The short answer
Both generate electricity the same way, but they look and cost very differently. Conventional solar panels are mounted on rails a few centimetres above your existing roof covering — they are the most common, lowest-cost and most efficient option per pound spent. Solar tiles or slates (sometimes called a solar roof or building-integrated PV) replace the roof covering itself, so the photovoltaic surface is the roof. Tiles look far more discreet and can suit a new build, a re-roof, or a property where appearance or planning rules matter, but they typically cost considerably more per unit of power and can be slightly less efficient. For most existing UK homes wanting the best value, panels win; tiles make most sense when you are re-roofing anyway or appearance is the priority.
If you dislike the look of bolt-on panels, solar tiles are an appealing alternative that blends into the roofline. They come at a price, though. Here is how the two compare so you can judge whether the tidier look is worth the extra cost.
Panels vs tiles
- Conventional panelsMounted above roof
- Solar tiles/slatesReplace the roof covering
- Lowest cost per wattConventional panels
- Most discreet lookSolar tiles
- Best value retrofitConventional panels
Cost and output compared
Conventional panels are the mature, mass-produced option, so they offer the most generation for your money. They are quick to install on an existing roof and use efficient monocrystalline cells. For a straightforward retrofit on a sound roof, they give the best return per pound.
Solar tiles replace the roof covering, so you are paying for both a roof and a generation system in one. That integration costs more per unit of power, partly because the product is more specialised and partly because installation is more involved. Individual tiles are also smaller and can be slightly less efficient than full-size panels, so you may need more roof area to match the same output. The premium can be substantial, often well above the cost of an equivalent panel system.
| Factor | Conventional panels | Solar tiles / slates |
|---|---|---|
| How fitted | Mounted above roof on rails | Replace roof covering |
| Cost per watt | Lower | Higher |
| Efficiency | Higher | Similar or slightly lower |
| Appearance | Visible panels | Discreet, roof-integrated |
| Best for retrofit | Yes | Less cost-effective |
| Best for re-roof / new build | Possible | Strong fit |
| Install complexity | Lower | Higher |
Indicative comparison for guidance. Sources: Energy Saving Trust.
Appearance, planning and listed buildings
The main reason people choose solar tiles is looks. Because they form the roof surface rather than sitting on top, they give a flush, uniform finish that many find far more attractive than bolt-on panels, especially on a prominent front-facing roof. That discreet appearance can also help where planning sensitivities apply.
In England most domestic solar installations are permitted development and do not need planning permission, provided they meet conditions on projection and siting. But in a conservation area, on a listed building, or where panels would face a highway, the rules are tighter and a low-profile integrated system can be easier to get approved. Always check with your local planning authority, as the conditions vary and listed buildings generally need consent for any external change.
Durability, maintenance and which to choose
Both technologies are durable and long-lived, with the photovoltaic elements typically carrying performance warranties of around 25 years. Conventional panels keep the generation hardware separate from the weatherproofing roof beneath, which can make individual panel faults straightforward to diagnose and address. Solar tiles integrate generation and weatherproofing, so the product needs to perform both jobs reliably for decades, which is why choosing an established system and a competent installer matters.
Maintenance for both is light — occasional cleaning and inverter checks — and both should be installed by an MCS-certified installer to qualify for the Smart Export Guarantee and to meet building standards. The deciding factor is usually cost versus appearance. If you want maximum generation at the lowest price and you are comfortable with visible panels, conventional panels are the sensible choice. If you are re-roofing, building new, or appearance and planning push you toward an integrated look, solar tiles are a credible if more expensive alternative.
It is worth getting quotes for both on your specific roof, because the gap depends heavily on your roof size, shape and whether you need a new roof anyway. For a re-roof, the marginal cost of going integrated can be smaller than it first appears, since you would be paying for a new roof regardless.
Frequently asked questions
Are solar tiles less efficient than panels?
Slightly, in many cases. Individual tiles are smaller and can convert a little less sunlight per square metre than full-size monocrystalline panels, so you may need more roof area for the same output. The efficiency gap is modest, but combined with the higher cost it means tiles deliver less generation per pound than conventional panels.
Do solar tiles cost more than panels?
Yes, usually considerably more per unit of power. You are paying for a roof covering and a generation system combined, plus a more involved installation. The premium is most justified when you are re-roofing anyway or when appearance and planning rules make integrated tiles the practical choice.
Do I need planning permission for solar tiles or panels?
In England, most domestic solar is permitted development and needs no planning permission if it meets the conditions on projection and siting. Conservation areas, listed buildings and roofs facing a highway have tighter rules. Integrated tiles can be easier to approve in sensitive locations because they are discreet, but you should always check with your local planning authority.
Sources & further reading
Figures on this page are typical UK ranges drawn from published sources and depend on your specific home. They are guidance, not a quotation or guaranteed saving.