CIL self-build exemption: the forms and the deadlines

The CIL self build exemption is lost on paperwork far more often than on eligibility. The exemption itself is generous: build a house you will live in as your main residence, and the Community Infrastructure Levy on it can fall to nothing. But the Community Infrastructure Levy Regulations 2010 make the relief conditional on a sequence of forms submitted in a fixed order, before specific events, and the collecting authority has limited discretion to forgive a step you skipped.

Get the order right and the exemption is straightforward. Start work before the paperwork is in and you are arguing about a five-figure bill.

Who qualifies

The exemption applies to a whole new dwelling that you are building or commissioning, and that you will occupy as your sole or main residence for three years from completion.

Self-build in this context does not mean you personally lay the bricks. Commissioning a builder, a package supplier or a main contractor is fine. What matters is that the dwelling is yours, that you occupy it, and that you are not building it to sell or to let.

Two related exemptions sit alongside it and use their own forms: a residential annex within the curtilage of your home, and a residential extension. Extensions creating less than 100 m² of new floorspace, with no new dwelling, already fall outside the levy as minor development, so the extension claim form matters mainly for larger additions.

The sequence of forms

This is the part to print out and pin up.

1. Assumption of Liability. Submit this before work starts, in your own name. Somebody must assume liability for the levy even where the expected charge is nil.
2. Self Build Exemption Claim Form Part 1. Submit it after permission is granted and before any work begins. Wait for the authority to grant the exemption in writing.
3. Commencement Notice. Serve it on the collecting authority before the first act of development on site. Keep the acknowledgement.
4. Start on site, after the notice has been served and the exemption granted.
5. Self Build Exemption Claim Form Part 2. Submit it within six months of completion, with the supporting evidence.

Nothing here depends on the planning application itself. The levy process runs in parallel with planning, through the collecting authority's CIL team rather than the case officer, and the two teams often do not talk to each other. Address correspondence to the CIL team by name.

Why the commencement notice is the dangerous step

The first act of development is earlier than most people think. Digging foundations counts. So does demolition where it forms part of the permitted scheme, and so, arguably, does site clearance carried out under a pre-start condition.

Serve the notice before any of that, and keep evidence of service. Email with a read receipt, or post with proof of posting, and file the authority's acknowledgement.

Since the 2019 amendments, failing to serve the notice where an exemption has already been granted is dealt with by a surcharge rather than automatic loss of the whole exemption. That is a meaningful improvement on the previous position, and it is not a reason to relax. Surcharges are real money, authorities apply them, and a disputed commencement date creates exactly the sort of argument a self-builder does not need in month one. Practice varies between collecting authorities, so ask yours in writing how it treats the point.

Evidence for Part 2, within six months

Part 2 is where the exemption is confirmed rather than claimed. The authority expects documentary proof of three things: that the dwelling is complete, that you own it, and that you occupy it as your main residence.

• A building regulations completion certificate, or a new dwelling warranty.
• Title deeds or a Land Registry entry showing your ownership.
• A council tax bill or certificate in your name at that address.
• One further item from the accepted list, typically an approved claim under the VAT refund scheme for self-builders, a specialist self-build warranty, or a self-build mortgage.

Six months from completion sounds generous. It is not, once you allow for a warranty provider taking eight weeks and a council tax account that only opens after occupation. Start assembling the pack while the scaffold is still up.

Miss the deadline and the exemption falls away, and the levy becomes payable in full according to the authority's instalments policy.

The three-year clawback

The exemption is conditional for three years from completion. A disqualifying event in that window makes the levy payable.

The events that bite are selling the property, letting it out, or ceasing to occupy it as your main residence. Converting it to a holiday let counts. Moving out to work abroad and letting the house counts. Death of the claimant, and certain transfers within a family, are treated differently, and the authority should be asked directly rather than assumed.

If a disqualifying event is coming, notify the collecting authority within the period the regulations require. Volunteering it produces a demand for the levy. Concealing it produces a demand for the levy plus a surcharge, and a much less constructive relationship with a council you may need again.

Where exemptions are usually lost

Five patterns account for most failed claims.

Assuming the exemption is automatic because the planning officer mentioned it. It is not, and the planning officer is not the collecting authority.

Starting work while Part 1 is still being determined. The exemption must be granted before any work begins.

Serving the commencement notice late, or not at all, because the groundworker started early.

Missing the six-month Part 2 deadline while chasing a completion certificate.

Selling within three years without telling the authority, then discovering the charge as a local land charge during the buyer's searches.

If you have already missed a step, tell the collecting authority now rather than after the demand notice arrives. Authorities have some discretion over surcharges and instalment arrangements, and they exercise it more readily for people who came forward. Where the charge stands, you can ask for the calculation to be reviewed, and there are formal review and appeal routes with short deadlines of their own.

An illustrative example. A couple building a single house on an infill plot submit the liability form and Part 1 in March, receive the exemption in April, serve the commencement notice on a Friday and start groundworks the following Monday. They complete in the following March and file Part 2 with the warranty and council tax bill in June. That timeline works. The dates here are illustrative.

Wider levy questions, including how the money gets spent locally, are covered in the note on infrastructure funding statements. For the planning documents that sit alongside a self-build application, the full list of report types shows what a single-plot scheme typically needs, and a Planning Statement is usually the first of them.

This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it.

Enter your postcode on PlanScope to see which reports your self-build plot is likely to need.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.