Last updated: 14 October 2026
Can you claim the cost of demolishing an outbuilding on a buy-to-let?
Usually not against rental income. Demolishing an outbuilding is generally a capital cost, as it changes the property rather than repairing it. You can’t deduct it from rent, but you can usually add it to the property’s base cost for capital gains tax, which reduces your gain when you sell. The exception is if the demolition is part of a genuine repair, such as removing a dangerous structure and restoring the garden to its previous state.
Revenue or capital?
| Work | Treatment | Why |
| Repairing a shed roof | Revenue, deductible | Restores the asset |
| Demolishing an outbuilding to clear space | Capital | Changes the property |
| Demolishing to build an extension | Capital, part of the building cost | Improvement |
| Removing a dangerous structure after storm damage | May be revenue | Making good damage |
| Replacing a garage with a like-for-like garage | Usually revenue | Repair of the whole |
Capital gains tax
Capital costs that are “reflected in the state or nature” of the property when you sell can be added to its base cost. If the demolition makes the property more valuable or usable, for example by creating parking or garden space, the cost should count. Keep the invoices.
Example
Neil owns a buy-to-let house with a derelict brick outhouse. In 2026 he pays £4,500 to demolish it and landscape the area. HMRC would treat this as capital. He can’t deduct it from his 2026/27 rental income. When he sells the house, the £4,500 is added to his base cost. At 24% CGT, that saves £1,080.
Replacing domestic items relief
If you replace furniture, white goods or carpets in a let residential property, you can claim the cost of the replacement, but not the first purchase. This doesn’t apply to buildings or outbuildings.
Capital allowances
Residential landlords can’t claim capital allowances on the property, except for assets in common parts of blocks. Commercial landlords may claim allowances on plant, and structures and buildings allowance at 3% a year on new buildings.
Planning and other costs
- Demolition may need planning permission or building control approval
- Legal and survey costs relating to the demolition are also capital
- If you’re VAT registered for a commercial let, VAT may be reclaimable
Common mistakes
- Deducting demolition and clearance costs from rental income in the year paid
- Losing invoices, so the cost cannot be added to the base cost years later
- Treating the cost of a new garden room as a repair because it replaced an old shed
Keeping records
Keep invoices, photos before and after, and any planning or building control documents. You may not sell the property for many years, so store them safely with the purchase records.
Frequently asked questions
Can I spread the cost over several years?
No, there’s no annual allowance for capital costs on residential lets.
What if the outbuilding was already falling down?
It may be a repair if you restore it, but demolition is capital.
Does it matter if I’m a company landlord?
Companies also add capital costs to the base cost.
Are skip hire costs deductible?
They follow the same treatment as the work.
Related: reporting service charges, jointly owned rental income and former rental property relief.
Talk to Accotax
Want this handled for you? Our team at Accotax can help with landlord tax and expenses. See our landlord accountants service, or contact us for a free, no-obligation quote.
This page is general guidance based on HMRC rules for the 2026/27 tax year, checked against gov.uk on 14 October 2026. It is not personal advice, so speak to an accountant about your own situation.
