Estimate whether a residential development scheme is commercially viable using GDV, build costs, land cost, SDLT, professional fees, contingency, finance, sales costs and target profit.
This is a high-level feasibility tool, not a formal valuation. It uses simplified assumptions and should not replace a professional residual appraisal, cost plan, valuation, planning review or finance advice.
The calculator compares the estimated completed value of the scheme against the main development costs. In feasibility mode, it shows the estimated profit after entering a land cost. In residual mode, it estimates the maximum land value after allowing for a target profit.
Use this when you already have an asking price or assumed land cost. The calculator estimates whether enough profit remains after development costs, finance, fees, contingency and obligations.
Use this when you want to know what the land may be worth after deducting build costs, fees, finance, planning obligations and a target developer profit from GDV.
| Profit on GDV | Verdict | Typical interpretation |
|---|---|---|
| Below 15% | Unviable / high risk | May be difficult to fund unless risk is unusually low or assumptions improve. |
| 15%–18% | Marginal | May need careful review, stronger evidence, lower land cost or reduced risk. |
| 18%–22% | Healthy | Often closer to a standard benchmark for many private residential development appraisals. |
| Above 22% | Strong | Potentially more resilient, but still dependent on costs, sales evidence and planning risk. |
A calculator is useful for early testing, but live development decisions need site-specific cost evidence, sales comparables, planning review, abnormal cost testing and a clear masterplan.
It is an early-stage tool that compares GDV against land cost, build cost, fees, finance, planning obligations and target profit to estimate whether a development may be commercially viable.
Residual land value is the estimated amount left for land after deducting development costs, finance, planning obligations, contingency and target profit from GDV.
Many early residential appraisals test profit around 15–20% of GDV, although the correct margin depends on risk, funding, tenure, delivery route and market conditions.
Yes. This calculator includes an indicative SDLT calculation for non-residential or land purchases using the standard banded approach.
Development finance cost depends on both the interest rate and the length of time funds are used. A longer project duration can significantly reduce feasibility.
No. It is a high-level estimate only. A professional appraisal should use site-specific layouts, cost planning, market evidence, planning review, finance assumptions and risk assessment.
Profit on GDV compares the estimated developer profit to the completed development value. It is a common way to sense-check whether a scheme has enough margin for risk.
Profit on cost compares estimated profit to total development cost. It helps show how much return the scheme may generate against the money spent.
