Is a new commercial roof tax deductible?
Updated 23 October 2026 · SEO Dons Editorial
Is re-covering a flat roof a repair or capital expenditure?
HMRC's Business Income Manual sets four basic positions: repairing an asset is normally allowable revenue expenditure, while replacing, altering or improving it is normally capital and not allowable as a deduction. The result "will often be a question of fact and degree", so the test is what was actually done, "not what might have been done" (BIM35430).
The first step is to identify the asset. Replacing part of an asset is a repair to it; replacing the whole is not (BIM46901). The manual says resurfacing a road "is no more a replacement of the road than a new roof replaces a building" (BIM35440), and its worked example has a company completely renewing the roof of its showroom-and-warehouse premises: "The new roof simply returns the roof to original condition. It is neither an alteration nor improvement; it is simply a repair of the building" (BIM46915). The guidance applies "equally to property businesses" as well as trades (BIM46900).
New materials do not change that on their own. The manual says the use of new materials "does not mean that the repair is not allowable" (BIM46901), and that material that is "simply what would normally have been used for that type of job at the time the work was done" is likely to be seen as a repair (BIM35455). Once double glazing became the norm, replacing single glazing was "simply replacing like with currently available like" (BIM46925). A current-specification membrane replacing a worn-out covering is the roofing parallel. Insulation raises a separate question, covered below.
What turns a roof job into capital expenditure?
Work that changes what the building can do, work that is really part of buying it, and a lease promise to put the premises right all point towards capital. These hypothetical scenarios are not advice.
| Illustrative scenario | Starting point in HMRC's manuals | What may follow |
|---|---|---|
| A 2,000 square metre warehouse roof is stripped and re-covered with a current system doing the same job | A repair of the building (BIM46915, BIM35455) | Deducted when the cost goes through the accounts (BIM46901) |
| The same re-roof also enlarges the building | Alteration and improvement, so capital (BIM46915); a court HMRC cites refused to treat part of such a roof as a notional repair (BIM35465) | Allowances on the capital cost, if any apply |
| An uninsulated roof is re-covered and insulation is added for the first time | Added insulation is plant and machinery expenditure where no other relief is available (CA22220); the covering is a separate question | Special rate pool for the insulation; the split depends on the facts |
| A building is bought with a failed roof and a price that reflects it | May be part of the cost of acquiring the building (BIM46935) | Capital; routine maintenance after purchase can still be a repair |
| A tenant agrees, as part of the lease, to restore the premises to a good state of repair | Capital (BIM46940) | Possible premium-legislation relief; see flat roof dilapidations |
Where a programme mixes work, "some works may simply be repairs, while others are alterations or improvements" (BIM46915), so an itemised scope matters. But an improvement attracts "no revenue deduction for any part of the expenditure", and a taxpayer who chooses to improve "cannot claim relief for notional repairs" (BIM35465).
What relief applies to the capital part?
Capital spending is not deducted as a repair, but allowances may apply to parts of it. None is automatic.
- The roof covering is not plant and machinery. gov.uk says plant and machinery allowances cannot be claimed on "buildings, including doors, gates, shutters, mains water and gas systems", and its list of integral features (lifts, heating, air-conditioning, water, electrical and lighting systems, external solar shading) includes neither roofs nor insulation. If spending on an integral feature exceeds 50% of its replacement cost, HMRC treats the whole as capital (BIM46945), which matters for rooftop services replaced with a re-roof.
- Insulation added to an existing building. Section 28 of the Capital Allowances Act 2001 covers expenditure "adding insulation against loss of heat". HMRC's manual treats it as capital expenditure on plant or machinery, counts "roof lining" as insulation, and says relief is "only available" for insulation added to an existing building. gov.uk puts "thermal insulation you've added to a building" in the special rate pool, at 6%. For a company, half of special rate spending can be deducted under the 50% first-year allowance, and it "may qualify" for the annual investment allowance. The manual applies the allowance "if no relief (either an allowance or deduction) is otherwise available", so a deductible repair comes first.
- Structures and buildings allowance (SBA). gov.uk gives 3% a year over 33 and one third years on construction costs, including "renovation, repair and conversion costs", where all construction contracts were signed on or after 29 October 2018. HMRC treats renovation, conversion and incidental repairs as construction "for the first time", and only repairs "not allowable as a deduction" count. Costs that also qualify for plant and machinery allowances are excluded, as are land, planning permission, financing and legal costs. An allowance statement is needed, and claims stop on sale.
Whether a given roof project is "renovation" for SBA is for the accountant. The grants and funding guide sets these tax points beside the other routes that touch a roof budget.
How does VAT apply to a new commercial roof?
HMRC's Notice 708 says "the construction of a new building and work to an existing building is normally standard-rated", with exceptions listed in the notice; gov.uk gives the standard rate as 20%. A VAT-registered business making taxable supplies normally treats the VAT as input tax. But "in principle" VAT relating to non-business activity or exempt supplies cannot be reclaimed, and a partly exempt business "probably will not be able to claim all your input tax", so a landlord with exempt lettings, or an organisation with non-business use, should check recovery before budgeting. For allowance pools, gov.uk says to include VAT in the value only if you are not VAT registered.
The domestic reverse charge can change who accounts for the VAT. gov.uk says a VAT-registered buyer of building and construction services must use it where payment is reported within the Construction Industry Scheme, among other conditions, unless an end user or intermediary supplier notifies the supplier in writing. The buyer then records it on its own VAT return, so the invoice is worth checking with the accountant.
What should be on file for the accountant?
HMRC says evidence of the work done may include "the estimate from the contractor and any written instructions from the taxpayer setting out what work was to be done" (BIM46911). A file that answers each test helps:
- A survey or photographs of the roof's condition and build-up before work; see survey types and scope.
- The specification, stating whether the aim was to restore the roof or change what the building can do.
- An itemised contract sum separating the covering, any added insulation, any extension and rooftop plant.
- For a purchase, the sale papers showing whether the price reflected the roof's condition.
- The earliest construction contract (gov.uk says to keep it for SBA) and the lease position; see who pays for a commercial roof.
None of this is tax advice for a particular case. The answer depends on the facts, and an accountant should confirm it. The repair or replace guide covers the technical decision and the cost guide what drives the price.
Sources
- Business Income Manual, HMRC, updated 4 August 2026, checked 22 October 2026: BIM35430, BIM35435, BIM35440, BIM35455, BIM35465, BIM46900, BIM46901, BIM46911, BIM46915, BIM46920, BIM46925, BIM46935, BIM46940, BIM46945.
- Capital Allowances Manual, HMRC, checked 22 October 2026: CA22220 and CA93200.
- Capital Allowances Act 2001, section 28, section 270AA and section 270BJ, legislation.gov.uk, checked 22 October 2026.
- HMRC on gov.uk, checked 22 October 2026: what you can claim on, rates and pools, work out what you can claim, structures and buildings, full expensing and 50% first-year allowance, VAT Notice 708, charging VAT, VAT Notice 700 and the domestic reverse charge.
Common questions
Is routine roof maintenance treated differently?
HMRC's manual says the cost of routine repairs and maintenance remains allowable expenditure even after a change of ownership. A planned maintenance programme is a different question from a renewal, but each invoice should still reflect what was actually done.
Does the same approach apply to a landlord?
HMRC says its repairs guidance applies equally to property businesses. The insulation rule also covers a landlord adding insulation to a let building, other than a dwelling-house.
Does a more durable material make the work an improvement?
Not by itself. HMRC warns that modern materials may give an apparent element of improvement, but the work is a repair if the asset can just do the same job as before.
Does it matter that replacement was cheaper than repair?
HMRC says the fact that replacing the whole asset is cheaper than repairing it is not relevant, and that being the cheapest option does not make replacement allowable. On the manual's wording, a new roof does not replace a building.