Section 106 calculator: 6-head contribution estimator across 10 LPAs.
Built for the development manager sizing a scheme pre-application. Inputs the LPA, unit count and GIA. Returns the deterministic £/dwelling, the 6-head breakdown (affordable housing, education, open space, healthcare, transport, monitoring fee) and an optional combined load with CIL and BNG. Every rate is BCIS-rebased to 2026 Q2 and tied to the adopted SPD.
S106 §1:200BCIS rebase 2026 Q2 · SPDs hand-verified
Headline £/dwelling
£15,370
above median £14,500/dwelling
S106 sub-total
£768,500
Combined total
£768,500
Birmingham City Council · SPD: 2021
Affordable housing commuted sum
15% shortfall x 8 dwellings @ £38,000/dwelling
£304,000
Education
50 dwellings @ £5,400/dwelling
£270,000
Open space + play
50 dwellings @ £1,900/dwelling
£95,000
Healthcare (primary care)
50 dwellings @ £700/dwelling
£35,000
Transport (urban-brownfield x1)
50 dwellings @ £1,200/dwelling
£60,000
Monitoring fee
6 obligations @ £750/obligation
£4,500
Direct answer · 47 words
A section 106 calculator estimates the planning-obligation £ payable under s.106 of the Town and Country Planning Act 1990. For a typical 50-unit urban-brownfield scheme in a non-London LPA, expect £12,000 to £18,000 per dwelling across the six standard heads of contribution, before any CIL or BNG layering.
S106 §1:100 · methodology
How the estimate is built
The 10 supported LPAs (Birmingham, Manchester, Leeds, Bristol, Cornwall, RBKC, Camden, Cambridge, Milton Keynes, plus the regional fallback) carry rates hand-extracted from each council's adopted SPD and rebased to BCIS All-in TPI 2026 Q2 [BCIS All-in TPI]. The 6 heads of contribution follow the structure of CIL Regs 2010 reg 122[CIL Regs 2010 reg 122] and the PPG Planning Obligations guidance [PPG Planning Obligations]. The monitoring fee is constrained by the CIL (Amendment) Regs 2019 reg 4[CIL (Amendment) Regs 2019], which formalised the £500 to £1,200 per-obligation range. The viability red/amber/green chip uses the £14,500/dwelling median across the 10 supported LPAs (urban-brownfield, 20% AH delivered, no CIL or BNG).
S106 §1:50 · recent changes
What changed in 2026
29 Apr 2026
English Devolution and Community Empowerment Act amendments to s.106 received Royal Assent [legislation.gov.uk]. New strategic-authority tier interacts with LPA negotiation; transitional treatment of in-flight obligations is set out in /regulation/devolution-act-2026.
Dec 2025
BNG reform package consultation closed; statutory-credit re-price trajectory carried into the Jul 2026 review window. See /bng/exemptions-2026.