In-Roof Solar Panels: Cost, Pros & Cons
In-roof solar panels are set into the roof in place of tiles, so they sit flush instead of on rails above it. They look neater and need no bird-proofing, but produce a little less electricity. They make the most sense on a new build or when you are replacing the roof anyway.
Last updated October 2026
Fact-checked by John Rooney, Solar Energy Editor. Editorial policy
Quick Answer
In-roof (integrated) solar panels replace part of the roof covering and sit flush with the tiles. Hardware and labour cost roughly the same as on-roof panels (a 4 kWp on-roof system is £6,600–£8,500), but retrofitting to an existing roof costs more. They produce about 3–10% less electricity because they run hotter, and kit warranties are often shorter. They are best value on new builds and re-roofs.
How in-roof solar panels work
The installer removes the tiles or slates where the panels will go and fits a mounting and flashing kit to the battens. Standard-size panels clip into the kit, and flashing around the edges sheds water onto the tiles below, so the panels form part of the roof covering. Common UK kits include GSE In-Roof, Viridian Clearline Fusion, EasyRoof Evolution, GB-Sol and SolFit.
In-roof panels are different from solar tiles, which are small tile-shaped units that replace the whole roof covering. In-roof systems use ordinary panels, so they cost less and produce more per square metre than solar tiles.
In-roof vs on-roof solar panels
| In-roof | On-roof | |
|---|---|---|
| Where the panels sit | In the roof plane, replacing tiles or slates | On rails above the existing tiles |
| Looks | Flush and neat, close to a roof light | Raised, visible frame and gap underneath |
| Output | Usually 3–10% lower (less airflow, hotter cells) | Baseline |
| Weight on the roof | Lighter (about 10kg per panel) | Heavier (about 20kg per panel) |
| Bird-proofing | Not needed: no gap underneath | Often needed, an extra cost |
| Typical warranty | Kits often around 10–15 years | Panels often 25 years |
| Best fit | New builds, re-roofs, planning-sensitive homes | Existing roofs in good condition |
Output and weight figures from Sunsave and The Eco Experts; warranties vary by kit, so check the one in your quote.
How much do in-roof solar panels cost?
There is no fixed premium. Sunsave and The Eco Experts both put the hardware and labour roughly on par with on-roof panels, so a 4 kWp system starts from the same £6,600–£8,500 range. What changes the price is the roof you are starting with:
New build or re-roof: often cheaper overall
The panels replace tiles you would otherwise buy and fit, and the roofers' scaffolding is already up. No bird-proofing is needed.
Existing roof: usually more expensive
Tiles have to be stripped and the roof made good around the kit, which adds labour. On a sound existing roof, on-roof panels are normally the cheaper way to get the same output.
Ask installers to quote in-roof and on-roof side by side so you can see the difference for your roof.
Pros and cons of in-roof solar panels
Pros
- ✓ Flush, tidy look that blends into the roof
- ✓ No gap underneath for pigeons, so no bird-proofing
- ✓ About half the weight of on-roof panels
- ✓ Replaces tiles on a new or replacement roof
- ✓ Kits are tested for weathertightness, fire and wind (MCS 012)
Cons
- ✗ About 3–10% less electricity than on-roof
- ✗ Costs more to retrofit to an existing roof
- ✗ Kit warranties are often shorter than panel warranties
Are in-roof solar panels worth it?
Usually yes
Self-builds, new builds and homes having the roof replaced.
Often yes
Conservation areas or prominent roofs where looks matter. Check planning rules first.
Usually no
A sound existing roof where you just want the most output for the money: on-roof panels win.
In-roof solar on new builds
Manufacturers such as Viridian position roof-integrated panels as the preferred option for new-build roofs and roof replacements. In England, the Future Homes Standard regulations come into force on 24 March 2027 and add a requirement for on-site renewable electricity on new homes. Homes where work starts before 24 March 2028 under earlier applications are exempt.
Energy-saving materials fitted while a new home is being built are zero-rated for VAT, and residential solar installs are zero-rated until 31 March 2027. If you are self-building, get the solar installer involved before the roof is designed.
In-roof solar panel FAQs
What are in-roof solar panels?
In-roof (or roof-integrated) solar panels are fitted into the roof in place of some of the tiles or slates, using a flashing kit that keeps the roof watertight. They sit flush with the roof surface instead of on rails above it.
How much do in-roof solar panels cost?
Sunsave and The Eco Experts both put in-roof hardware and labour roughly on par with on-roof panels. A standard 4 kWp on-roof system costs £6,600–£8,500. Fitting in-roof panels to an existing roof usually costs more, because tiles have to be removed and the roof made good around the kit. On a new build or a re-roof you also save the tiles the panels replace and share the scaffolding.
Are in-roof solar panels less efficient?
Yes, slightly. With less air flowing behind them the panels run hotter, which reduces output. Estimates range from about 3% (The Eco Experts) to 5-10% (Sunsave) less than the same panels mounted on-roof.
Are in-roof solar panels worth it?
They are usually worth it when you are building a new home or replacing the roof anyway, or when looks matter, for example in a conservation area. On a sound existing roof, on-roof panels normally give more electricity for less money.
Do in-roof solar panels need planning permission?
In most cases no, on the same permitted development rules as on-roof panels. Listed buildings and homes in conservation areas may need consent.
Do in-roof solar panels leak?
A correctly fitted kit is designed to be watertight. Roof-integrated kits are tested for weathertightness, fire and wind resistance under the MCS 012 standard, so check the kit your installer uses is MCS 012 listed and that the workmanship warranty covers the roof.
Can I get the Smart Export Guarantee with in-roof panels?
Yes. In-roof systems installed by an MCS-certified installer get an MCS certificate in the same way as on-roof systems, which is what SEG tariffs require.
Is there VAT on in-roof solar panels?
Solar panels installed in homes are zero-rated for VAT until 31 March 2027, after which the rate is due to rise to 5%. Energy-saving materials fitted while a new home is being built are also zero-rated.
Will new homes come with solar panels?
In England, the Future Homes Standard regulations come into force on 24 March 2027 and add a requirement for on-site renewable electricity on new homes, which in practice usually means solar panels. Homes where work started before 24 March 2028 under earlier applications are exempt.
Related Guides
Solar Tiles
Solar roof tiles: costs, brands, tiles vs panels, and planning rules.
Viridian Solar
British-made Clearline in-roof integrated solar panels.
Installation Guide
What to expect from the installation process.
Flat Roof Solar Panels
Flat roof solar: costs, mounting systems, east-west layouts, and planning.
Solar Panel Cost UK
Full cost breakdown and payback periods.
Planning Permission
Permitted development, listed buildings, and when you need to apply.
Sources
- Sunsave, In-roof solar panels, sunsave.energy
- The Eco Experts, Integrated solar panels, theecoexperts.co.uk
- BRE, Roof product testing (MCS 012), bregroup.com
- HMRC, VAT on energy-saving materials (Notice 708/6), gov.uk
- MHCLG, Future Homes and Buildings Standards circular 01/2026, gov.uk
- Ofgem, Smart Export Guarantee generators, ofgem.gov.uk
John Rooney is the founder of Solar Info and has been covering the UK solar energy market since 2023. He researches every battery and inverter brand against manufacturer datasheets, MCS and Ofgem data, and feedback from the MCS-certified installers in our directory before publishing.
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