Community Infrastructure Levy (CIL) is one of those aspects of the planning process that many self-builders only become aware of when it’s already caused a problem.
In principle, self-build projects are often eligible for a full exemption from CIL. In practice, the exemption only applies if a very specific process is followed, in the correct order. Miss a step, submit something late, or assume it’s automatic — and a significant and unexpected charge can arise.
We’ve had to explain this process to clients many times, so in this article we’ll set out what CIL is, when it applies, and exactly which forms self-builders need to submit to avoid it.
(The form references below are correct at the time of writing, but applicants should always check the latest versions of CIL forms on GOV.UK, as requirements can change.)
What is Community Infrastructure Levy (CIL)?
CIL is a charge that some Local Planning Authorities apply to new development. It’s intended to help fund local infrastructure such as:
- roads and transport
- schools and healthcare
- public spaces and community facilities
Not all councils operate CIL, and rates vary significantly between authorities. Where it does apply, however, the charge can be substantial.
For a new dwelling, CIL is usually calculated based on:
- the net increase in floorspace
- the authority’s published charging schedule
Are self-builders exempt from CIL?
In many cases, yes — but the exemption is not automatic.
Self-build projects may qualify for a self-build exemption, provided that:
- the dwelling is genuinely built or commissioned by an individual for their own occupation, and
- the correct CIL forms are submitted at the correct stages
If the process is not followed precisely, the exemption can be lost even where the project itself would otherwise qualify.
The key point most people miss
The single most important thing to understand is this:
CIL exemption is procedural, not discretionary.
Planning officers cannot apply it retrospectively, and missing deadlines usually cannot be corrected later.
The self-build CIL exemption process (step by step)
While there can be minor local variations, the national CIL process typically follows the sequence below.
1. Before planning permission is granted
Before a planning decision is issued, the following forms must usually be submitted:
- Form 1 – Additional Information
(Provides basic project and floorspace details) - Form 2 – Assumption of Liability
(Confirms who is responsible for any CIL liability) - Form 7 (Part 1) – Self-Build Exemption Claim
(Claims the exemption as a self-builder)
These forms must be received and acknowledged before planning permission is granted.
Submitting them after a decision has been issued is one of the most common — and costly — mistakes.
2. After planning permission is granted
Once permission is issued, the Local Planning Authority should:
- issue a CIL Liability Notice
- confirm whether the self-build exemption has been granted
You should not assume exemption applies unless this is confirmed in writing.
3. Before development starts
Before any material start on site, you must submit:
- Commencement Notice
Starting development without submitting this notice can trigger the full CIL charge, even if exemption was previously approved.
4. After completion of the build
After the dwelling is completed (typically within six months), you must submit:
- Form 7 (Part 2) – Self-Build Exemption Claim (Completion)
This confirms that:
- the dwelling has been completed
- it is occupied as the self-builder’s principal residence
Supporting evidence is usually required.
Common mistakes that lead to unexpected CIL charges
In our experience, problems most often arise where:
- the wrong form is submitted, or forms are submitted late
- commencement begins before notice is given
- responsibility for CIL is assumed to sit with someone else
- a project changes from self-build to development without advice
These are rarely deliberate — they’re usually caused by confusion about the process.
What if circumstances change?
Changes such as:
- selling the plot or completed dwelling
- switching from self-build to development
- delays in occupation
can all affect CIL liability and should be discussed with the authority before action is taken.
Why this matters early in the process
CIL is not the most visible part of a self-build project, but it can have one of the largest financial impacts if mishandled.
Understanding the forms and timing early allows you to:
- budget with confidence
- avoid unnecessary charges
- keep control of your project programme
Final thoughts
Self-build exemption from CIL can represent a significant saving, but it is not automatic and it is not forgiving.
Treat it as a process that needs managing, rather than a formality that will be handled for you, and it becomes far more straightforward.