Community Infrastructure Levy in Hillingdon
Residential CIL in Hillingdon is charged per m² of new gross internal area under the council's charging schedule (effective 2014-08-01). Mayoral CIL 2 Band 2 (£72.73/m²) is charged on top by the Greater London Authority. Extensions under 100 m² that create no new dwelling are not liable (reg 42); owner-occupiers can claim the self-build, annex or extension exemption — but only before work starts.
| Zone | Adopted rate | Indexed rate | Applied |
|---|---|---|---|
| Borough-wideResidential Dwelling Houses (C3). Indexed: £95 x 400/237 (Annual CIL Rate Summary 2026).Source: Hillingdon charging schedule · verified 2026-09-18 | £95.00 | £160.43 (2026) | £160.43/m² |
Source: charging schedule · council CIL page · verified 2026-09-18. Single borough-wide residential rate; no residential zones. Schedule adopted 10 July 2014, effective 1 August 2014. Other rates: large format retail A1 >1,000 sqm outside designated centres £215; offices £35; hotels £40; industrial (B8) £5; all other uses £0. Base index 237, 2026 index 400. Instalments policy exists (https://pre.hillingdon.gov.uk/downloads/file/2197/cil-instalments-policy) - not fetched. www.hillingdon.gov.uk CIL path returns 404; live content served on pre.hillingdon.gov.uk.
| Scheme | Liability | Exemption | At stake if filed wrong |
|---|---|---|---|
| Rear extension, 120 m², owner-occupier | £27,979 | Form 9 | £27,979 |
| Garden annex, 60 m², for a relative | £13,990 | Form 8 | £13,990 |
| New self-build house, 180 m² | £41,969 | Form 7 | £41,969 |
| Small developer, 3 flats, 240 m² (no exemption) | £55,958 | none | £55,958 |
Indicative — the council's Liability Notice is definitive. Under 100 m² and no new dwelling is not liable at all (reg 42).
Free liability range and exemption check. The £29 report gives the filing order for Forms 1, 2, 6 and 7/8/9 with dates and the surcharge at each step.
Run the calculator →