
- Cost to reach DA. Bring the "Total cost to DA" across from the DA calculator. That figure already includes the land, the buying costs, the DA consultants, the council fees and the holding and interest to consent, so this page does not ask for them again. The land price is entered once more on its own, only to estimate GST under the margin scheme.
- Building contract. Under design & construct the architect's documentation to CC, the structural and civil, hydraulic, services, facade and ESD design, the building surveyor / certifier, the construction certificate / permit fee, the long service levy, and the contract works and public liability insurance all sit inside the contract sum, so those lines are struck out and left out of your totals. Under a construct-only build every line is a developer cost and a builder's margin applies. Either way, construction is entered per dwelling type.
- Dwelling types. One card per floor plan: how many are built to it, its floor area, the build cost and the sale price per dwelling. Each card also shows a construction-only cost per dwelling (build cost plus its share of basement and builder's margin) and a blended land + build cost per dwelling, which adds that type's share of the land and cost to DA, spread across the types by floor-area (GFA × count) share. The construction estimator fills each type's build cost from a 2026 rate per m² for the state, type and quality chosen (the rate includes builder preliminaries and margin). Editing any build cost pins your own numbers and switches the estimator off; clear them to bring it back.
- Builder's margin is added on top of the dwelling and basement build costs. Leave it at 0 when the costs come from the estimator, which already includes it; use it only for bare trade costs.
- Contingency is your percentage applied to the post-DA consultants, the statutory fees and the construction. It defaults to 10% and can be changed or cleared. It is not applied to the DA total or to finance.
- Finance charges. Each row is a rate on a chosen base: the debt required, the facility limit (or the debt required if no limit is entered), the total project cost, or a flat dollar amount. One-off rows are charged once; per-annum rows are charged over the construction and settlement period (months ÷ 12). A per-annum rate on the debt required is the interest rate (BBSY plus margin, or a fixed rate if you have one) and is run through a drawdown rather than charged flat: costs are assumed to draw on a smooth S-curve through the period, your equity is spent before any debt, and interest accrues on the balance outstanding each month and is capitalised. That is why the interest line sits well below peak debt times the rate times the term, and why the results also show the average debt drawn and the peak debt at the end. Rates on the debt required or total project cost use the pre-finance total, so a finance charge is never levied on the finance charges themselves. Holding costs are entered per year and charged for the same period. There is no rental income during construction.
- GST. All cost inputs are entered exclusive of GST. Input tax credits on construction and consultants are claimed separately and are not shown here. Only GST on the sale is modelled, via the margin scheme or your accountant's override.
- Gross realisation is the sum of each type's sale price times its count. Selling costs are each type's price times its selling-cost percentage, times its count. GST under the margin scheme is estimated as (gross realisation − land price) ÷ 11; choose "no GST" for input-taxed stock, or enter your accountant's figure as an override. Input tax credits on construction are claimed separately and are not netted here.
- Total project cost is the DA total plus the post-DA consultants, statutory fees, construction, contingency, finance and holding, and development management. Net sales proceeds is gross realisation less selling costs and GST. Expected profit is net sales proceeds less total project cost.
- Profit on cost is expected profit ÷ total project cost. Profit margin on GRV is expected profit ÷ gross realisation. Total equity contributed is the equity invested to reach DA plus the additional cash contribution. Debt required is total project cost less that total equity, and cash-on-cash return is expected profit ÷ the total equity contributed.
- What-if scenarios. The two levers drop every sale price by one percentage and lift the consultant and construction costs (and the contingency on them) by the other. The worst case applies both at once. This is a sensitivity check, not a forecast.
- This is a feasibility estimate built from the figures entered. It excludes changes in interest rates and the sales program, presales conditions, staging, tax other than GST, and anything specific to a site or a funder. It is not financial, tax or planning advice. Speak to Project Carter, your accountant and a licensed adviser before acting.
Common questions
What's the difference between Design & Construct and Construct-only?
Under Design & Construct, the architect's documentation to CC, structural and civil, hydraulic, services, facade and ESD design, the building surveyor or certifier, the construction certificate or permit fee, the long service levy, and contract works and public liability insurance all sit inside the builder's contract sum, so those lines are struck out and left out of your totals. Under construct-only, every line is a developer cost and a builder's margin applies.
What builder's margin should I use?
Leave it at 0 when construction costs come from the built-in estimator, since that rate already includes builder preliminaries and margin. Only add a margin percentage when you're entering bare trade costs.
How is GST calculated on the sale?
The default is a margin-scheme estimate: gross realisation less the land price, divided by 11. Switch to "no GST" for input-taxed stock, or override it with your accountant's figure. Input tax credits on construction are claimed separately and are not netted here.
What contingency percentage is typical for a development feasibility?
This calculator defaults to 10%, applied to the post-DA consultants, statutory fees and construction. It's editable, and it is not applied to the DA total or to finance charges.
How does the finance drawdown work in this calculator?
Costs are assumed to draw on a smooth S-curve through the construction period, your equity is spent before any debt, and interest accrues monthly on the balance outstanding and is capitalised. Results show both the average debt drawn and the peak debt at the end of the period.
Is this a profit forecast?
No. It's a feasibility estimate built from the figures you enter, plus a sensitivity check on sale prices and costs. It excludes changes in interest rates, the sales program, presales conditions and staging, and it is not financial, tax or planning advice.