What is Gross Development Value?
Gross Development Value (GDV) is the total market value of a completed development — the sum of all individual unit values once the project is built, finished, and ready for sale or letting. It is the single most important number in any development appraisal because it determines the revenue side of the equation.
GDV directly affects every key lending ratio: LTGDV, profit on cost, and profit on GDV. An accurate GDV estimate is therefore critical — both for the developer's investment decision and for securing development finance.
How to calculate GDV
The standard approach to calculating GDV for residential development in the UK involves comparable evidence analysis:
- Step 1: Identify comparable sales — completed transactions for similar properties in the same area, ideally within 0.5 miles and 12 months.
- Step 2: Calculate £/sqft — divide the sale price by the gross internal area to get a price per square foot for each comparable.
- Step 3: Adjust for differences — account for quality of finish, aspect, floor level, parking, outdoor space, and market movement since the comparable sold.
- Step 4: Apply to your scheme — multiply the appropriate £/sqft rate by each unit's proposed size to estimate individual unit values.
- Step 5: Sum all units — the total is your GDV.
Sources of comparable evidence
- Land Registry — actual transaction prices (1–3 month lag for registration).
- Rightmove / Zoopla / OnTheMarket — asking prices and sold prices for current market context.
- New build developments nearby — the most relevant comparables if available.
- RICS valuation — a formal Red Book valuation from a qualified surveyor carries the most weight with lenders.
Common GDV mistakes
- Using asking prices instead of achieved prices — asking prices are aspirational; lenders want evidence of completed sales.
- Cherry-picking comparables — using only the highest sales while ignoring lower ones creates an unrealistic picture.
- Ignoring market conditions — comparables from a rising market may not reflect current conditions.
- Overcounting — including garages, balconies, or commercial space at residential rates.
- Specification mismatch — comparing a basic refurbishment to a premium new build development.
GDV for commercial and mixed-use schemes
For commercial elements (offices, retail, restaurants), GDV is typically calculated using the investment method: estimated annual rental income divided by an appropriate yield (capitalisation rate). For mixed-use schemes, each element — residential units, commercial space, parking — is valued separately and summed.
Frequently asked questions
Should I get a formal valuation before applying for finance?
Not necessarily — the lender will commission their own valuation as part of the application process. However, having robust comparable evidence in your credit paper demonstrates that your GDV assumption is grounded in reality, not optimism. Assesr automatically benchmarks your GDV against comparable transaction data as part of the credit paper.