Last reviewed: 4 September 2026. Product requirements are from the DESNZ Interim Product Specification version 2.0 (July 2026). Planning and building matters are signposted rather than advised on; we are publishers, not surveyors or electricians.
If you have a garden, a ground-mounted frame is usually the best plug-in solar decision available to you — and it is certainly the safest. It generates more than a vertical balcony rail because you can set a proper tilt, it needs no attachment to the building at all, it is trivially reversible, and it removes at a stroke the two questions that stop most installations: whether you may fix something to the wall, and whether the building’s cladding is on the prohibited list. What it does not remove is the mounting engineering. The specification requires a supplied mounting system with a structural analysis for UK wind and snow loads, and it expressly rules out the improvised alternatives — cable ties, rope, string, adhesive tape, bungee cords and straps.
Why the ground usually wins
Three reasons, in the order they matter.
- Tilt. A frame lets you set the panel at roughly 30 to 40 degrees facing south, which is close to the optimum for annual yield in Britain. A balcony rail forces 90 degrees, which our own calculator’s mounting factor puts at around 0.70 of a tilted array’s output. That factor is a declared estimate of ours, not an MCS table, and it is set out on the savings calculator.
- Nothing is attached to the building. The specification requires that any attachment method be reversible and non-permanent and that it must not compromise the structural integrity, fire performance or weatherproofing of the building. A free-standing ballasted frame on a lawn or patio does not engage that clause at all — which is why it is the mounting we recommend by default for tenants and leaseholders. See plug-in solar for renters.
- The fire clauses stop applying to a wall you are not touching. Clause 5.8 bans installation on aluminium and metal composite cladding, high-pressure laminate cladding, timber cladding and timber balconies, and on buildings undergoing external wall remediation. A frame five metres from the house sidesteps all of it.
The four places people actually put them
| Position | Our yield factor vs an optimally tilted array | Consent normally needed | The clause that governs it | Main risk |
|---|---|---|---|---|
| Free-standing ballasted frame on lawn or patio, ~30–40°, facing south | 1.00 | None, if you control the garden. Check the lease for tenants | cl. 5.5.1 mounting and structural analysis; cl. 8.3.2 ballasting for wind and snow | Wind uplift on an under-ballasted frame |
| Fixed to a fence or fence posts, ~20° or vertical | about 0.95 tilted, 0.70 vertical | Yours if the fence is yours; a boundary fence usually is not entirely | cl. 5.5.1; cl. 8.3.2 on not fixing to walls that form a boundary between dwellings | Fence posts are not designed for a sail; boundary disputes |
| On a shed or garage roof | up to 1.00 if the pitch and aspect suit | Yours, but see the timber question below | cl. 5.5.1 (permitted configurations); cl. 5.8 (surfaces) | Working at height; roof covering integrity; timber construction |
| Against a house wall at ground level, vertical | about 0.70 | None if free-standing and merely leaning is not the method | cl. 5.5.1; cl. 5.8 if fixed to the wall | Ventilation behind the module; cladding restrictions if fixed |
Wind, snow and ballast: the part that hurts people
An 800 W array is roughly four square metres of rigid, flat surface. In a February gale that is a sail, and the specification treats it as one. It requires manufacturers to demonstrate through structural analysis that the mounting system meets the loads for every mounting configuration they permit, with snow loads determined to BS EN 1991-1-3 and its UK National Annex and wind loads to BS EN 1991-1-4 with the UK National Annex and PD 6688-1-4. It also requires the documentation to state the maximum permissible installation height above ground level and the permissible heights based on wind effects for the loaded area, and to give information on fastening or ballasting depending on expected wind and snow load.
Practically, that means three things:
- Use the manufacturer’s frame and the manufacturer’s ballast figures. Not slabs you guessed at. If the documentation does not give ballast guidance, the kit does not meet clause 8.3.2 and that is a compliance question — see how to spot a non-compliant kit.
- Nothing improvised. Cable ties, rope, string, adhesive tape, bungee cords and straps are named and prohibited as mounting methods. They are also the single most common thing you will see in photographs of European balcony installations.
- Site it where a failure is survivable. The mounting must be designed so that foreseeable wind and snow loading does not cause detachment, instability or falling components capable of injuring anyone. Do not put it above a path, a play area, a neighbour’s garden or an escape route.
Sheds: the timber question
Clause 5.8’s prohibition list includes timber cladding systems and timber balconies. It is drafted for the external walls of dwellings, and a felted timber garden shed is not a dwelling — but it is precisely the construction the clause exists to worry about, with a combustible surface, a ventilated cavity and no compartmentation. [VERIFICAR: whether DESNZ intends the clause 5.8 prohibition on timber cladding to extend to detached domestic outbuildings such as garden sheds]. Until that is clear, our position is conservative: a free-standing frame beside the shed rather than a panel screwed to its roof, and if you do use the shed, follow the manufacturer’s list of surfaces on which installation is not permitted, which clause 5.5.1 requires them to publish.
The second shed issue is more mundane and injures more people: height. A shed roof is a working-at-height job on a structure that was not built to be walked on. If the answer to “how do I get up there safely” involves a garden chair, put the frame on the ground.
The cabling and the socket: where the real hazards are
A garden install is a garden electrical install, and this is the part where the specification is least forgiving.
- The socket must be a proper outdoor socket. Outdoor plugs and socket outlets require at least IP55 protection. Running a lead out of a window is not an alternative: extension cables, multi-way adaptors, RCD adaptors, travel adaptors and plug convertors are all prohibited. See extension leads and plug-in solar.
- Adding that socket is an electrician’s job. New fixed wiring outdoors is notifiable building work in England unless done by an installer registered with a competent person scheme; Wales, Scotland and Northern Ireland have their own regimes. Part P binds the person doing the work. See do I need an electrician.
- Cables are not to be buried or run in wet areas. The specification requires instructions on safe cable installation to reduce accident risk — pull relief, bending radii, and no installation in the ground or wet areas. A DC lead across a lawn is a mowing accident and a trip hazard; route it along a fence line with proper supports.
- Do not break DC connections under load. Switch off the AC supply first. Connectors must meet BS EN 62852, must be manufacturer-supplied matching pairs, and Y-connectors are not permitted.
- Lightning protection. If the building has a lightning protection system, the specification requires the separation distance from its down conductors to be observed, citing BS EN IEC 62305-3 (the document prints the number as 52305-3). This is rare on houses and common on blocks of flats.
Corrosion and the long game
A ground frame sits in wet grass for twenty years. The specification requires mounting materials to resist corrosion for the expected lifetime, requires fixings not to undermine that resistance, and requires materials to be chosen and assembled to prevent galvanic corrosion between dissimilar metals — with nylon washers or rubber isolators where needed. It also singles out marine, industrial and agricultural environments, with salt mist testing to BS EN 61701 and ammonia testing to BS EN 62716 where a product is offered for them. If you are near the coast or next to livestock, ask for those test results specifically; if the manufacturer says the product is unsuitable for corrosive environments, it must say so in the documentation.
Routine checks matter more on the ground than on a balcony, because a ground frame is easier to knock, mow into and grow over. The specification asks manufacturers to give recommended intervals for visual checks of fixings, cables and connectors — do them. See cleaning and maintenance and mounting a panel safely.
Frequently asked questions
Do I need planning permission for a panel in the garden?
Usually not, but a standalone array in a domestic garden in England has its own permitted development route with limits on size, height and distance from the boundary, and Scotland and Wales differ. Listed buildings and conservation areas are a separate question again. See planning permission for plug-in solar and listed buildings and conservation areas.
Can I put it on the flat roof of an extension?
That is a roof, and roof work is outside what a plug-in kit is designed for. Get a competent installer to look at it, and expect the answer to be a certified system rather than a plug-in one. See plug-in solar vs rooftop solar.
Does grass or a hedge growing up matter?
A great deal, and more than most people expect: partial shading on one module drags down output disproportionately, and a ground-level array is the easiest thing in the world to shade. Site it where the winter sun, not the June sun, still reaches it — see plug-in solar in winter.
Will it get stolen?
It is portable by design, which cuts both ways. Anti-theft fixings are a sensible ask, but they must not turn into a permanent attachment to a building you do not own, and they must not be the mounting method. Check whether your insurer treats garden equipment differently — see does plug-in solar affect home insurance.
Does a ground mount change the DNO notification?
No. It is the same device on the same connection: notify within 28 days, and notify again if you remove it. See how to fill in a G98 notification.
Primary sources.
DESNZ, Plug-in Solar Device Interim Product Specification version 2.0, July 2026 (PDF) ·
SI 2026/848 (legislation.gov.uk) ·
Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2 Part 14 ·
Approved Document P, electrical safety (England) ·
ENA, find my network operator.
General information, not legal or electrical advice. Adding an outdoor socket or any fixed wiring is work for a competent electrician working to BS 7671 — see our editorial methodology.