When CIL applies vs Section 106
- CIL is a tariff-style charge calculated as £/sqm of net additional floorspace.
- Section 106 covers site-specific obligations (affordable housing, infrastructure, contributions).
- Both can apply on the same scheme but a CIL R123 list (now historical) used to bar double-charging for the same item.
BNG 10 percent requirement
- Statutory BNG in force from 12 Feb 2024 (major sites) and 2 Apr 2024 (small sites).
- From 6 Aug 2026 a new exemption covers sites up to 0.2ha with no on-site priority habitat; the self-build and custom-build exemption is removed (retained only for applications submitted before 6 Aug 2026).
- Schemes must deliver 10 percent net gain in biodiversity units against a baseline.
- Off-site units price varies; Natural England's statutory biodiversity credits run from £42,000 per credit (tier A1, the cheapest) to £650,000 (tier A5), and a spatial risk multiplier means you must buy two statutory credits per biodiversity unit, so they are priced as a deliberate last resort.
How CIL is calculated
CIL liability = (chargeable area in sqm) x (council CIL rate £/sqm) x (RICS CIL Index ratio Ip/Ic: the index for the year planning permission is granted, divided by the index for the year the charging schedule took effect). BCIS calculates the RICS CIL Index from its All-in Tender Price Index; it replaced the standalone All-in Tender Price Index for permissions granted on or after 1 January 2020.
Small-sites CIL relief
Schemes that fall below CIL minimums (100 sqm net additional floorspace, 1 dwelling) qualify for self-build relief or minor-development relief. Always check the council's adopted CIL charging schedule.