CIL forms cost from £49 at Fixed Fee Plans on their own, and they are included free with every planning service we sell. We complete the Community Infrastructure Levy forms your application and your start on site need, and we tell you first if you owe nothing and need only one.
CIL is the levy a council charges on new floor space to pay for local infrastructure. For most householder extensions it is nil. The forms are still worth getting right, because the penalties are for paperwork, not for building, and they fall on owners who did not know a form existed.
Do I have to pay the levy on my extension?
Often not. Regulation 42 of the Community Infrastructure Levy Regulations 2010 says liability does not arise on development where the gross internal area of new build will be less than 100 square metres, unless the development comprises one or more dwellings. The practice guidance says most new development creating net additional floor space of 100 square metres or more, or a new dwelling, is potentially liable, and that some residential annexes and extensions, and self-build homes, can be exempt.
That means an ordinary rear extension of 25m² owes nothing. A conversion of a house into flats creates dwellings and is a different case, and a larger extension may cross 100m². Each council that charges publishes a schedule of rates on its website, and London also has a Mayoral levy that boroughs collect. We read your scheme against both before saying whether anything is due, so you know the figure, which can be nil, before the application goes in.
What forms are there, and when are they due?
Four, and the timing matters more than the content. The CIL information your council asks for goes in with the planning application. If your extension or annexe qualifies for the exemption, the claim must be received by the council before work starts, under regulation 42B, and it lapses if work starts before the council has decided. Where levy is due, someone must submit an assumption of liability notice under regulation 31 to name the person who will pay.
The last is the commencement notice, which regulation 67 says must be submitted no later than the day before work starts. It does not apply where the development is below the 100m² exemption, where an exemption for residential extensions was granted, or where the chargeable amount is zero. A notice sent on the morning work starts is already late, and the penalties apply from the day the work begins.
What are the penalties for a missed form?
Modest on paper, harsh in practice. A council may impose a £50 surcharge on each person liable if nobody assumed liability and the development has begun, under regulation 80. If work starts before a valid commencement notice is received, regulation 83 allows a surcharge of 20% of the levy or £2,500, whichever is lower.
The larger cost is losing an exemption. A claim for the residential extension exemption that is not in before work starts lapses, so an owner who should have paid nothing owes the full levy. We put the deadline in writing in your pack, with the day by which the form must arrive, not the day it was posted, and tell your builder.
What does it cost?
Our fee is from £49 for the forms on their own, and it is a floor: a scheme with several dwellings or a complicated exemption claim is quoted in writing. They are included free with every planning service, such as our complete planning drawing service at £645 drawings + £150 survey (£795 total) and the application pack. The levy itself, where there is one, is paid to your council and never added to our fee. If you only need to know whether your project needs an application at all, the permitted development checker is free, and our two-flat conversion drawings cover the case where dwellings are created.
Frequently asked questions
Do I pay CIL on a house extension?
Usually not. Liability does not arise on development with less than 100 square metres of new build, unless it creates a dwelling, and extensions that qualify for the residential extension exemption pay nothing if the claim is made before work starts.
Do I need a commencement notice if I owe nothing?
Regulation 67 does not apply where regulation 42 applies, where an exemption for residential extensions was granted, or where the chargeable amount is zero. We tell you which case yours is.
What happens if I build before sending the form?
The council may impose surcharges: £50 where nobody assumed liability, or 20% of the levy or £2,500 for a missed commencement notice, and a lapsed exemption claim means the levy is due in full.
Is this included with your planning service?
Yes. The CIL forms are included free with every planning service we sell, and sold on their own from £49.