S106 §1:100 · combined load
Combined CIL + S106 + BNG cost calculator
Direct answer · 47 words
Combined load is the sum of CIL (per sqm GIA by charging schedule), the S106 6-head contribution, and BNG (units multiplied by unit cost at the chosen delivery route). The estimator below layers all three on the same scheme input and surfaces the per-dwelling combined total against the viability median.
S106 §1:100 · CIL + S106 + BNGBCIS 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
S106 §1:50 · what to watch
Anti-double-counting rule
Infrastructure funded via CIL cannot also be sought via S106. The reg 122 necessity test applies to every S106 head; transport and education heads are the most commonly contested when CIL is in force in the LPA. Where the LPA has not adopted CIL, S106 absorbs the entire infrastructure load (Manchester, Birmingham and Milton Keynes are the headline examples among the supported LPAs).
S106 §1:50 · go deeper