How long does it take to install a solar carport?

Ask an installer how long a solar carport takes and the honest answer has two numbers. There is the time a crew spends on your car park — usually one to three weeks for a commercial system, two to five days for a domestic one. And there is the calendar time from first survey to energised handover, which for most commercial projects runs two to three months. Confusing the two is how buyers get disappointed. The steel goes up fast. Getting permission to build it, and permission to connect it, is what sets the clock.

This guide walks the real end-to-end programme for a solar carport installation, shows where the weeks actually go, and names the two items that decide whether you are commissioning in eight weeks or sixteen.

Two clocks: time on site versus time on the calendar

The mistake is to plan around the visible work. Foundations, steel and panels are the part you can see, and for a system covering a modest staff car park that phase is genuinely short. But the canopy cannot be ordered until the design is fixed, cannot be built until consent is granted, and cannot be switched on until your Distribution Network Operator (DNO) says so. Those approvals sit in the background from week one, and they are the true length of the job.

For a commercial installation, budget roughly:

• Survey and design: 1–2 weeks
• Consents and grid approval: 2–16 weeks, running in parallel with the above and with fabrication
• Steel fabrication and delivery: 6–10 weeks (made to order)
• On-site build: 1–3 weeks
• Commissioning and handover: a few days

Because several of these overlap, the total is not a sum. A well-run project lands at eight to twelve weeks. A project waiting on a slow grid connection can stretch past four months.

A realistic commercial programme, stage by stage

Weeks 1–2: survey, structural check and design

The crew measures up, assesses ground conditions and reviews your existing electrical supply and spare capacity. Foundations are the one thing you cannot value-engineer once you are on site, so intrusive ground surveys earn their place here. The design then fixes bay layout, canopy height, panel count, inverter position and cable routes. Nothing downstream can start until this is firm.

Weeks 2–16: consents and the grid — in parallel, not in sequence

This is the critical path, and a competent installer opens both fronts the day the design is signed off. In England, a car-park canopy usually falls under Class OA permitted development, which means prior approval rather than a full planning application (more on that below). The determination window is 56 days. Alongside it sits the grid application, which for most commercial systems means a G99 connection offer — commonly eight to sixteen weeks, and almost always the longest single item on the programme.

Run these two together and they define your earliest possible energisation date. Run them one after the other, or start them late, and they add months. This is the single biggest variable in the whole job, which is why our solar carport planning permission guide treats it as a project-management problem, not a form-filling one.

Weeks 6–12: fabrication and delivery

Solar carport steel is fabricated to order, not pulled off a shelf. The structure is a large share of the total spend — steel alone is typically 40 to 50 per cent of the project cost, which is a big reason a carport runs roughly two to three times the price per kilowatt of an equivalent rooftop array. Lead times move with the steel market and the fabricator’s order book, so lock your design early to get your slot in the queue. The cost breakdown explains where the money goes and why per-space pricing sits around £6,000 to £12,000 ex VAT for a typical bay.

The on-site build: one to three weeks

Once steel and approvals are in hand, the visible work is quick:

1. Groundworks and foundations — excavation, pile or pad foundations, curing time.
2. Steel erection — columns and beams craned and bolted into place.
3. Canopy and panels — purlins, mounting rails and modules fitted.
4. Electrical first fix — DC cabling, then AC, inverters, isolation and metering.
5. Snagging — a walk-round against the design before the DNO attends.

A compact system on good ground can be mechanically complete in a week. A larger array covering an entire car park, or one on difficult ground with a live surface to work around, sits at the top of the one-to-three-week range. Our note on how solar carports are installed covers each of these steps in detail.

Commissioning and handover

The DNO witnesses or is notified of the connection, the system is tested and energised, and you receive the handover pack: electrical certificates, the operation and maintenance schedule, and monitoring access. For a G99 connection there can be a short wait for the operator to attend, so factor a few days here rather than assuming same-day switch-on.

The two items that set your timeline

Planning: prior approval, not a full application (England)

Since 21 December 2023, Class OA of the General Permitted Development Order has given a standing right to install solar canopies on off-street car parks in England. It is prior approval, not full planning permission: the council can only consider siting, design and glare, and must determine within 56 days. Managing surface-water run-off through a sustainable drainage system (SuDS) is a mandatory condition of the right, not one of the matters the council weighs in the prior-approval decision — a distinction worth getting right in your application.

The main limits: the canopy must be no more than 4 metres high, sit more than 10 metres from any dwelling, and the right excludes listed buildings and scheduled monuments. The installation must be completed within three years of approval.

Because this is a permanent, standing right rather than a scheme with a closing date, there is no reason to rush a purchase on the strength of it. Plan around the 56-day window; do not let anyone sell you a fast-expiring version of a right that is not going anywhere.

England is the straightforward case. In Wales (including Cardiff) and Northern Ireland, full planning permission is generally still required and assessed case by case, so add time for a standard application. Scotland has its own Class 9M permitted development route for solar canopies, so it is not the full-planning path either.

The grid connection: usually the long pole

Your DNO governs how, and how quickly, you can connect. A very small system exporting no more than 3.68 kW per phase can use the G98 fit-and-inform process — connect first, notify after. Almost every commercial carport is larger than that and needs G99 pre-approval, where the operator studies the local network before issuing an offer. That study commonly takes eight to sixteen weeks, which is why it so often dictates the finish date. Apply the moment your design is fixed, and always work to the terms your own regional DNO sets rather than a generic figure.

Domestic versus commercial: why the gap is so wide

A home solar carport is a different animal. On-site works are typically two to five days, planning is often simpler, and a modest single-property system may sit within the G98 route rather than needing a full G99 study. Residential installations also currently attract 0% VAT until 31 March 2027 (reverting to 5% after that), whereas commercial projects are quoted ex VAT — the 20% is charged but is normally recoverable by a VAT-registered business. Fewer approvals and a smaller electrical scope are what compress a domestic timeline into days rather than months.

Phasing a live car park

Most commercial sites cannot close the whole car park for three weeks, and they do not have to. A sensible installer sequences the work in blocks — foundations in one section while another stays open, then steel, then panels — so a proportion of bays remains usable throughout. This adds a little to the on-site duration but keeps the site trading. Agree the phasing plan, traffic management and any out-of-hours working before the crew arrives, not on day one.

Adding EV charging — does it change the timeline?

Combining the canopy with chargepoints is common, and it barely moves the structural programme; it mainly adds electrical scope and, sometimes, more grid capacity to arrange with the DNO. It can also bring the Workplace Charging Scheme into play — a grant of £500 per socket (up to £2,000 for state-funded education), covering up to 75% of costs, capped at 40 sockets, available until 31 March 2027. The one timeline effect worth flagging is that extra load may enlarge your grid application, so raise EV plans at design stage rather than bolting them on later.

What you can control

You cannot shorten a 56-day determination or a DNO study by wishing. You can, however, remove the self-inflicted delays that pad most projects:

• Start the grid application and prior approval on day one of a firm design — never after fabrication.
• Freeze the design early so steel can be ordered and your fabrication slot booked.
• Book intrusive ground surveys up front, because foundation surprises stop everything.
• Set realistic expectations internally — two to three months, not two to three weeks.

An illustrative well-run project might look like this: design signed off in week two, prior approval granted by week eight, a G99 offer accepted around week twelve, steel delivered in the same window, a two-week build, and energisation in week fourteen. That is a scenario, not a promise; your ground, your DNO region and your council will shift the numbers.

Tax treatment is worth a brief word for context: solar PV is a special-rate asset, so a company typically claims the Annual Investment Allowance (100% up to £1m) plus 50% first-year allowance on the balance, and business rates in England are exempt on eligible solar until 31 March 2035. It is not covered by full expensing, and the rules differ across the UK — take your own tax advice before you rely on any of it.

Want a realistic programme for your own site, mapped against your council and your DNO region? Get a solar carport installation quote and we will set out the timeline honestly, stage by stage.