Gross Development Value is the total resale value of the completed scheme: units multiplied by net internal area multiplied by achievable resale price per sqft. For mixed-use schemes the commercial element is capitalised on yield instead of priced per sqft.
Indicative only. The workbench applies the same arithmetic a chartered surveyor uses but it does not run a daylight study, a contamination test, or a multi-phase cash flow. Use it for pre-bid sense-checks. For a Red Book valuation you need an MRICS valuer.
Yes. The s106 / CIL / BNG per-unit field on the inputs rail is where you enter the planning cost overlay. CIL is per sqm of net additional floorspace; convert to per-unit by multiplying by GIA in sqm.
Not yet. PDF export is planned for v2. For now the workbench output is on-screen only. Copy the residual figures into your lender pack.
Each regional rate is a BCIS £/sqm figure as reprinted in a named council viability study, and carries that study's BCIS data date: the newest is Cardiff (BCIS figures taken 25 July 2026), the oldest Tees Valley (BCIS data last updated 16 November 2024). BCIS itself is subscription-only. The BCIS build cost page lists every source and date.
PoC divides profit by cost; PoGDV divides profit by GDV. Both are valid; they serve different audiences. Planning authorities apply PPG-Viability's 15 to 20 percent PoGDV range (17.5 percent midpoint); lenders reference 20 percent PoC.
Green is reserved for the council-tax / stamp-duty sibling cluster across our portfolio. The GDV palette is dark slate base, blueprint cyan (inputs), amber (residual outputs), magenta (abort cells). Avoiding green keeps the visual identity distinct.
Default 5 percent SDLT-on-land rate, reflecting bare land with consent for residential development. Override the field if your site is genuinely non-residential at completion (commercial use, mixed-use, six-or-more-dwellings rule).