Solar Panels on a Garage Roof

Yes, you can put solar panels on a garage roof, and in all four UK nations it is normally permitted development. What changes is the small print: a garage is treated as "a building within the curtilage of a dwellinghouse", which is a different category from the house itself, with its own limits. In Scotland the difference is decisive, because a garage sitting forward of your front wall is excluded from permitted development altogether no matter how it looks.

The bigger obstacle is usually structural rather than legal. Most UK garages have a flat roof, a shallow mono-pitch, or a corrugated sheet roof, and none of those appear in the table of roof types the MCS standard tells installers to calculate from. That single omission triggers a mandatory clause that a lot of quotes quietly skip.

Below: the permitted development limits for each nation, the two MCS clauses that decide whether your garage needs a structural engineer, the asbestos check nobody is legally obliged to have done, the cable run and metering questions, and what the whole thing costs against putting the same panels on the house.

Do you need planning permission for solar panels on a garage?

Usually no, but the permitted development class that covers your garage is not the one that covers your house, and the limits are tighter in two of the four nations. Here is what each nation's own legislation says, checked today.

England

Class A of Part 14 of the Town and Country Planning (General Permitted Development) (England) Order 2015 permits solar PV or solar thermal equipment on, in its own words, "(a) a dwellinghouse or a block of flats; or (b) a building situated within the curtilage of a dwellinghouse or a block of flats". A detached or attached garage in your garden is squarely inside limb (b), and it gets the same numerical limits as the house.

Those limits were rewritten recently. The Town and Country Planning (General Permitted Development) (England) (Amendment) Order 2026 (SI 2026/896) came into force on 27 August 2026 and split the old single list into one set of rules for dwellinghouses and their curtilage buildings, and a separate set for blocks of flats. For a garage in the curtilage of a house, paragraph A.1(2) now says development is not permitted if:

• on a pitched garage roof, the equipment would protrude more than 0.2 metres beyond the roof slope, or the highest part of it would sit higher than the highest part of the roof, excluding any chimney;
• on a flat garage roof, the highest part of the equipment would be more than 0.6 metres higher than the highest part of the roof;
• on a wall, it would protrude more than 0.2 metres where that wall abuts a highway, or more than 0.4 metres in any other case;
• in a conservation area or World Heritage Site, it would go on a wall, balcony or roof enclosure that fronts a highway;
• the site is a scheduled monument, or, in the wording of A.1(2)(g), the equipment "would be installed on a dwellinghouse, or on a building within the curtilage of a dwellinghouse, if the dwellinghouse is a listed building".

Source: GPDO 2015, Schedule 2, Part 14, as amended by SI 2026/896.

Read that last one twice. In England it is the house being listed that removes the right, not the garage. A perfectly ordinary 1970s garage in the grounds of a listed cottage is out, and you need listed building consent plus planning permission.

There is also a condition, not a limit, that catches flat roofs. Under A.2(ba), a flat-roof installation on article 2(3) land, which includes conservation areas, requires you to apply to the council first for a determination as to whether prior approval is needed for the appearance of the equipment. That is an application, with a wait, even though the work itself is permitted development. A flat garage roof inside a conservation area therefore needs a trip to the council even though the work itself is permitted development, which is easy to miss when reading the height limits alone.

Scotland

Scotland is the one nation with a dedicated permitted development class for solar on a garage, and it is meaningfully stricter than the class for the house. Classes 6HA, 6HB and 6HC were inserted into the Town and Country Planning (General Permitted Development) (Scotland) Order 1992 on 24 May 2024 by SSI 2024/102.

• Class 6HA covers solar "on a dwelling" and allows the equipment to protrude up to 1 metre from the outer surface of an external wall, roof plane, roof ridge or chimney.
• Class 6HB covers solar "on a building situated within the curtilage of a dwelling", which is your garage, and allows only 500 millimetres. Half the allowance, for the same panels, on the same plot.

Class 6HB then adds a bar that has no equivalent anywhere else in the UK. Development is not permitted if "the building is situated in the front curtilage of the dwelling", and the class defines front curtilage as "that part of the curtilage of the dwelling forward of the principal elevation of the dwelling". There is no visibility test, no conservation area qualifier and no appearance judgement. If your garage stands forward of the front wall of your house, a common enough layout, solar on it is not permitted development and you need a planning application.

Class 6HB also removes the right where the building is a listed building or within the curtilage of one, or within a World Heritage Site. Source: Town and Country Planning (General Permitted Development) (Scotland) Order 1992, Schedule 1, classes 6HA to 6HC as inserted by SSI 2024/102.

Wales

The Welsh Government's own guidance sets out roof and wall mounted limits of 200mm projection and nothing above the ridgeline, and for flat roofs a different pair of numbers from England: panels "cannot be sited within 1 metre of the external edge of the roof" and "cannot protrude more than 1 metre above the plane of the roof". So Wales gives you more height on a flat garage roof than England does, and takes it back with a 1 metre setback from every edge, which on a small single garage removes a surprising share of the usable area.

Wales also writes a garage-specific conservation area rule that England does not have. Its guidance says that in a conservation area or World Heritage Site, "if panels are to be fitted to a building in your garden or grounds they should not be visible from the highway". That is a visibility test on the outbuilding itself, not the elevation test England applies. A garage roof that can be seen from the road can fail it even where the equivalent English installation would pass. Source: Welsh Government, planning permission for solar panels.

Northern Ireland

Part 2 of the Schedule to the Planning (General Permitted Development) Order (Northern Ireland) 2015 permits solar equipment on the roof of "(a) a dwellinghouse; or (b) any building within the curtilage of a dwellinghouse", and it is the most generous of the four on a flat roof: the limit is 1.5 metres above the plane of any flat roof, against 1 metre in Wales and 0.6 metres in England. The 20 centimetre projection limit applies only to a roof slope "which faces onto and is visible from a road", so a garage roof hidden behind the house is less constrained than the English equivalent.

Two Northern Ireland conditions are worth knowing. In a conservation area or World Heritage Site, equipment on a flat roof must not be visible from a road at all. And condition A.2(a) requires that "the primary purpose of the solar PV or solar thermal equipment would be to provide heat or energy for use within the curtilage of the dwellinghouse". A garage array intended mainly to export rather than to power the house does not sit comfortably inside that condition. Source: Planning (General Permitted Development) Order (Northern Ireland) 2015, Schedule, Part 2.

Northern Ireland also sits outside the Smart Export Guarantee. Ofgem states that SEG installations "must be located in Great Britain", so a Northern Ireland garage array earns nothing from the GB export scheme (Ofgem, Smart Export Guarantee). Our full four-nation breakdown is on the planning permission for solar panels page.

Does a garage roof need a structural engineer?

On most UK garages, yes, and the MCS standard says so in a clause worded as a "shall" rather than a "should". This is the part of a garage installation that gets skipped, and it is worth understanding before you read a quote.

MIS 3002, the standard every MCS certified solar installer works to, requires at clause 5.9.4 that "the MCS Contractor shall ensure that the roof structure is checked by a suitably competent person to ensure it can withstand the loads imposed by the solar PV system". Clause 5.9.5 then points the installer at Table 1 for the calculation method. Table 1 lists exactly four roof structures:

• roofs constructed from timber trussed rafters;
• traditional cut roofs from timber rafters and purlins, gable ended;
• traditional cut roofs with hips or valleys, where the table itself says consult a structural engineer;
• asymmetric duo-pitched roofs from rafters and purlins, where the table again says consult a structural engineer.

Now look at what an actual garage roof is. A concrete or timber flat deck. A shallow mono-pitch lean-to. Corrugated sheeting on light steel or timber purlins. A prefabricated concrete sectional garage. None of those is in Table 1.

Clause 5.9.6 then says: "Where the roof structure is in any way unusual, or there is any doubt whatsoever, a qualified structural engineer shall be consulted." Its note defines an unusual roof structure as any that "is not shown in the Table 1", shows signs of structural distress, shows signs of post construction modification, has a pitch "particularly shallow (i.e. less than 30° to the horizontal)", or has a design prone to snow build-up.

A typical garage fails that test twice over. It is not in Table 1, and its pitch is well under 30 degrees. So on a plain reading of the standard, a structural engineer is mandatory, not optional.

If the array will be ballasted rather than bolted down, which is the usual approach on a flat garage roof that you do not want to make holes in, clause 5.9.13(h) says it again independently: "A qualified structural engineer shall be consulted to ensure the roof is able to withstand the imposed load from both the solar PV system and the proposed ballast." Ballast is dead weight sitting on a roof that was designed to keep rain out, and the standard treats it as a separate load question from the panels.

For a mechanically fixed system on a solid deck, clause 5.9.12 asks for a condition survey and pull-out tests, and where the pull-out value cannot be reliably calculated, tests carried out to the Single Ply Roofing Association's "Site pull-out test protocol for flat roofs" (S15-19). Corrugated metal roofs get their own pair: clauses 5.9.9 and 5.9.10 require the sheet thickness and the way the sheet is fixed to the structure to be checked against the wind uplift the array introduces.

The practical version: if an installer quotes for a garage roof without anyone assessing the structure, they are not giving you a keen price, they are omitting a requirement of the standard they are certified against. Ask which of clauses 5.9.4, 5.9.6 and 5.9.13 they consider applies, and get the answer in writing. The same clause numbers appear as 3.9.x in the MIS 3002:2025 edition, so an installer quoting either numbering is reading the same rule. Source: MCS MIS 3002 Solar PV Systems, Issue 6.0, 18 March 2026.

Asbestos: the check nobody is obliged to have done

If your garage was built or refurbished before 2000, treat the roof as containing asbestos until someone competent says otherwise. Corrugated asbestos cement sheeting was widely used on garages and outbuildings in that era, and drilling, cutting or walking on it is precisely how fibres are released.

Here is the part homeowners get wrong. The Health and Safety Executive's duty to manage asbestos "covers: all non-domestic premises, like factories or shops" and the "common parts of multi-occupancy domestic premises, like purpose-built flats". Your own garage is neither. Nobody has ever been legally required to survey it, so the absence of a survey tells you nothing at all, and there is no register to check.

HSE also warns specifically about the physical risk, advising you to "take care not to walk on fragile material, for example asbestos cement roofs". An asbestos cement garage roof will not hold an installer's weight, which makes it both a fibre problem and a fall-through problem on the same afternoon. Sources: HSE, the duty to manage asbestos; HSE, find out if asbestos could be present.

If the roof is asbestos cement, solar is not impossible, but the sequence changes: the sheeting comes off and gets replaced first, by someone equipped to do it, and the panels go on the new roof afterwards. Price that as a re-roof plus an install, not as an install. The same logic we set out for solar panels and a new roof applies here, only with a disposal cost attached.

How many panels fit on a garage roof?

Fewer than you think, and on a single garage the roof is usually the constraint rather than your electricity use. Allow roughly 2 square metres per panel, the same figure we use throughout the site, and take off the edge zones before you start counting.

MIS 3002 clause 5.9.7 says modules "should not be mounted within 400mm from any edge of a domestic roof" unless specific measures are taken to resist the higher wind uplift in the edge zone, keep ridge tiles secure, protect rainwater run-off patterns and control snow shedding. On a house roof a 400mm border is a rounding error. On a garage roof measuring three metres by five and a half, a 400mm border on all four sides removes about a third of the area before a single panel is placed. In Wales the flat-roof setback is 1 metre, which removes considerably more again.

So measure the roof, subtract the border, divide by two, and you have your realistic panel count. On the example above that leaves room for about five panels, and a single garage will typically work out somewhere in the four to six range, which at current module wattages is roughly 1.8kWp to 2.7kWp. Using the MCS methodology range of about 800 to 900 kWh per kWp per year, that is somewhere near 1,400 to 2,400 kWh annually from a well-oriented garage roof. Useful, but not usually a whole household's electricity. Our panel count guide works the sum from the other direction, starting with your annual kWh.

Solar carports: the 9 square metre trap

In England, whether a solar carport is permitted development turns on whether the panels are on a building or are the structure themselves, and the difference is a hard 9 square metre cap.

If you put up a carport as a structure and then fit panels to its roof, the carport is dealt with under Part 1 Class E, which permits "any building or enclosure ... required for a purpose incidental to the enjoyment of the dwellinghouse", subject to limits: single storey, not forward of the principal elevation, buildings and enclosures covering no more than 50% of the curtilage excluding the original house, eaves no higher than 2.5 metres, and overall height no more than 4 metres for a dual-pitched roof, 3 metres otherwise, or 2.5 metres within 2 metres of a boundary. The panels then go on under Class A as a building in the curtilage, with no area cap at all.

If instead you erect a free-standing solar canopy, that is stand-alone solar under Class B, and Class B says the development is not permitted if "the surface area of the solar panels forming part of the stand-alone solar would exceed 9 square metres". At roughly 2 square metres per panel, 9 square metres is four panels, or about 1.8kWp. Class B also runs a height table for a dwellinghouse: 4 metres in general, 2 metres for any part within 5 metres of the curtilage boundary, 2 metres in a conservation area where it sits nearer the highway than the house does, and 1 metre where it is both within 5 metres of the boundary and forward of the principal elevation. An outright bar within 5 metres of the boundary applies only on a World Heritage Site. Note that the stricter list, which adds a one-per-curtilage limit and a 3 metre cap on any single dimension, is the one written for blocks of flats, not for houses.

Four panels will not shelter a car and charge one. That is why a serious domestic solar carport is normally built as a structure first and panelled second, and why quotes for "a solar carport" vary so wildly: some are pricing a building, some are pricing a canopy. Wales applies the same 9 square metre and 4 metre stand-alone limits, plus a 3 metre limit on any single dimension and a bar within 5 metres of the highway. Scotland's solar classes 6HA and 6HB are both written as equipment on a building, so a free-standing Scottish canopy should be checked with your council rather than assumed. Source for the England limits: GPDO 2015, Schedule 2, Part 1, Class E, and Part 14 Class B.

Wiring, metering and the DNO

A garage array is only worth having if its electricity reaches the house, and that depends on how the garage is fed. There are two situations and they are not equally good.

If the garage is fed by a sub-main from your house consumer unit, which is the usual arrangement for a garage inside the curtilage, the whole property is one connection with one meter point. Generation on the garage offsets consumption in the house exactly as if it were on the house roof, and the installer notifies your distribution network operator once, for the property. Our G98 and G99 guide explains which notification route applies and when it has to happen.

If the garage has its own supply and its own meter point, you have two premises as far as the grid is concerned. Electricity generated on the garage meter does not reduce the house bill, it offsets the garage's own consumption and exports the rest. Since Ofgem pays the Smart Export Guarantee on export meter readings, that export is paid at an export rate rather than saving you the much higher import rate you pay in the house. Establish which situation you are in before you get quotes, because it changes the economics more than anything else on this page.

The cable run itself matters too. A detached garage at the bottom of the garden means a longer run, and longer runs mean cable cost and voltage drop. It is a design question for the installer, not a deal breaker, but it belongs in the quote rather than as a surprise variation later.

What does it cost, and is a garage roof worth it?

Expect to pay more per kWp on a garage than on a house, mostly because the fixed costs do not shrink with the array. Scaffolding, the electrical work, the inverter, the DNO notification and the MCS paperwork cost roughly what they cost on a house, but you are spreading them over four to six panels instead of twelve. Our cost by system size page shows how sharply the per-kWp figure rises as systems get smaller.

Two things on a garage push the other way. The structural engineer's report is an extra line most house installs never see. And where the roof is asbestos cement, or a flat felt deck near the end of its life, you are buying a roof before you buy an array.

The VAT position, at least, is unambiguously good. VAT Notice 708/6 defines the relief at section 2.11 as covering "all systems that are installed in, or on the site of, a building", so an installation on your garage qualifies for the same zero rate as one on the house. That zero rate runs to 31 March 2027, after which supplies revert to the 5% reduced rate rather than the standard rate (VAT Notice 708/6). Our VAT on solar panels page has the detail on what is and is not included.

The honest summary: a garage roof is a good idea when it faces somewhere between south east and south west and your house roof does not, and a poor idea when it is simply the easier place to put scaffolding. Compare the two properly rather than assuming, because a bigger house roof with some shading can still out-generate a small clear garage roof, and sometimes it does not. If the garage genuinely has the better aspect, the orientation guide shows what that is worth in output, and are solar panels worth it puts the whole sum together.

What to ask before you sign

1. Which MIS 3002 clause covers my roof structure, and who is doing the check? If the answer is not clause 5.9.4 plus a structural engineer under 5.9.6 or 5.9.13(h), ask why not.
2. Was the garage built before 2000, and has anyone identified the roof material? No survey exists by default. Somebody has to look.
3. Is the garage on a sub-main from the house, or its own meter point? This decides whether you save at the import rate or earn at the export rate.
4. What is the usable roof area after the 400mm edge zone, and how many panels does that give? Get the number, not an estimate of your usage.
5. Which permitted development class and which nation's limits is the design working to? A Scottish garage forward of the house needs a planning application, not an assurance.