GDV.calculator

Disclaimer

The output of this workbench is indicative only. It is not a RICS Red Book valuation, not a regulated financial promotion, not legal or tax advice, and not a lender decision-in-principle. Use it for pre-bid sense-checks; commission a chartered surveyor before commiting a bid.

What this is

  • A free residual development appraisal workbench.
  • Inputs follow RICS Red Book conventions and NPPF Dec-2025 framing.
  • Build-cost rates from BCIS Q2-2026.
  • Source-of-record links on every page.

What this is not

  • Not a RICS Red Book valuation. No MRICS valuer has signed off the working numbers on this page.
  • Not a lender decision-in-principle. Senior debt sizing is indicative.
  • Not financial advice. Not regulated by the FCA.
  • Not legal or tax advice. SDLT, LBTT, LTT and VAT mechanics are working approximations.
  • Not a daylight or BRE 209 study. Specialist tool needed.

Limitation of liability

You use the workbench at your own risk. Digital Signet, its principals and reviewers accept no liability for decisions made on the basis of the output. Before committing a bid, retain a chartered surveyor, a regulated finance broker and a property tax adviser.

When to commission a chartered surveyor

  • Any deal of material value to your portfolio.
  • Any lender requesting a Red Book valuation.
  • Any planning viability submission.
  • Any disposal or acquisition needing audit-grade evidence.
RICS Valuation Global Standards (Red Book)· Effective 31 Jan 2025Appraisal model reviewed by Oliver Wakefield-Smith (data integrity) with chartered-surveyor (MRICS) and CTA tax review. No affiliate links.