How Are Solar Panels Installed? (Step by Step Process)

The exciting time from getting quotes, to switch on day.

If you’re just getting quotes, or you’ve paid a deposit and booked your install, you probably want to know what the process will look like. Most of the time is spent on picking your installer, waiting for paperwork and then a few noisy days on the roof.

Let’s see what the whole process looks like.

The short version

A rooftop install on a UK home follows the same shape whoever does it. You get a survey, the installer designs a system and quotes for it, scaffolding goes up, a small team spends one to three days fitting the mounting, panels, inverter and any battery, an electrician wires and tests the lot, and the system is commissioned and registered with your network operator. After that you sign up to an export tariff so you get paid for the electricity you send back to the grid.

The order rarely changes. What varies is the timeline, the roof-mounting method and the amount of electrical work, which is where the cost and quality differences show up.

Before anyone climbs on the roof

Get the run-up right and the roof work is almost boring, which is exactly what you want.

Checking whether you need planning permission

Most rooftop installs in the UK fall under permitted development, which means no planning application. The common exceptions are listed buildings, streets where the council has withdrawn those rights (an Article 4 direction), larger ground-mounted arrays and, in conservation areas, panels on a wall facing a highway. A decent installer checks this at the quoting stage rather than leaving you to find out. If your home is affected, allow an extra eight to twelve weeks for the council to decide.

The survey and system design

The survey is where the installer works out what your roof can take: its condition, pitch, orientation and shading, and whether there’s enough clear space. Most of this is now done remotely from photos or a video call, which is just as thorough for a straightforward roof. Hipped, vaulted and flat roofs usually still get an in-person structural check.

Orientation and angle drive how much you’ll generate. South-facing is the classic choice, though an east-west split can fit more panels and spread output across the day. It’s worth reading up on the best roof angle before you sign off a design, so you can ask sensible questions. The installer then sizes the array to your electricity use and roof space, and picks the hardware to match.

Two design choices matter here. First, the inverter, which converts the panels’ DC electricity into the AC your home uses; many 2026 installs use a hybrid inverter so a battery can be added later without swapping it out. Second, shade. If a chimney, tree or dormer shades part of the array, one shaded panel can drag down a whole string on a basic setup, so the design should include microinverters or power optimisers, which let each panel work independently.

The installation, hour by hour

Once the design is approved and any grid application is in, here’s the sequence a team works through.

How panels attach to your roof

This is the part homeowners worry about most, so it’s worth being specific. Panels are never screwed straight through your tiles. The load path runs from the panel into the clamp, into the rail, into a roof hook, and finally into the timber rafter underneath. The tiles simply sit back over the hooks.

On-roof versus in-roof

Most installs are on-roof: the panels sit a few centimetres above your existing tiles on rails. It’s quicker, cheaper and easy to service. In-roof (or integrated) mounting removes the tiles under the array and sets the panels flush into the roof surface, which looks neater and suits new builds. It costs more and needs careful flashing to stay watertight, so it’s a choice to weigh up rather than a default.

Tiles, slate and watertightness

Standard concrete or clay tiles lift easily to seat a roof hook. Slate is more brittle and often can’t rest on a hook without cracking, so the installer cuts a small recess or uses a slate-specific bracket, then beds everything back down. Cables pass through the felt membrane under your tiles between overlapping sections, so nothing is torn. Understanding how the panels stay fixed makes it easier to judge whether a team is being careful.

Testing, sign-off and grid connection

The system isn’t finished until it has been tested, certified and registered with your electricity network. This is the paperwork that protects you and gets you paid.

MCS certification

A domestic install should be certified under the Microgeneration Certification Scheme, or the equivalent Flexi-Orb scheme. The certificate confirms the work meets the standard and is what suppliers ask for before they’ll put you on an export tariff. The electrical work also has to comply with the wiring and building regulations that cover electrical work in the home.

G98, G99 and your network operator

Every grid-connected system has to be declared to your Distribution Network Operator, the company that runs the local cables, and the route depends on size. An inverter rated up to 3.68kW per phase falls under G98, a simple notification sent within 28 days of switch-on. Anything larger needs a G99 application, submitted and approved before connection, so the operator can check the local network can absorb your exports. A good installer handles the whole DNO application for you. Fast-tracked domestic applications come back in around ten working days, though a standard G99 application gives the operator up to 45 working days.

What the installation actually costs

Headline system prices bundle everything together, which hides how much of your money goes on the install rather than the kit. For a typical 4kW system in 2026, panels and inverter are only a little over half the bill; mounting, scaffolding, labour and certification make up the rest. Here’s a realistic breakdown for a standard two-storey home with panels and a hybrid inverter, no battery.

Add a 10kWh battery and the total typically lands between £9,500 and £12,000, since the battery is the single biggest line item. For a fuller picture of hardware pricing and system sizes, see our guide to what solar panels cost. Two things push the number up more than most people expect: the roof and the region.

Where you live matters too. Installer labour rates in London and the South East run well above those in the North East, Yorkshire or Wales, so an identical system can vary by a thousand pounds or more across regions. Three quotes on the same specification is the only way to know you’re paying a fair rate.

After the switch-on

Once the system is live, two jobs remain, and one of them pays you.

Registering for an export tariff

With your MCS certificate in hand, you can sign up to a Smart Export Guarantee tariff and get paid for surplus electricity you send to the grid. Your chosen supplier asks your network operator for an export meter number, which takes one to four weeks, after which you submit a reading and payments begin. Rates vary widely between suppliers, so compare before you commit.

Monitoring and maintenance

Solar needs little upkeep, but it isn’t fit-and-forget. The monitoring app is your early-warning system: a panel or string producing far less than its neighbours points to a fault worth investigating. An occasional visual check from the ground after big storms, and a clean every few years if your panels are shallow-pitched or under trees, is about the extent of it.

Flat roofs, ground mounts and barns

The process shifts when the location changes.

On a flat roof, drilling is usually avoided to protect the waterproof layer, so panels sit on a ballasted frame weighted down against wind. That adds a lot of weight, around 80kg per panel, which is why flat-roof arrays are more common on commercial buildings with strong decks. Panels are also tilted and spaced so they don’t shade each other, which limits how many fit.

A ground-mounted array skips scaffolding but needs a proper foundation, either concrete footings or driven posts, plus a mounting frame. Beyond a few panels it needs planning permission, and more open, unshaded land than most households have. Barns and outbuildings can work well if the roof is sound and the inverter sits inside, keeping cable runs short.

Can you install solar panels yourself?

You can buy the parts, but a full DIY install is a poor idea for most people, and not mainly because of the roof work. The electrical connection must be done by a qualified person and certified, and a self-installed system is very unlikely to gain MCS or Flexi-Orb certification. Without that certificate you can’t claim an export tariff, which removes a large chunk of the financial case, and you forgo the workmanship warranty and paperwork an insurer or future buyer will ask for. Add the risk of working at height with live DC cabling, and the sums rarely favour going it alone.

How to prepare, and red flags to watch

You don’t need to do much before install day, but a little preparation keeps things smooth.

• Clear access to your loft, fuse box and meter. The team will need clean routes between them.
• Move cars off the drive. Scaffolders and the delivery van need the space.
• Have your wifi password ready. The system connects to the internet during commissioning.
• Be home for the start of day one. You’ll agree the cable route and battery location in person.
• Save the paperwork somewhere findable. The MCS certificate and design drawings matter when you sell or claim.

Just as useful is knowing what a good and a bad job look like from the ground.