Assess the Feasibility of Your Property Development
Feasibility brings together what a site could accommodate, what it might cost to deliver and what it could be worth. Use the indicative appraisal calculator below and the checklist of risks to investigate.
Development Appraisal Calculator
Model GDV, cost, profit and residual land value. Figures are indicative, not a formal valuation.
Inputs
Calculations use explicit formulas. Edit any input to see results update instantly and compare scenarios.
Cost Breakdown
Site assessment and development potential
Start with what the site can realistically accommodate: its area, shape, access, topography, neighbours and planning context. Residential, commercial or mixed uses may each be possible, with different values and risks.
Costs to allow for
A credible appraisal goes beyond the build cost per square metre.
- Construction cost assumptions and specification
- Professional fees and surveys
- Infrastructure and abnormal costs (e.g. ground, drainage, utilities)
- Statutory costs such as CIL and Section 106
- Contingency
- Finance, programme and holding costs
- Sales and marketing
Values, sensitivity and risk
Sales values or rental assumptions should be evidenced with comparable data. Test how profit changes if values fall or costs rise — a scheme that only works under optimistic assumptions carries significant risk.
How the calculator works
The calculator uses explicit, published formulas — not AI arithmetic. Total development cost = land + construction + fees + contingency + finance + marketing + statutory costs. Profit = GDV − total development cost. Residual land value = GDV − all costs except land − target profit. Change any input and compare scenarios.
What this is not
Outputs are indicative only. They are not a formal valuation (such as a RICS Red Book valuation), a guaranteed profit forecast or an investment recommendation.
Frequently asked questions
This page provides general, preliminary information. It is not a planning decision, formal valuation or professional appointment. Appropriate checks and current planning information may be required. Last reviewed 2026-06-01.