Solar installation day: exactly what happens, hour by hour

The decision to fit solar takes weeks. The installation takes one to two days. That gap surprises people, and so does how contained the disruption is: scaffold up a day or two before, a crew of roughly three on site, one short planned power cut, an hour of handover at the end. Clearline does not install anything; the work described here is what the MCS-certified installation team for your area actually does on a domestic retrofit. Knowing the sequence matters, because a homeowner who knows what good looks like can spot corner cutting while there is still time to challenge it.

The week before: scaffold, paperwork and kit

The paperwork is settled before anyone touches your roof. If the inverter is rated at 3.68kW per phase or less, the connection falls under G98: the installation team fits first and notifies your DNO within 28 days of commissioning, so nothing holds up the date. Larger systems need G99 approval in hand before installation, which typically takes 4 to 8 weeks, and an installation team that books your install before that approval exists is gambling with your deposit. The mechanics are in our G98 vs G99 guide; the point for install week is that this is entirely the installation team's job, and it should already be done.

Scaffolding goes up a day or two ahead of the crew, usually by a separate scaffold firm. For a solar job it typically costs £300 to £1,000 or more, around 13 per cent of the total install cost, and it should already be inside your quoted price rather than appearing as an extra. Expect it to stay up around two weeks in total, because the scaffolder collects it after the install rather than the same afternoon. The kit itself, panels, rails, inverter and any battery, arrives either with the scaffold or on the morning of the job, so leave space for a delivery and a works van.

Installation day, hour by hour

A typical domestic crew is a roofer plus two electricians, and most retrofits are finished within one to two days on site. A single aspect roof with eight to twelve panels is often one long day; two roof faces, a battery, or tricky cable routes push it into a second morning. The sequence below is a typical single day, and on a two day job the split usually falls between the roof work and the electrical work.

What the day needs from you

• Access, sorted the night before. Side gates open, the loft hatch clear with a metre of space around it, and the wall where the inverter and battery are going emptied.
• Parking. A works van and a kit delivery both need to get close. If parking is permit controlled or tight, warn the installation team in advance.
• Your wifi details. The inverter's monitoring needs your network name and password at commissioning. Have them written down; hunting for a router password at 4pm delays handover.
• A window for the power cut. If you work from home or have medical equipment that needs power, say so at the morning walk through so the AC connection is timed around you.
• An hour at the end. Handover is where you learn the shutdown procedure and get the app working. Be there for it, even if you were out all day.

What good workmanship looks like

You cannot inspect rafter fixings from the ground, but plenty of quality is visible before the scaffold comes down, and the time to raise it is while the crew is still on site.

• Tidy DC management. Cables on the roof clipped to rails or panel frames, not resting on tiles where they chafe and sit in water. Loft runs clipped, not coiled on the insulation.
• Labelled isolators. A DC isolator near the inverter and a labelled AC isolator by the consumer unit, so any electrician who visits in ten years can make the system safe without guesswork.
• Intact, seated tiles. No cracked tiles left in place, no brackets grinding on tile edges, and any penetration through the roof or wall properly sealed and weathered, not filled with a bead of mastic and hope.
• A ventilated inverter position. Inverters shed heat, and heat shortens their lives. A unit boxed into a sealed cupboard is a future fault, and our inverter lifespan guide explains why.
• Recorded test results. Commissioning readings written down and given to you, not just a thumbs up. They belong in your handover pack.

On kit, the packages the installation team installs are built around named hardware at published prices: LONGi Hi-MO X10 530W panels at £1,000 per kWp installed, with the Tesla Powerwall 3 from £6,350 installed where a battery is in the design, both at 0% VAT until 31 March 2027. A battery adds wall mounting and an extra commissioning step but rarely a whole extra day.

The paperwork that must arrive after

Dates per MCS, Sunsave and our G98 vs G99 guide, read 28 August 2026. Diarise the two week mark and chase anything missing.

The MCS certificate is the one that gates your money: no certificate, no SEG registration, no export payments. It also only exists if the business that installed your system was genuinely MCS certified, which is checkable in the public directory before you sign anything, as our installation team checking guide walks through.

Red flags, on the day and after

• No scaffold on a two storey roof. Working from ladders on a domestic solar job is a safety and quality shortcut in one.
• A G99 job booked with no approval. If the design is over 3.68kW per phase and the installation team cannot show the DNO's approval, the date should move, not the paperwork.
• Cracked tiles left behind. Tiles break during solar work; that is normal. Leaving them broken under the array is not.
• No commissioning results offered. An installation team reluctant to hand over test readings is telling you how much testing happened.
• Paperwork that never lands. An MCS certificate still missing weeks after commissioning blocks your export payments and is worth escalating in writing, first to the installation team, then to their certification body.