Self-build levy exemption or the annexe exemption
Two Community Infrastructure Levy exemptions, two sets of conditions, and one shared trap. Here is how the self-build and residential annexe exemptions differ and where each one is lost.
If you are building a house to live in, you want the self-build exemption. If you are adding a granny annexe inside the curtilage of the house you already live in, you want the residential annexe exemption. Both remove the Community Infrastructure Levy charge, both are set out in the Community Infrastructure Levy Regulations 2010, and both are lost permanently if you start work before the paperwork is granted. That last sentence is the one worth reading twice.
What each exemption covers
The self-build exemption applies to a whole new dwelling built by, or on behalf of, an individual who will occupy it as their sole or main residence. It does not matter whether you laid the bricks yourself. Commissioning a builder to construct a house you will live in still counts.
The annexe exemption applies to a new dwelling built within the curtilage of an existing main dwelling, where you own an interest in that main dwelling and live in it. A separate provision covers residential extensions, and most extensions under 100 square metres of gross internal area already fall outside the levy as minor development.
Neither exemption touches anything other than the levy. Your planning fee is still payable. Any section 106 obligation still applies. The exemption is a levy relief, nothing wider.
Eligibility conditions side by side
| Self-build dwelling | Residential annexe | |
|---|---|---|
| What is built | A new dwelling on its own plot | A new dwelling inside the curtilage of the main house |
| Who claims | The individual who will live in it | The owner and occupier of the main dwelling |
| Occupation test | Sole or main residence of the claimant | Main dwelling is the claimant's sole or main residence |
| Clawback period | Three years from completion | Three years from completion |
| Claim form | Self build exemption claim, submitted in two parts | Self build annexe claim, one part |
The annexe route carries an extra structural condition that catches people out. The annexe has to sit wholly within the curtilage of the main dwelling, and it has to remain ancillary in ownership terms. Draw a plot boundary around it for a future sale and you have created the disqualifying event before you have finished.
The forms and the order they go in
Order matters more than content here, and the order is not intuitive.
- Assume liability for the levy using the assumption of liability form, even though you intend to claim an exemption.
- Submit the exemption claim and wait for the authority to grant it in writing.
- Serve the commencement notice, giving the date you intend to start.
- Start work, and not before step three.
- For a self-build dwelling, submit the second part of the claim within six months of completion with the supporting evidence.
Step two is where the regime is unforgiving. The exemption has no effect if development starts before the collecting authority has notified you of its decision on the claim. There is no discretion to reinstate it afterwards. A digger on site the week before the decision letter arrives costs the full charge.
For the mechanics of the notice itself, the sequence is set out in our guide to liability notices, commencement notices and surcharges.
Why the start notice still matters
Serving a commencement notice late used to remove the exemption outright. The 2019 amendments softened that, so an authority now generally imposes a surcharge rather than withdrawing relief where the notice was missed but the claim itself was properly granted first. The surcharge is capped, and it is still money you did not need to spend.
Treat the notice as non-negotiable anyway. Authorities differ in how they handle a late one, the rules have been amended more than once, and the consequences of getting it wrong sit entirely with you. Our note on what happens if you miss the commencement notice goes through the practical recovery options.
Check the current consolidated regulations on legislation.gov.uk before relying on any summary of the surcharge position, including this one.
Clawback and the events that trigger it
Both exemptions run a three year clawback period from the date the building is finished. During that window, certain events cause the levy to become payable in full.
For a self-build dwelling, the disqualifying events are the dwelling ceasing to be your sole or main residence, letting it out, or selling it. For an annexe, the events are letting the annexe separately, or selling either the annexe or the main dwelling separately from the other.
A few practical consequences follow. Renting the annexe to a lodger on a tenancy is a disqualifying event. Selling the main house with the annexe attached, as one title, is not. Moving into a self-build and then taking a two year job abroad while keeping the house empty is a question about sole or main residence, and it is worth taking advice before assuming it is safe.
You are required to tell the collecting authority within 14 days if a disqualifying event happens. Not doing so attracts a surcharge on top of the charge.
The clawback period runs from completion rather than from the decision, so a scheme that takes two years to build carries the restriction for five years in total. Plan around that if a sale or a move is likely, and keep the completion certificate safe, because it fixes the date the clock started.
Evidence after completion
The annexe claim has no second stage. The self-build claim does, and it is the part people forget because it falls due six months after the excitement of moving in.
Within six months of completion you submit the second part of the claim with three kinds of evidence: proof that the building is finished, proof of your title to the dwelling, and proof that the project is a self-build in substance. That last one is usually satisfied by an approved claim under the VAT refund scheme for DIY housebuilders, a self-build warranty, or a self-build mortgage. Keep whichever one you are relying on from the start rather than assembling it in a panic.
Miss the six month window and the exemption falls away. This is a hard deadline in the regulations, not an administrative preference.
Recovering from a mistake
Be honest about what can and cannot be fixed.
A missed commencement notice is usually survivable, at the cost of a surcharge. A missed six month evidence deadline is not. Starting work before the claim was granted is not. In those cases the conversation with the authority is about the payment schedule and any instalment policy, rather than about the exemption.
If you are at the stage of choosing between a full application for a separate dwelling and a householder application for an annexe, the levy consequences should be part of that decision rather than an afterthought, and the differences are set out in our comparison of the householder and full application routes.
This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it.
See PlanScope pricing if you want a draft Planning Statement to go with the application that starts this process.
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Frequently asked questions
Can I claim the self-build exemption if a builder constructs the house?
Yes. The regulations refer to a dwelling built by or on behalf of an individual who will occupy it as their sole or main residence, so employing a main contractor does not disqualify you. What matters is who commissions the work and who lives there afterwards. You still need the supporting evidence at the second stage, such as an approved VAT refund claim, a warranty or a self-build mortgage.
What happens if I start building before the exemption is granted?
The exemption has no effect and the full levy becomes payable. This is the one failure that cannot be undone, because the regulations require the collecting authority to have notified its decision before development starts. There is no appeal against the outcome and no discretion to reinstate the relief, so wait for the decision letter before any work begins on site.
Does letting a room in my annexe cancel the exemption?
Letting the annexe as a separate dwelling within the three year clawback period is a disqualifying event and makes the levy payable in full. A family member living there without a tenancy is a different matter. The distinction turns on whether the annexe is let separately, so take advice before granting any form of tenancy during the clawback period.
Do I need to assume liability if I am claiming an exemption?
Yes. Submit the assumption of liability form first, then the exemption claim. Authorities frequently reject or delay claims where liability has not been assumed, because the exemption operates by removing a charge from a liable party. Doing both at the same time, well before you expect to start, avoids a sequencing problem that is otherwise easy to create.
Is the residential extension exemption the same thing?
No. It is a separate relief for extensions to an existing dwelling, and most extensions below 100 square metres of gross internal area already fall outside the levy as minor development. The annexe exemption applies where the work creates a new dwelling within the curtilage. Check which of the three your project actually is before choosing a form.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.