Cost & specification · checked 26 September 2026
Commercial Solar Carport Cost: The UK Figures That Exist
Search for commercial solar carport cost and you will be given confident per-kilowatt bands by companies that have not seen your ground conditions. This page does the opposite: it sets out the one published UK appraisal of a real car park, derives a per-kWp figure from it so you can check the arithmetic, then ranks the things that actually move the price — starting with the foundations, and including the parking you lose while it is built, which in the government's own example cost more than the canopy.
In short
- The one published figure: DESNZ costed an illustrative 80-space canopy at about £140,000 — roughly £1,000 per kWp on a derived 136 kWp.
- Foundations lead the price, and they cannot be priced before ground investigation.
- Lost parking can exceed the build cost — £180,000 against £140,000 in the same appraisal.
- No full expensing. Solar is special-rate plant: AIA on the first £1m, then a 50% first-year allowance.
- Enhanced Capital Allowances no longer exist — abolished April 2020, still quoted widely.
What a commercial solar carport is
A free-standing steel frame over parking bays, carrying solar modules above the vehicles. "Solar carport" and "car park canopy" describe the same class of structure; carport tends to be used for the smaller single-row installations and canopy for larger car parks, but there is no technical line between them. The format options are the same in both cases, and the bay layout decides which one fits:
Mono-pitch
One column line, deck sloping away from it, covering a single row of bays. Cheapest per kWp. Suits perimeter rows where the column line can sit against a boundary rather than in the aisle.
T-frame (double)
A central column line carrying a deck over two facing bay rows. The most bays covered per column and per foundation, so usually the best value on a large car park laid out in paired rows.
Cantilever
Columns at the rear only, deck projecting forward, nothing between vehicles. Chosen when the bay layout is fixed or manoeuvring is tight. Heavier steel and heavier foundations for the same covered area.
Sizing works from the bay count. A standard UK bay of 2.4 m by 4.8 m is about 11.5 m²; a 430 W module is about 2 m²; four modules per bay is realistic after allowing for beams, gutters, setback and maintenance access — roughly 1.7 kWp per space. The full sizing and yield arithmetic, with modelled output for ten UK cities, is on our car park solar canopies page.
The only published UK cost figure
When DESNZ consulted on requiring solar canopies on new car parks, it published an illustrative appraisal for an 80-space car park. The figures it used were approximately:
| Line | Figure |
|---|---|
| Installation | ≈ £140,000 |
| Annual energy saving | ≈ £28,000 |
| Annual EV charging revenue | ≈ £22,000 |
| Annual maintenance | ≈ £1,400 |
| Foregone parking revenue (3.5-month closure) | ≈ £180,000 |
Two things are worth taking from it. First, the derived unit cost: 80 bays at roughly 1.7 kWp is about 136 kWp, so £140,000 is in the order of £1,000 per kWp. That is a single illustration at a single size with the government's own assumptions — but it is a published figure with visible workings, which is more than any commercial per-kWp band on the market offers.
Second, and more important: the foregone parking was the largest number in the appraisal, larger than the installation itself. Any cost model that stops at the capital figure has omitted the biggest line. The proposal to require canopies was not taken forward — the government confirmed that on 21 May 2026 — but the appraisal stands as the clearest public worked example of a UK car park canopy.
What moves the price, in order
| Driver | Effect | Why |
|---|---|---|
| Foundations | Largest single variable | Pads, piles or ground screws, decided by ground investigation. Car parks are frequently on made ground and dense with buried services. A fixed foundation price quoted before ground data exists is a provisional sum. |
| Structural format | Cantilever costs most | A cantilever puts no columns between vehicles, which is sometimes the only option a bay layout allows — but the cantilever moment makes both the steel and the foundations heavier than a mono-pitch or T-frame covering the same bays. |
| Height | Drives the whole frame | Wind uplift governs the design of a large, light, exposed deck. Raising the clearance for vans or refuse vehicles increases loading, which feeds back into every member and every footing — and in England it can breach the 4 m Class OA limit and cost you permitted development. |
| Grid connection | Nil to very large | A G99 application is free to submit. If the network has no capacity at the point of connection, reinforcement is a different order of cost and time entirely, and it is the item most likely to stop a scheme. |
| Phasing | Adds to build cost | Keeping the car park trading means working in sections and remobilising plant repeatedly. Closing it is cheaper to build and costs you the parking instead — which in the one published appraisal was the bigger number. |
| Surface reinstatement | Visible on good surfaces | Each column base is a break-out and a make-good. Matching block paving, resin-bound or coloured surfacing is materially more expensive than patching tarmac. |
| Modules and inverters | Least interesting line | The commodity part of the quote and the part most sales conversations dwell on. Module price movements are small next to a change of foundation type. |
The practical consequence: commission the ground investigation before you accept a price, and get the G99 application in at the same time. Those two steps remove most of the uncertainty from a carport budget, and both can be done before committing to a structure. The sequence is set out on our solar panel canopies installation page.
Normalising three quotes onto one basis
The hardest part of pricing a carport is not getting quotes — it is making them comparable. Three suppliers will quote three different scopes and present them as the same thing. Before comparing any headline figure, force all three onto one basis:
- Is the foundation cost fixed or provisional? If nobody has seen ground data, every foundation figure in every quote is an estimate. A quote that says so is more honest than one that does not, and the honest one often looks more expensive for that reason alone.
- What grid scope is included? The G99 application, the DNO's own charges, any reinforcement contribution, the metering, and the AC works from inverter to distribution board. Reinforcement is the item most often excluded and the most expensive to discover late.
- What phasing is assumed? A price based on a closed car park is not comparable with one based on working section by section. Ask each supplier to state the number of bays out of use and for how long.
- Is surface reinstatement in scope, and to what finish? "Make good" means something very different on tarmac and on block paving.
- Which structural design is priced? A generic product range at a standard wind zone, or calculations for your site's exposure. If the latter is excluded, the price is provisional whatever it says.
- Is EV infrastructure included, excluded, or roughed in? Ducting and switchgear capacity for chargers that arrive later costs a fraction of retrofitting them.
- What is the unit? Compare cost per bay covered as well as cost per kWp. Bays are what you actually have; kWp is derived from them, and a supplier assuming a denser module layout will look cheaper per kWp while delivering the same canopy.
That last point matters more than it sounds. Two quotes at the same price per kWp can differ by a third per bay, because the modules-per-bay assumption is buried in the design. The evidence to demand from each bidder is listed on our solar canopy manufacturers page.
Whole-life cost, not capital cost
A canopy is a 25-year-plus structure carrying equipment with a shorter life than itself, so the capital figure is only the opening entry. Four items belong in the model:
- Maintenance and cleaning. DESNZ assumed roughly £1,400 a year for its illustrative 80-space canopy. A canopy sits at a shallow pitch, so rain clears soiling less effectively than it does from a steep roof and the cleaning interval matters more — covered on our solar canopy maintenance page.
- Inverter replacement. Inverters do not last as long as modules or steel. Budget at least one replacement cycle within the life of the array and check the warranty term separately from the module warranty.
- Structure and coating. Hot-dip galvanising to BS EN ISO 1461 is designed for decades outdoors, but coastal exposure and de-icing salt shorten that. Inspection of connections and base plates belongs in the O&M schedule.
- The parking, once. The construction-period loss is a one-off, but it is large: in the DESNZ appraisal it exceeded the build cost. It belongs in the capital appraisal rather than being treated as an operational inconvenience.
Against those, the recurring credits are the avoided import cost on the share of generation you consume on site, export revenue under the Smart Export Guarantee, any EV charging revenue, and the rates position — the generation plant stays out of the rateable value until 2035. Whether ownership beats a PPA depends almost entirely on how those recurring lines compare with a third party's unit price over the same term, which is why the answer differs by site rather than being a general rule.
The tax and rates position
Capital allowances. A carport bought outright is plant. The Annual Investment Allowance gives 100% relief on the first £1 million of qualifying expenditure in the chargeable period. Solar PV is special-rate plant, so it does not qualify for full expensing: expenditure above the AIA limit attracts a 50% first-year allowance, with the balance written down in the special rate pool. Models showing 100% first-year relief on a multi-million-pound scheme are wrong, and models citing Enhanced Capital Allowances are using a scheme abolished in April 2020.
Business rates. Qualifying on-site renewable generation plant is excepted from rating valuations until 31 March 2035. The land and settings remain rateable, above about 50 kW the supports and settings are valued, and no published guidance addresses how a carport's steel frame is treated — set out in full on our solar canopy business rates page.
EV charging. Chargepoint plant attracts a 100% first-year allowance to 31 March 2027, and the Workplace Charging Scheme contributes £500 per socket, up to 40 sockets per applicant, to the same date — with the education strand at £2,000 per socket. Detail on our EV charging under a solar canopy page.
Funding. For public sector bodies the position changed materially: the Public Sector Decarbonisation Scheme closed to new applications in November 2024 and no further window has been announced. Current routes are set out on our solar canopy grants and funding page.
Six claims to be wary of
| Claim you will see | What the source says |
|---|---|
| "Enhanced Capital Allowances give a 25% tax saving." | The Enhanced Capital Allowance scheme for energy-saving plant was abolished from April 2020. Any current quote or business case citing ECAs is working from pre-2020 material. |
| "A solar carport qualifies for 100% first-year relief." | Solar PV is special-rate plant and does not qualify for full expensing. The Annual Investment Allowance gives 100% relief on the first £1 million of qualifying expenditure in the chargeable period; above that a 50% first-year allowance applies, with the remainder written down in the special rate pool. |
| "Carports are permitted development under Class J, under 9 m ridge height." | Class J covers solar equipment on non-domestic buildings — a roof, not a free-standing carport — and the 9 m figure appears in no part of the right. A canopy above off-street non-domestic parking in England falls under Class OA, which requires prior approval and caps overall height at 4 m. |
| "Each bay holds 3 to 3.6 kWp." | A standard 2.4 m by 4.8 m bay is about 11.5 m². A 430 W module is about 2 m². Six modules fit on area alone and about four are realistic once beams, gutters, setback and access are allowed for — roughly 1.7 kWp per bay, not double that. |
| "Under 50 kWp is a simple G98 notification." | G98 stops at 16 A per phase, about 3.68 kW single-phase and 11.04 kW three-phase. Every commercial carport is a G99 application needing approval before installation. |
| "Payback is 3 to 5 years." | Payback is a function of the tariff you avoid, your self-consumption share, the foundation type and any parking revenue lost during construction. A single national payback figure cannot survive those four variables. |
Commercial solar carport cost: questions
How much does a commercial solar carport cost in the UK?
There is no reliable published price list, and any page quoting a narrow per-kWp band is presenting an estimate as a fact. The one transparent UK figure for a specific car park canopy comes from DESNZ, which used an illustrative 80-space car park at about £140,000 to install when it consulted on requiring canopies on new car parks. On a derived capacity of roughly 136 kWp for 80 bays, that implies something in the order of £1,000 per kWp — one illustration, at one size, with the government's own assumptions. Per-kWp cost generally falls with scale and rises with cantilever formats, high clearance, poor ground and phased working. Treat £1,000 per kWp as an order of magnitude for a straightforward mono-pitch on good ground, not as a quote.
What is the biggest hidden cost in a solar carport project?
Two, usually. The foundations, because they are priced before ground investigation and then repriced after it — which is why the ground survey should come before the quote, not after the order. And, on a car park that earns money or that staff depend on, the parking taken out of use during construction. In DESNZ's 80-space illustration, a three-and-a-half-month closure was costed at about £180,000 of foregone parking revenue against a £140,000 installation. The disruption was larger than the build.
Does a commercial solar carport need planning permission?
In England a canopy above off-street parking at a non-domestic site can proceed under Class OA of Part 14, introduced in December 2023. That is a prior approval route: the authority has 56 days to determine, glare is assessed in every case, and the limits include 4 m maximum height and 10 m from the curtilage of a dwellinghouse. Scotland has its own right, Class 9M, which excludes conservation areas. Wales has no canopy right — the Welsh stand-alone non-domestic solar right is capped at 9 m² of panels — so a Welsh carport is a full planning application.
What tax relief applies to a commercial solar carport?
For a corporation tax payer, the Annual Investment Allowance gives 100% relief on the first £1 million of qualifying plant expenditure in the period. Solar PV sits in the special rate pool and does not qualify for full expensing, so expenditure above the AIA limit attracts a 50% first-year allowance with the balance written down at the special rate. Separately, qualifying on-site renewable generation plant is excepted from business rates valuations until 31 March 2035, and chargepoint plant attracts a 100% first-year allowance to 31 March 2027. The abolished Enhanced Capital Allowance scheme does not apply to anything.
Is a carport worth it compared with rooftop solar?
Per kilowatt installed, no — a roof is a mounting structure you already own, and a carport is one you have to build on foundations you have to dig. The carport earns its place when the roof route is unavailable or too small: a weak or short-life roof, a leased or listed building, a roof already covered, or simply far more car park than roof. It also gives you control of pitch and orientation, covered parking, and a structure that EV charging can be built into from the start.
What standards should the structure meet?
Design to the Eurocodes with their UK National Annexes: BS EN 1990 for the basis of design, BS EN 1991-1-4 for wind actions and BS EN 1991-1-3 for snow loads, with steel design to BS EN 1993. Fabrication and erection to BS EN 1090-2, and hot-dip galvanising to BS EN ISO 1461 for outdoor design life. Site-specific structural calculations matter more here than on most structures, because wind loading is zoned and a canopy is a large sail — a generic product type-approval is not the same thing as a calculation for your location. Note also that products placed on the market in Great Britain carry UKCA marking; CE applies in the EU and Northern Ireland.
Sources
All checked on 26 September 2026.
- DESNZ — solar canopies on new car parks consultation (illustrative 80-space appraisal)
- HMRC — claim capital allowances and first-year allowances
- S.I. 2022/405 — renewables plant excepted from rating valuations
- S.I. 2023/1279 (Class OA) and GPDO Schedule 2 Part 14
- Energy Networks Association — G98 and G99 connection guides
- OZEV — Workplace Charging Scheme
- Using the UKCA marking
- European Commission PVGIS
This is general information, not engineering, planning or tax advice. This site is published by SEO Dons Ltd; we are not an installer.
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