Structures and Buildings Allowance (SBA): The Trade Business Guide (UK)

What Is the Structures and Buildings Allowance?

SBA is a capital allowance that lets you write off the cost of constructing or acquiring a non-residential structure or building against your taxable profits. It was introduced for contracts entered into on or after 29 October 2018 — so any qualifying spend tied to a contract before that date doesn't qualify.

The point of SBA is to fill a gap. For decades, the actual fabric of a commercial building — the walls, floors, roof and structural elements — attracted no tax relief whatsoever, even though plant and machinery inside it did. SBA changed that. If you spend money building or buying a qualifying commercial structure, you can now claim relief on that expenditure, slowly, year after year.

The Rate: A Flat 3% Per Year

SBA is given at a flat rate of 3% per year on a straight-line basis. That means you claim the same fixed amount every year — 3% of the qualifying cost — until the whole amount is written off. At 3% a year, the relief runs over 33⅓ years.

Straight-line is different from the reducing-balance method used for some other allowances. You don't claim a percentage of the dwindling remaining balance — you claim a flat 3% of the original qualifying cost each year, every year, until it's gone. It's slow relief, but it's relief that didn't exist before, and over the life of a building it adds up to the full cost of the structure.

The allowance starts from the later of the date the qualifying expenditure is incurred and the date the building is first brought into qualifying use. If the building sits empty before you start using it for the trade, the clock doesn't run during that period.

What Qualifies for SBA

SBA covers the cost of physically creating or improving a non-residential structure. For a trade business, the qualifying spend typically includes:

• Construction costs of a new commercial building — building a workshop, unit, yard building or office from scratch.
• Renovation and improvement of an existing qualifying structure — work that goes beyond a repair and creates new structure.
• Conversion costs — converting a structure to bring it into qualifying commercial use.
• Fit-out of the structure itself — the structural elements of a fit-out (walls, floors, ceilings forming part of the building) rather than loose plant.
• The cost of an unused building bought from a developer, where the price reflects construction cost rather than land.

The common thread is that you're paying for structure — the physical building — and that it's used for a qualifying activity such as a trade. A workshop you build to run your business from is the textbook case.

What Does Not Qualify

Plenty of costs that feel like they should be part of the building don't qualify for SBA. The main exclusions are:

• Land. The cost of the land itself, and costs of altering land, are excluded. SBA is for structures, not the ground they stand on. When you buy a building, you have to strip out the land element of the price.
• Residential property and dwellings. SBA is for non-residential use only. A flat above the workshop, or any part used as a dwelling, doesn't qualify.
• Costs that get plant and machinery allowances or the Annual Investment Allowance instead. Integral features and qualifying plant go down the AIA route — you can't double up (more on this below).
• Planning, legal and financing costs. Professional fees for planning permission, legal costs of acquiring the property and the costs of arranging finance are not qualifying SBA expenditure.
• Stamp duty land tax and similar acquisition taxes on the land element.

The Allowance Statement — You Need One to Claim

This is the part that trips people up. To claim SBA you must hold a written allowance statement. Without it, you can't claim — and you can't claim for any period before you have one.

The allowance statement must record key information including the date of the earliest written contract for construction, the total qualifying costs, and the date the building was first brought into non-residential use. The person who first incurred the qualifying expenditure creates the statement.

The allowance statement matters most when you buy a building rather than build it. If you purchase a qualifying structure from a previous owner, you need to obtain the allowance statement from them to continue claiming. No allowance statement passed across at sale means the buyer cannot claim SBA on that building — so if you're buying commercial premises, ask for it as part of the deal.

How SBA Interacts With Capital Allowances and AIA

You cannot claim SBA and plant and machinery allowances on the same pound of expenditure. Each item of spend goes down one route or the other, not both.

In practice, when you build or fit out commercial premises, the cost gets split:

• Integral features and plant and machinery — things like electrical systems, heating and air conditioning, lifts, and loose equipment — go to capital allowances, where the Annual Investment Allowance (AIA) can give 100% relief in the year of spend (up to the AIA limit). This is far faster relief than 3% a year.
• The structure itself — the walls, floors, roof and structural fabric — goes to SBA at 3% a year.

Because AIA can give immediate full relief and SBA spreads relief over 33⅓ years, it's well worth getting the split right. Maximise the qualifying plant and integral features going to AIA, and put the genuine structural cost through SBA. A capital allowances specialist or your accountant earns their fee here on a sizeable build.

The Capital Gains Tax Clawback — The Sting in the Tail

Here's the catch most people don't see coming. SBA you've claimed gets clawed back when you sell the building. The relief reduces your tax bill year by year while you own the property, but it effectively reverses on disposal.

Mechanically, the total SBA you have claimed is added to your disposal proceeds (or, equivalently, reduces your base cost) when you calculate the capital gain. So the SBA you enjoyed as income-tax or corporation-tax relief over the years comes back as an increased chargeable gain on sale.

This isn't a reason to skip SBA — relief now is generally worth more than tax later, and the rates differ — but it does mean SBA is best thought of as a timing benefit rather than a permanent giveaway. Factor the clawback into any decision to sell, and keep the figures so the gain can be computed correctly.

Record-Keeping

SBA depends on good records held over a long period — potentially decades. Keep:

• The allowance statement and the contract dates it's based on.
• A clear breakdown of qualifying construction costs, separated from land, plant, integral features and professional fees.
• The date the building was first brought into qualifying use.
• A running total of SBA claimed each year — you'll need it for the capital gains calculation on sale.
• Invoices and supporting documents for the original spend, retained well beyond the usual periods because the building may be held for many years.

Because SBA runs over 33⅓ years, the records you create at the start need to survive far longer than a normal tax year. Store them somewhere durable and make sure they pass to anyone who buys the building.

Worked Example: A £200,000 Workshop Build

Suppose your limited company builds a new workshop and the qualifying structural construction cost is £200,000 (after stripping out the land, integral features and professional fees, which are dealt with separately). SBA at the flat 3% rate gives:

• Annual SBA: 3% of £200,000 = £6,000 per year
• Relief continues at £6,000 a year for 33⅓ years until the full £200,000 is written off
• If the company pays corporation tax, £6,000 of relief reduces taxable profit each year

Say you claim SBA for 10 years and then sell. You'll have claimed 10 × £6,000 = £60,000 of relief. On disposal, that £60,000 is added back into the capital gains computation (increasing the gain / reducing the base cost), so the relief is clawed back at that point. You still benefited from the cash-flow value of ten years of relief along the way.

Quick Reference: SBA for UK Trade Businesses

SBA is a genuine relief on costs that used to get nothing — but it's slow, paperwork-dependent and clawed back on sale. If you're building, buying or fitting out commercial premises, talk to your accountant early so the cost split between AIA and SBA is right and the allowance statement is in place from day one. This article is general information, not tax advice.