Development Contingency Percentage

Contingency by scheme risk: 5 percent on simple new build, 7.5 percent on typical medium-rise, 10 to 12 percent on conversion, 15 percent on heritage or unknown-structure work. Sits between hard + soft costs and finance roll-up in the stack.

Bands by scheme risk

  • 5 percent: simple new build on cleared, surveyed greenfield with a tested ground.
  • 7.5 percent: typical medium-rise residential, BCIS general.
  • 10 percent: PDR conversion with prior approval; brownfield with light remediation.
  • 12 percent: Victorian / period conversion in poor condition.
  • 15 percent: heritage or unknown-structure work (barns, churches, mills).

Where contingency sits in the stack

Contingency goes above hard + soft costs (build + fees + s106) and below finance roll-up. It is a cost line, not a deduction from profit; do not double-count by reducing target return for risk and adding contingency.

Lender override

Lender monitoring surveyors typically run their own contingency assumption and may override developer figures. Build to the higher of the two on the appraisal so lender stress-tests do not abort the deal mid-build.

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.