Garage conversion VAT: what homeowners should check

Most ordinary building work to an existing home is charged at the standard VAT rate, subject to specific HMRC exceptions. A garage conversion does not automatically qualify for reduced VAT simply because it creates a habitable room. The contractor should show the VAT treatment clearly and apply current HMRC rules to the actual building, use and scope.

Why the usual assumption is risky

HMRC treats different types of construction, conversion, renovation and adaptation differently. Converting part of an existing single dwelling into another room is not automatically the same as converting a non-residential building into a qualifying dwelling. The words “garage conversion” do not decide the VAT liability.

Some work for disabled people in their private residence may qualify for a separate relief, and some qualifying conversions can be reduced-rated. Those rules have detailed conditions. They should not be inferred from a room name, a builder's marketing description or an estimate found online.

What the quotation should show

• Whether the prices are inclusive or exclusive of VAT.
• The contractor's VAT registration details where relevant.
• Which parts of the work and materials have each VAT treatment.
• Whether professional fees, skips, hire, carpets, fitted furniture or other items are treated differently.
• What evidence or certificate the contractor needs before applying a relief.

Ask for the VAT position before comparing totals. A quote that hides VAT can look cheaper without being cheaper. If a project has an unusual use, changes the number of dwellings or is being adapted specifically for a disabled person, read the relevant HMRC notice or obtain professional tax advice.

Keep the claim narrow

This page is general information, not a tax calculation or advice about your personal circumstances. HMRC's VAT Notice 708 explains the conditions. Ask the contractor to explain their treatment and check the current HMRC guidance if the facts are not straightforward.

Separate construction from professional services

HMRC's treatment can differ between qualifying building work, supplied materials, professional fees, hire, waste, carpets and fitted furniture. Ask the contractor whether the quote is a single supply or several supplies and whether an eligibility certificate is required. Keep the written explanation with the invoice rather than relying on a verbal promise.