The short answer
Roof-mounted solar is the default for most homes: it uses space you already have, needs no land, is usually permitted development, and is the cheaper option because the roof provides the structure. Ground-mounted solar sits on a frame in your garden or field, which lets you set the ideal angle and orientation (south-facing, optimal tilt) for maximum output, avoid roof shading, and access the panels easily for cleaning and maintenance. The trade-offs are that ground mounts cost more (you pay for the frame, groundworks and cabling), take up land, and are more likely to need planning permission, since they have tighter permitted-development limits than roof panels. Choose roof-mounted if your roof is sound and suitable; choose ground-mounted if your roof is unsuitable or shaded and you have spare, sunny land.
Most UK homes put panels on the roof, but if your roof faces the wrong way, is shaded, or is structurally unsuitable, mounting panels on the ground is a real alternative — provided you have the land and accept the extra cost and planning steps. Here is how they compare.
Ground vs roof
- Roof-mountedUses existing roof
- Ground-mountedFrame on land
- CheaperRoof-mounted
- Best orientation controlGround-mounted
- Planning permissionMore likely for ground
Cost, orientation and output
Roof-mounted solar is cheaper because the roof already provides the supporting structure; you pay for mounting hardware, panels and the install, not for a separate frame or groundworks. The downside is that you are limited to your roof's existing angle and direction, so output depends on how well your roof happens to face the sun and whether anything shades it.
Ground-mounted solar costs more — you pay for a steel or aluminium frame, foundations or ballast, and a cable run back to the house — but it lets you set the optimal tilt and a south-facing orientation regardless of your roof, and to site the array clear of shading. That control can lift annual generation compared with a poorly oriented or shaded roof, partly offsetting the higher upfront cost on the right plot.
| Factor | Roof-mounted | Ground-mounted |
|---|---|---|
| Structure | Existing roof | Frame + foundations |
| Cost | Lower | Higher |
| Orientation / tilt | Fixed by roof | Set to optimum |
| Shading control | Limited | Site clear of shade |
| Land needed | None | Garden / field space |
| Planning permission | Often permitted development | More likely required |
| Maintenance access | Roof access | Easy, at ground level |
Indicative comparison for guidance. Sources: Energy Saving Trust; Planning Portal.
Planning permission and land
In England, roof-mounted domestic solar is usually permitted development and needs no planning permission, provided it meets the conditions on projection and siting (conservation areas and listed buildings have tighter rules). Ground-mounted solar has stricter permitted-development limits — there are restrictions on the size and number of standalone installations and how close they sit to boundaries — so a ground array is more likely to require planning permission. Always check with your local planning authority before proceeding, as the rules and thresholds vary.
Ground mounting also needs suitable land: an area of garden or field that is sunny, clear of shade, and large enough for the array, plus a sensible cable route back to the house. That makes it a natural fit for rural or larger properties and a non-starter for homes with small or shaded gardens. The land it occupies is then unavailable for other uses, which is a consideration on a tight plot.
Maintenance and which suits your property
Maintenance is easier on the ground. Cleaning, inspecting and servicing ground-mounted panels does not require roof access or scaffolding, which can make upkeep simpler and safer over the system's life. Roof panels are low-maintenance too, but any work needs safe roof access. Ground arrays do need secure siting and may warrant some thought about access by people or animals, depending on the location.
Roof-mounted solar suits the majority of homes: a sound, reasonably oriented, unshaded roof gives a cost-effective install using space you are not otherwise using, with no land taken and usually no planning permission. It is the default for good reason.
Ground-mounted solar comes into its own when the roof is unsuitable — wrong orientation, heavy shading, structural limits, or a listed building where roof panels are not wanted — and you have spare, sunny land. The ability to set the perfect angle and orientation, avoid shade and maintain at ground level can make it the better performer in those cases, despite the higher cost and likely planning step. Get an MCS-certified installer to assess both options for your property; for the Smart Export Guarantee, MCS certification is required either way.
Frequently asked questions
Is ground-mounted solar more efficient than roof solar?
It can generate more if your roof is poorly oriented or shaded, because a ground mount lets you set the optimal south-facing angle and site the panels clear of shade. The panels themselves are the same; the advantage is orientation and shading control. On a well-oriented, unshaded roof, roof-mounted solar performs just as well for less money.
Do ground-mounted solar panels need planning permission?
More often than roof panels. Ground-mounted arrays have tighter permitted-development limits — restrictions on size, number and proximity to boundaries — so they frequently require planning permission, particularly near boundaries or in sensitive areas. Roof-mounted domestic solar is usually permitted development. Always check with your local planning authority before proceeding.
Is ground-mounted solar more expensive?
Yes, usually. You pay for a frame, foundations or ballast and a cable run back to the house, none of which a roof install needs since the roof provides the structure. The higher cost can be partly offset where optimal orientation and no shading lift generation, but roof-mounted solar is the cheaper option for a suitable roof.
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.