If your roof needs replacing in the next year or two, installing solar panels and a new roof at the same time can save you thousands of pounds — primarily by sharing a single set of scaffolding instead of paying for it twice. But the saving only materialises if you get the sequencing right and collect the right quotes, so here's how to do that without being pushed into an expensive upsell.
Why does timing solar with a re-roof save money?
The single biggest overlap between a re-roof and a solar installation is scaffolding. Scaffolding a typical semi-detached house costs roughly £1,500–£3,000, and both trades need it. If you do the jobs separately — roof first, solar two years later — you pay that hire charge twice. Combine them into one project and you pay it once. That shared saving is typically £1,500–£3,000 in itself, and that's before you factor in reduced project management time and the fact that the new roof gives your solar installer a clean, known-condition surface to mount onto.
There's also a subtler reason. If you install solar now on a roof that needs replacing in a few years, you will eventually have to pay to have the panels removed and reinstalled so the roofer can get underneath them. Removal and reinstallation of a standard 10–16 panel system typically costs £1,200–£2,500 — on top of a fresh scaffold hire — making a roof in poor condition one of the most expensive mistakes a solar buyer can make. Our guide Do I Need to Replace My Roof Before Solar Panels? covers the roof-condition checks in detail.
Is it always cheaper to do solar and re-roofing together?
Usually, yes — but not automatically. You only capture the scaffolding saving if both trades are coordinating, ideally with the scaffold up for a single continuous period rather than two separate hires. The saving disappears if a roofer quotes the job with their own scaffold budget, and then a solar installer quotes separately with theirs, and neither knows the other is involved. The key is to tell both parties upfront what you are planning.
There are also situations where combining the projects doesn't make sense:
- Your roof is actually fine. If a qualified surveyor says your roof has 15 or more years left in it, there is no reason to replace it just to get a combined project discount. Install solar now on the good roof, and deal with re-roofing when the time genuinely comes.
- You want in-roof (integrated) solar tiles. These replace the roof covering rather than sitting on top of it, so re-roofing and solar genuinely become the same job. Costs and aesthetics differ significantly from standard on-roof panels — get a separate quote for each approach so you can compare fairly.
- The roofing work is minor. Replacing a few slipped tiles or repointing a chimney doesn't justify pulling solar quotes into the mix. The scaffold-sharing benefit applies to a full or substantial re-roof.
What does a combined re-roof and solar project actually cost?
The two jobs priced separately would typically look like this for a mid-sized home. A full re-roof on a three-bedroom semi commonly runs into several thousand pounds depending on materials and roof area. On top of that, MCS installation data shows that a typical 4kW solar panel system costs around £6,500–£8,500 fully installed in 2026, which already includes scaffolding, electrical work, and certification. When the two trades share a scaffold, you avoid a second hire of £1,500–£3,000 — which is where the combined-project saving comes from.
To put rough numbers on it: if you were going to pay £1,800 for scaffolding as part of your re-roof, and the solar installer would have charged a similar amount for theirs, sharing it once could realistically save £1,500–£2,500 on the total bill. That's not a guaranteed figure — it depends on your roof, your region, and how well the two trades coordinate — but it's the correct order of magnitude to use when deciding whether the timing makes sense.
One thing that genuinely does make combining the projects more urgent right now: solar panel installations currently attract 0% VAT under HMRC's VAT Notice 708/6 — meaning you pay no VAT on the panels, inverter, labour, and scaffolding as part of the solar contract. That relief runs until 31 March 2027, after which the rate is due to rise to 5%. On a typical £7,500 solar installation, getting it done before the deadline saves you several hundred pounds compared to doing it after. Our guide on 0% VAT on Solar Panels: What to Do Before March 2027 explains what's covered and what isn't.
How should you sequence the work?
Sequencing matters. The right order is: new roof first, solar panels second — in the same scaffold window. The roofer strips and relays the roof covering while the scaffold is up. Once the new tiles or slates are bedded in and signed off, the solar installer fits the mounting rails and panels. Both trades come down, scaffold is struck, and you pay for one hire. This is cleaner than it sounds if you plan it in advance.
The wrong order — panels on first, then roof — means the panels must come off again before the roof work can start, and you pay the removal and reinstallation cost on top of everything else. Never let a solar installer talk you into putting panels on a roof that you know needs replacing in the near future. That's how a project that should save you money ends up costing significantly more.
A practical note: give yourself enough lead time. Roofers in many parts of the UK are booked weeks or months ahead, and MCS-certified solar installers are in similar demand. Getting both to align on a shared scaffold window takes a little organising — but it's the kind of co-ordination that saves real money.
What questions should you ask installers before committing?
Before signing anything, make sure you get clear answers to these:
- Will your solar quote include shared scaffolding, or is it priced assuming a standalone install? Ask the solar installer to price on the basis that scaffolding is already in place from the roofer — if they won't adjust the quote, that's a red flag.
- Can you co-ordinate directly with my roofer? Some solar firms are happy to do this; others won't. The ones who will are usually the ones worth working with.
- Is your mounting system compatible with my new tile/slate type? Switching from concrete tiles to natural slate, for example, can mean new mounting rails at an extra cost of £300–£600. Get this confirmed in writing before the roofer orders materials.
- Are you MCS certified? MCS certification is required for your installation to qualify for the Smart Export Guarantee — the scheme that pays you for surplus electricity exported to the grid. You can check any installer's status for free at the MCS certified installer register. Our guide on how to check if a solar installer is MCS certified walks through the process step by step.
- What warranties apply, and do they survive removal and reinstallation? If panels need to come off for any reason in the future, you want to know your product warranty is still intact. Get this in writing.
When is combining the projects NOT worth it?
Being straight about this: if your roof is in genuinely good condition and has many years left in it, don't replace it just to unlock the scaffolding saving on a solar install. You'd be spending thousands on unnecessary roofing work. The combined-project logic only holds when re-roofing is something you were going to do anyway within the next few years.
Similarly, if your roof has specific complications — a listed building, a conservation area restriction, or an unusual material like hand-cut stone slate — the solar and roofing work can become genuinely complex, and rushing to combine them may mean you don't get the best outcome for either. Take time to get proper advice on both before deciding. Our guide on Solar Panels on a Slate Roof: Cost & Worth It? covers the specific issues with that material in detail.
The honest summary: if your roof needs replacing in the next one to two years, combining the projects is almost always worth exploring. If your roof is sound, install solar now and forget about a combined project for now — you'll be better off financially either way.
Getting quotes right for a combined project
The most important step is to get separate, itemised quotes from your roofer and your solar installer — and make sure each quote clearly shows what they are or aren't including for scaffolding. Then you can see exactly where the saving comes from and negotiate accordingly. Our guide on How to Compare Solar Quotes UK covers what to look for line by line, including the red flags that suggest a quote is hiding costs rather than showing them.
Getting at least two or three solar quotes is especially important for a combined project, because pricing on scaffold-sharing arrangements varies considerably. One installer might reduce their quote meaningfully when they know scaffolding is already in place; another might not budge at all. You only find that out by comparing.
If you'd like to see quotes from MCS-certified local installers who are used to working alongside roofers on combined projects, use FairSolar's free quote form to get no-obligation quotes from vetted installers in your area. There's no cost to you, and it's a good way to understand what a fairly-priced combined project should look like before you commit to anything.
Frequently asked questions
Should I get solar panels when I replace my roof?
Yes, in most cases it makes good financial sense. Installing solar panels at the same time as a re-roof means you only pay for scaffolding once instead of twice, with a typical saving of £1,500–£3,000. The key conditions are that the re-roofing is something you were already planning, and that both trades coordinate on a shared scaffold window.
Can you install solar panels at the same time as a new roof?
Yes. The standard approach is to complete the roof covering first while the scaffold is up, then have the solar installer fit the panels and mounting system before the scaffold comes down. This requires a little advance planning to align both trades, but it's a routine combined project for experienced installers.
What happens if I already have solar panels and my roof needs replacing?
Your solar panels will need to be removed before the roof work can begin, then reinstalled once the new tiles or slates are laid. This typically costs £1,200–£2,500 for a standard 10–16 panel system, covering scaffolding, labour, and recommissioning. It's a one-off cost and a good reason to get your roof properly assessed before installing solar in the first place.
Does the 0% VAT on solar panels apply if I'm also re-roofing?
The 0% VAT applies to the solar installation element of the project — panels, inverter, mounting system, associated labour and scaffolding — under HMRC's VAT Notice 708/6. It does not apply to the roofing work itself. The 0% rate runs until 31 March 2027, after which it is due to rise to 5%, so timing your solar installation before that deadline is worth considering.
Do I need to use the same company for the roofing and the solar?
No. Most homeowners use separate specialist trades — a roofing contractor and an MCS-certified solar installer — and simply coordinate them to share a scaffold. Some larger renewable energy firms do offer combined re-roof-and-solar packages, but getting itemised quotes from separate specialists and comparing them often gives you better visibility on where the money is going.