S106 §1:100 · vendor

Dixon Searle Partnership (DSP)

Reviewed by Chartered Planner (MRTPI) and Chartered Surveyor (MRICS) · 2026-06-21
Direct answer · 52 words
Dixon Searle Partnership (DSP) is a UK viability consultancy retained predominantly LPA-side. With Three Dragons it co-authored the GLA Affordable Housing & Viability toolkit underpinning the GLA Excel calculator. DSP is widely engaged by Cornwall, Cambridge and district councils to set CIL/S106 viability evidence and review developer FVAs.

Pricing position

Quote only; LPA-side viability and toolkit-authoring engagements. Source: dixonsearle.co.uk (verified 2026-06-21).

Co-author with Three Dragons of the GLA Affordable Housing & Viability toolkit; widely retained by LPAs (Cornwall, Cambridge, district councils) to set CIL/S106 viability evidence and review developer FVAs.

DSP publishes no list price. Engagement is by fixed-fee study brief agreed with the commissioning LPA or applicant.

GLA toolkit lineage

The GLA Affordable Housing & Viability toolkit (Three Dragons-maintained, DSP co-authored) is the reference Excel model for commuted-sum calculation across London boroughs. See the S106 AH Calculator vendor entry for the published GLA download.

LPA-side review of developer FVAs

Where an applicant submits an FVA arguing a viability shortfall, DSP is one of a small group of consultancies routinely instructed by the LPA to review the assumptions, contest the BLV and the threshold-test profit, and recommend an open-book review mechanism if the contribution is reduced at consent.

Three Dragons partnership

Three Dragons and DSP have co-authored toolkits and area-wide viability studies for over a decade. The combination is the de-facto LPA-side benchmark in the south of England and London; Lichfields more commonly sits on the applicant side.

S106 §1:50 · related

Related

LichfieldsS106 AH CalculatorApraoViabilityMethodologyCalculator