Property Development Calculator: Scheme Presets

Nine scheme-type presets. Each preset loads the workbench with default unit count, GIA, BCIS build cost, professional fees, contingency, finance and target profit-on-cost. Adjust from there.

New build residential, 6 to 15 units9 units · 20% PoC

Medium-rise blocks or terraces. BCIS general new-build rate; CIL and BNG itemised per unit.

Build 2,400 £/sqmFees 12%Contingency 7.5%Finance 9.5%
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Small sites, 1 to 9 units (NPPF preset)4 units · 20% PoC

NPPF Dec-2025 small-sites threshold. BNG exemption to 1 sept 2026 transition; CIL minor-development relief.

Build 2,300 £/sqmFees 11%Contingency 7.5%Finance 9.75%
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Permitted development to C3 (PDR)6 units · 20% PoC

Class O, MA or G prior-approval conversion. NDSS now applies; daylight or BRE often kills schemes pre-residual.

Build 1,850 £/sqmFees 10%Contingency 10%Finance 10%
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Office-to-residential conversion12 units · 22% PoC

Class O PDR or full planning conversion. BCIS conversion rate is roughly 70 to 80 percent of new build.

Build 1,750 £/sqmFees 11%Contingency 12.5%Finance 10.5%
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Barn conversion (Class Q)2 units · 25% PoC

Class Q PDR up to 10 dwellings, 150sqm cap. Unknown-structure conversions justify 15 percent contingency.

Build 1,950 £/sqmFees 9%Contingency 15%Finance 10.5%
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Self-build, single dwelling1 units · 15% PoC

Single dwelling self-build with HMRC VAT reclaim on materials. Target return lower than commercial development.

Build 2,200 £/sqmFees 8%Contingency 10%Finance 9.75%
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Mixed-use (commercial yield + residential)4 units · 22% PoC

Ground-floor retail or office capitalised on NOI/yield, residential units priced on £/sqft.

Build 2,550 £/sqmFees 12%Contingency 10%Finance 10%
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HMO (yield-based)1 units · 22% PoC

HMO converts a single C3 dwelling to sui generis or C4. GDV sized as NOI capitalised at 7 to 9 percent yield.

Build 1,750 £/sqmFees 9%Contingency 10%Finance 10.25%
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Build-to-rent (BTR)60 units · 18% PoC

BTR GDV is NOI / net initial yield. Op-cost ratio 25 to 30 percent of gross rent; yield 4.25 to 5.5 percent.

Build 2,650 £/sqmFees 12%Contingency 7.5%Finance 9%
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National Planning Policy Framework, Dec 2025 revision· Dec 2025Appraisal model reviewed by Oliver Wakefield-Smith (data integrity) with chartered-surveyor (MRICS) and CTA tax review. No affiliate links.