Feasibility Quick-Check
High-level GFA, revenue, cost and margin in 60 seconds — before you commission a single drawing.
Typical apartment efficiency is 80–85%.
Margin on cost
38.85%
Profit: $5.68M
About this calculator
This development feasibility quick-check calculator gives you a 60-second view of whether an Australian residential development site is worth pursuing. It converts a handful of high-level assumptions — site area, FSR or density, NSA efficiency, build rate and end sale price — into GFA, revenue, total cost and developer margin.
How the quick-check is calculated
GFA is derived from site area × FSR (or dwelling yield × average dwelling GFA). NSA is GFA × the efficiency ratio you set. Revenue is NSA × the average sale rate, less GST under the margin scheme and selling costs. Total cost stacks land, construction (GFA × build rate), professional fees, contingency, council contributions and finance. Margin is shown both on cost and on revenue.
Assumptions and limitations
- Single-product feasibility — mixed-use or staged projects need a full feasibility model.
- No cash-flow timing — finance is approximated as a % of cost.
- Selling costs and GST under the margin scheme are baked in at industry-standard rates.
- No allowance for site-specific abnormals (contamination, services upgrades, heritage).
When to use it
Use the quick-check before commissioning a town planner, architect or QS, when screening listings on a real-estate portal, or as a sanity check on a broker’s pitch deck. Once a site looks promising, move to the Residual Land Value calculator to back-solve the maximum land price, then to the IRR & Equity Multiple calculator once you’ve modelled a cash-flow schedule.
Frequently asked questions
- What is a development feasibility quick-check?
- A high-level back-of-envelope test that takes a few key assumptions — site area, allowable density or FSR, NSA efficiency, build rate and end sale price — and tells you whether a project has any chance of stacking up before you spend money on a town planner, architect or QS.
- What is the difference between GFA and NSA?
- GFA (gross floor area) is the total building area measured to the outside of external walls; it is what the planning rules limit via FSR. NSA (net sellable area) is the saleable area inside each apartment or townhouse — typically 75–85% of GFA after stripping out lobbies, lifts, stairs, services and walls.
- What FSR or density should I assume?
- Use the FSR or density permitted by the current planning controls for the site — these are published in the LEP/DCP in NSW, the planning scheme in QLD, and the planning scheme overlay in VIC. Do not assume an uplift unless you have a planning opinion that supports it.
- What build rate per m² should I use?
- In 2026 Australian residential build rates broadly range from $2,800–$3,500/m² GFA for low-rise townhouses, $3,500–$4,500/m² for 3–5 storey walk-up apartments, and $4,500–$6,500+/m² for mid-rise and high-rise with basement parking. Always confirm with a current QS for the specific market and site.
- What margin makes a project feasible?
- Most Australian banks require a minimum 20% margin on total development cost before they will provide construction finance. A margin of 15% or below typically means you need to either reduce the land price (use our Residual Land Value calculator) or revisit the product mix.
Estimates are indicative only and intended as a starting point. Actual figures depend on lender policy, market conditions, professional fees, taxes and other costs. Always confirm with a licensed broker, accountant, valuer or solicitor before acting.