Capital allowances on flat-roof solar
Solar is an asset — and it is tax-relieved
A commercial flat-roof array is capital plant, and a business within the charge to UK tax can claim capital allowances on it. That reframes the cost: a system priced around £600 to £900 per installed kWp is not just an energy saving, it is a deductible asset that reduces your taxable profit. The route matters, though, and it is widely misstated.
Which allowance solar actually qualifies for
| Relief | Applies to solar? | What it gives |
|---|---|---|
| Full expensing (100% FYA) | No — main-rate assets only | Solar is special-rate, so excluded |
| 50% first-year allowance | No — special-rate main pool route differs | Not the solar route |
| Annual Investment Allowance (AIA) | Yes | 100% relief up to the AIA limit, in year one |
| Special-rate writing-down allowances | Yes (on any excess) | A percentage of the balance each year |
Solar PV sits in the special-rate pool as an integral feature. That is precisely why it is excluded from full expensing, which applies only to main-rate plant. The practical route to relief is the AIA: it currently allows 100% relief on qualifying plant up to the annual limit in the year of expenditure, and anything above the limit attracts special-rate writing-down allowances over time.
Get it confirmed properly
This page sets out the general position honestly, but capital allowances depend on your company's tax position, the AIA limit in the relevant period, and how the expenditure is pooled — so the treatment must be confirmed by your accountant before you rely on it. We provide the itemised project cost your accountant needs, and we will never tell you solar qualifies for full expensing, because it does not.
Get an itemised cost for your allowances claim
Responds within one working day
- 1. Free desk feasibility from your meter data and roof, no obligation.
- 2. Site survey and a fixed-price proposal, itemised in writing.
- 3. Install and aftercare by MCS-certified engineers.
- MCS Certified
- NICEIC
- RECC
- TrustMark