Do you need planning permission to install a solar carport?

The single most common misconception we correct on site visits is that a solar carport needs a full planning application. For most commercial schemes in England, it does not. Since 21 December 2023 the great majority of car-park canopy projects fall under permitted development, and the process is a prior approval, not a planning permission. The distinction is not pedantry — it changes your timeline, your risk and, occasionally, whether a scheme is viable at all.

This guide sets out what the rules actually say across England, Scotland, Wales and Northern Ireland, and where the real bottleneck sits (spoiler: it is rarely the council). It is written for the facilities managers, estates teams and finance directors who tend to get a very different story from whoever knocked on the door last.

Prior approval is not full planning permission

Full planning permission means the local planning authority (LPA) weighs the whole proposal on its merits and can refuse it on broad grounds. Prior approval is narrower and faster: the principle of development is already accepted in law, and the council may only assess a defined shortlist of matters. If they do not respond within the statutory window, approval is deemed to be granted. That is a materially better position to be building a project on.

For non-domestic solar carport installation in England, the relevant right is Class OA of the General Permitted Development Order, introduced by the December 2023 amendment specifically to make canopy-mounted solar over off-street parking easier to deliver.

England: Class OA prior approval

What the council can and cannot consider

Under Class OA the LPA’s assessment is limited. The matters they can weigh are:

• Siting — where on the site the structure sits.
• Design — the form and construction of the canopy.
• External appearance, including the effect of glare and glint on neighbouring uses, roads and, where relevant, aviation.

That is the list. The council cannot reopen the question of whether solar over parking is acceptable in principle, because Parliament has already decided it is.

One point that is routinely misreported: sustainable drainage (SuDS) is not a prior-approval matter under Class OA. Managing surface-water run-off from the new canopy area is instead a mandatory condition attached to the permitted development right. In plain terms, you do not have to persuade the council on drainage to get approval, but you are legally required to manage run-off as a condition of building. A competent installer designs the drainage in from the start; it should never be treated as an afterthought.

The Class OA limits in full

The right applies where the scheme stays inside these boundaries:

• Maximum height of 4m for the canopy structure.
• The canopy must be more than 10m from any dwelling (the house next door, not your own commercial building).
• Listed buildings and scheduled monuments are excluded, along with a small number of other sensitive designations. Sites with those constraints fall back to full planning.
• The LPA has a 56-day determination period. If they neither grant nor refuse prior approval within 56 days, you may proceed.
• Once prior approval is granted (or the site is confirmed as not needing it), the installation must be completed within three years.

Stay within those limits and a typical car-park scheme — including one covering an entire car park across multiple rows of bays — is deliverable under Class OA.

It is a standing right, not a closing window

Class OA is permanent legislation. It is not a grant round, a window that is closing, or a reason to sign anything under pressure. Anyone framing the current rules as a closing window is selling urgency, not solar. The only clock that matters is the three-year completion period that starts after your approval, and eight to twelve weeks of planning work is not the thing that will decide whether your project makes sense. Take the time to specify it properly.

Scotland, Wales and Northern Ireland

The permitted development picture is devolved, so the answer changes at the border.

• Scotland has its own equivalent: Class 9M permitted development covers solar canopies over parking on a similar basis. Scotland does not require full planning for these schemes as a matter of course — do not let anyone tell you it does.
• Wales (including Cardiff) currently has no direct equivalent to Class OA, so a commercial solar carport installation generally still needs full planning permission, assessed case by case.
• Northern Ireland likewise generally requires full planning permission for these structures.

Full planning is not a barrier — plenty of schemes secure it — but it is a longer, broader process with genuine refusal risk, so build the extra time and design engagement into your programme from day one if your site sits in Wales or Northern Ireland.

Domestic carports: Class E

The commercial rights above do not apply to a solar carport in the garden of a home. Domestic structures within the curtilage of a dwellinghouse sit under Class E permitted development, which caps the size of outbuildings and canopies. The height limits that most often bite are:

• Eaves height no more than 2.5m.
• Where any part of the structure is within 2m of a boundary, total height must not exceed 2.5m.

Exceed those and a domestic carport tips into needing full planning. Most of our work is non-domestic, but the residential caps are worth knowing if a homeowner or a mixed-use site is in scope.

Where the real delay lives: your DNO, not the LPA

Because Class OA turns planning into a 56-day prior approval in England, the planning stage is usually not the critical path. The longest single item on most commercial jobs is the grid connection.

Anything generating more than 3.68kW per phase — which is almost every commercial carport — needs G99 pre-approval from the Distribution Network Operator before it can be energised. G98 (fit and inform) only covers the smallest systems. G99 applications commonly take eight to sixteen weeks, and occasionally longer on constrained networks. If you take one scheduling lesson from this page, make it this: submit the DNO application early and in parallel with everything else, because it, not the council, is what tends to set your go-live date.

What this means for cost and funding

Planning route also feeds into the numbers. A carport is a more involved structure than a rooftop array — the steel frame alone is typically 40 to 50 per cent of the build — so expect roughly £1,100 to £1,600 per kWp at scale (higher on smaller schemes), or in the order of £6,000 to £12,000 per parking space excluding VAT. That is around two to three times the per-kWp cost of a comparable rooftop system, which starts nearer £700 to £1,050 per kWp. We break the components down in full on the cost guide. Note that commercial pricing is quoted ex VAT: the 20 per cent is recoverable for VAT-registered businesses, and the 0 per cent rate applies to residential installations only.

The economics improve markedly when the carport also charges vehicles. The Workplace Charging Scheme contributes £500 per socket (up to 75 per cent of cost, up to 40 sockets, currently running to 31 March 2027), and pairing generation with on-site EV demand lifts self-consumption and shortens payback. Solar-only paybacks typically land around eight to ten years; adding charging and high self-consumption pulls that in. The current position on grants and allowances is set out on our grants and funding page.

On tax, solar PV is a special-rate asset. It qualifies for the Annual Investment Allowance (100 per cent on up to £1m of qualifying spend) and, for companies, the 50 per cent first-year allowance — it does not qualify for full expensing. Business rates on eligible plant are exempt in England to 31 March 2035, though not in Wales or Scotland. These reliefs are worth real money, but they interact with your wider position, so take your own tax advice before relying on any figure here.

Getting it right

The planning answer for most English commercial sites is reassuringly straightforward: Class OA prior approval, 56 days, complete within three years, no full application. The work is in specifying the structure, designing drainage in from the outset, and getting the DNO application moving early. If your site is in Wales or Northern Ireland, plan for full permission and a longer runway. You can see the sectors we install for on our verticals page.

If you would like a straight answer on which route your specific site falls under, and a fixed-price scheme designed to the rules above, request a quote and we will map the planning and grid path alongside the numbers.