I’ve spent years on rooftops, filming and breaking down every stage of a solar build, and the first question every homeowner asks is simple are in roof solar panels worth it? These systems, also called roof integrated… photovoltaics (RIPV), seamlessly integrate into the roof itself instead of sitting on top of it like standard on roof solar panels. Brands like Vidian have built their own inroof solar mounting systems, and their sleek, best in class solar panels sit flush with the tiles for a modern look that many buyers see as a better choice for their home.
What Are In Roof Solar Panels?
In roof solar panels, also known as roof integrated photovoltaics (RIPV), work like traditional solar panels but sit inside the property’s roof rather than on top of it. The key difference between the two styles comes down to weight these weigh about 10kg, while standard panels weigh close to 20kg, so the lighter option puts less strain on the frame.
That lighter build comes with a trade off, though, and it shows up in the product warranty. Most in roof panels carry a 15 year warranty, while a standard warranty on regular solar panels usually runs for a full 25 years, and that gap matters given the high upfront cost of any setup.
How Do In Roof Solar Panels Work?
In roof and on roof panels both work through the same photovoltaic effect, turning daylight into usable electricity. The process stays identical whether the panel sits inside the roof or above it. What changes is the installation and the final appearance on the roof, not the science behind it. On roof panels get bolted above the tiles, while these integrated units sit flush within the roofline itself.
How Are In Roof Solar Panels Installed?
Every good installer starts with a roof that’s felted and battened tiles are stripped first, leaving a felt membrane and clean battens, with two trays per panel fixed on using a tray or pod system for stability.
Weatherproof flashing and lateral flashings then go in, working like a mini gutter to guide rainwater down through the roof gutter. An expanding foam strip and watertight seal keep the whole system leak free.
Some systems, like Vidian panels, differ the panel goes straight onto the battens, since each panel is 70mm thick, with the top 30mm and bottom 40mm frame doing the fixing work, and flashings slotting into the panel’s gaskets.
Every array also needs an inverter, with DC cables running from each panel through MC4 connectors to reach it. A poorly assembled connection can trigger an arc fault, so the connector sits inside a protective Arc Box with sealing grommets, ventilation and drainage ports to control temperature and moisture.
Benefits of In Roof Solar Panels
They win people over mostly on looks, giving better aesthetics and a flush installation that appeals to design conscious homeowners who want a clean appearance without bulky frames on show. If you’re replacing whole roof sections anyway, going with this option is genuinely cost effective, because the scaffolding you’ve already paid for cuts installation costs, and you skip extra mounting equipment altogether. There’s no extra bird proofing needed either, since pests can’t get under the panels to start nesting.
This built in bird protection saves real money too standard mesh bird protection or a premium bird system like solar skirt can cost you £1,000 on a large roof space, and that’s before counting the roof tile and labor savings you get from an integrated array.
Weight helps too this setup brings less weight to the structure, and its lighter build eases pressure on ageing rafters. Because it skips roofing hooks and roofing rails, you avoid wind uplift concerns entirely, which is a real bonus if your home sits in a windy area or out in the country.
Disadvantages of In Roof Solar Panels
No system is perfect, and in roof solar panels do carry lower efficiency, running around 5 10% less efficient than an on roof setup, which trims your energy savings over the year. The tight fit leaves less cooling space underneath, and since panels need ventilation to handle high temperatures well, that snugness is the main reason behind the drop. Retrofitting an existing roof also brings complex work and a costly bill, since someone has to handle existing roof tile removal first which is why in roof suits a new home build or a loft conversion far better than an older property.
You also lose some choice on layout with on roof kits you can mix portrait and landscape, use jumbo panels or standard size panels, and arrange the mounting system with real flexibility, but in roof systems don’t offer that same freedom.
It helps to understand the temperature coefficient behind the generation drop under standard test conditions, a panel gives 100% output, but by 75 degrees that output can fall to about 80%, translating to a 10 20% performance drop on a hot afternoon. Over a full year, though, that only shows up as a small dip on a weighted average basis.
Cost Of In Roof Vs On Roof Solar Panels
Let’s talk numbers, based on a typical 10 panel system. Scaffolding, wiring, and the inverter cost roughly the same whichever route you pick, so the price gap only opens up once you reach the mounting hardware.
Mounting Hardware Costs
Go with railing on an on roof system instead, and you’ll likely pay closer to £1,700, or around £30 per panel for bird protection through simple mesh, plus roughly £300 for the kit itself.
Total Installation Cost
All told, a typical in roof job lands near £9,695, against £8,995 for on roof though a slate roof or Rosemary tiles job can change those numbers since they often need extra parts that push up fitting times and costs.
Savings With Re Roofing
Factor in the re roofing cost too a typical semi detached house pays around £7,000 for a standard re roof, so going in roof at the same time could bring a genuine saving of roughly £700 versus doing the two jobs separately.
Insurance Backed Warranties for In Roof Solar Panels
Before you sign anything, ask about the insurance backed warranty on offer. If a roofing system develops a leak, or hooks fitted improperly cause a problem years later, manufacturer warranties usually only cover parts, not the scaffolding cost or replacement labor needed to fix things. That’s why an insurance policy sitting behind a workmanship warranty matters so much if your installer goes out of business, you can still make a claim and get the work put right.
In Roof vs On Roof Solar Panels Final Verdict
After years of standing on scaffolding in the cold, breaking down these systems panel by panel, my honest view is that there’s no single right answer between in roof and on roof solar. In roof solar panels win on looks, bird protection, and weight, and they make real financial sense if you’re already re roofing or building fresh. On roof wins on flexibility, panel choice, and slightly better cooling, and it usually costs less upfront if your roof isn’t being touched anyway.
FAQs in roof solar panels
What are in roof solar panels?
In roof solar panels sit flush within the roof structure instead of on top of it, replacing a section of the roof covering for a sleek look.
Are in roof solar panels more expensive than on roof panels?
Yes, they cost more upfront, but combining installation with a re roof can help save money overall.
Do in roof solar panels weigh less than standard panels?
Yes, around 10kg compared to 20kg for standard panels, so there’s less strain on the roof structure.
How long does it take to install in roof solar panels?
Slightly longer than on roof systems, since tiles must be removed and trays, flashings, and seals fitted carefully.
Do in roof solar panels need bird protection?
No, the flush design leaves no gap for birds or pests to nest underneath.
Can in roof solar panels be fitted on any roof type?
Most roofs work fine, though slate or Rosemary tiles may need extra parts, adding time and cost.
Do in roof solar panels perform as efficiently as on roof panels?
Not quite both use the same solar technology, but in roof panels run around 5-10% less efficient than on roof panels because they sit tighter to the roof with less airflow underneath for cooling. The gap shows up mostly on hot days, and over a full year it averages out to a small overall dip.
Is it worth choosing in roof solar panels over on roof panels?
Worth it for aesthetics, re roofing plans, or reduced weight. On roof is better if budget is the top priority.
