What does a Heritage Impact Assessment cost in 2026?
A one-page Heritage Statement runs £150 to £400. A proportionate Grade II HIA runs £800 to £3,500. A Grade I or strategic case with Archaeology Desk-Based Assessment runs £1,500 to £5,000 and above. Regional rate multipliers add or subtract roughly ±18% versus the South-West baseline.
How the estimator works
The estimator multiplies a consultant day rate by an estimated number of days for the scope of works, applies a regional multiplier, then adds itemised extras (site visit, archaeology DBA, conservation-accreditation uplift). Day rates are calibrated to RIBA Fee Calculator and theCIfA Salary minima for principal-grade practitioners.
A consultant day rate of £760 (mid) for Grade II work assumes a chartered or IHBC-accredited author working at the median of the Royal Institute of British Architects benchmark range for conservation services. Day rates climb for higher-grade designations because Grade I work attracts senior partners.
When the calculator flags a warning
Selecting Grade I with major works and no site visit will trigger a scope-warning chip. Most LPAs treat a site visit as compulsory for Grade I cases; submitting an HIA without one is a common reason for unvalidation.
Regional rate multipliers
- London 1.18 , partner-grade rates at top of the RIBA range
- South-East 1.08
- South-West / baseline 1.00
- Midlands and North 0.96
- Wales 0.96
- Scotland 1.00 , HES guidance, narrower consultancy market
What the estimator does not include
- Planning application fees (paid to the LPA, not the consultant)
- Drawings, photographic survey or measured survey work
- Specialist reports (BS 7913, BS 8210, Townscape and Visual Impact, ecological)
- Appeal or inquiry work (paid hourly, separately)
- VAT (figures above are ex-VAT)