Solar panel installation in London

Serving London and the wider Greater London area, including Croydon, Bromley, Dartford.

If you own a London roof, read this before you get quotes

If you own a house or flat in London and you are weighing up solar, you are doing it in the most demanding installation environment in Britain. Not because the sun behaves differently over the capital — it does not — but because London stacks more planning authorities, more conservation areas and more scaffold logistics on top of the same basic job than anywhere else in the country. The Mayor’s target of 1 gigawatt of installed solar capacity by 2030, set through the London Environment Strategy, tells you the city wants your roof working. What follows is what actually happens between deciding to install and receiving your MCS certificate — specific to London’s housing, London’s 33 local planning authorities and London’s network operator.

One thing to settle immediately: the physics is fine. A well-oriented London roof sits comfortably in the upper half of the UK’s typical output range, and the installation process — survey, scaffold, fixings, wiring, commissioning, paperwork — is the same craft here as anywhere. The difference is everything around the process.

What London’s houses are made of, and why your installer must care

London’s housing stock is dominated by pre-1919 terraces to a degree few UK cities match. Victorian and Edwardian streets run for miles through Hackney, Lewisham, Haringey, Wandsworth and dozens of other neighbourhoods, and those houses share features that shape an installation:

Slate roofs with old fixings. The original Welsh slate on many inner-London terraces is over a century old, often on its second or third round of nail-sickness repairs. Fitting panels here means slate-specific roof hooks, careful dressing of each slate around the anchor, and a crew that has done it before — a team used to concrete interlocking tile can crack a distressing amount of slate while learning. Ask any London quoter how many slate roofs their fitters completed last year.

Butterfly roofs and parapets. Large parts of inner London — Islington, Camden, parts of Lambeth — have terraces with central-valley “butterfly” roofs hidden behind front parapets. These behave more like two small pitched roofs draining to a central gutter, and panel layout, access and drainage all need thinking through at survey, not on the day.

Rear additions and shallow back roofs. The classic L-shaped Victorian plan gives a rear addition whose roof is often the best unshaded, unseen slope — frequently the elevation a conservation officer prefers too.

Interwar semis in the outer boroughs. Move out to zones 4-6 — the 1930s streets of Barnet, Redbridge, Bexley, Harrow — and the stock changes to semi-detached houses with hipped roofs, usually re-covered in concrete tile at some point since the war. These are the most straightforward installs in London: standard hooks, decent rafter spacing, and driveways that make scaffold staging painless.

Flats and maisonettes. Roughly half of London households live in flats. Solar is genuinely possible on some — top-floor leaseholders with demised roof space, small blocks with cooperative freeholders — but it needs freeholder consent and often a licence for alterations before any survey money is spent. An honest installer says that up front rather than surveying first and disappointing later.

The installation consequence of all this: London quotes vary more than anywhere else in the country for legitimate reasons. Slate labour, parapet access, borough scaffold licences and conservation constraints are real cost lines, not padding.

Planning permission in London: national rules, 33 local gatekeepers

The starting position is the same as the rest of England: solar panels on the roof of a house are permitted development under Part 14 Class A of the GPDO, no application needed, and the geometry is precise: panels on a roof slope must sit within 0.2 m of the roof plane and below the ridge. The relaxation that arrived with SI 2026/896 (in force 27 August 2026) applies to wall-mounted panels, which may now project up to 0.4 m from the wall — 0.2 m where the wall fronts a highway.

London’s complication is who administers the exceptions. Planning in the capital is handled by 32 borough councils plus the City of London, each its own local planning authority, and London contains over 1,000 conservation areas — more than any other UK city by a wide margin. The pattern that catches people:

• Conservation areas such as Hampstead in Camden or the streets around Maritime Greenwich (a World Heritage Site) restrict what can happen on elevations visible from the street. Rear slopes usually remain workable; front slopes need checking, and sometimes an application.
• Article 4 directions — borough-level orders that remove specific permitted development rights — are common across London and vary street by street. The GLA itself confirms there is no central register; each borough publishes its own.
• Listed buildings always need listed building consent for panels, anywhere on the property, regardless of visibility.

The practical rule: never assume, check the borough. A competent installer confirms the planning position for your exact address at survey stage and gives it to you in writing. Where a conservation officer objects to on-roof panels, a flush integrated array fitted at re-roof time is often the alternative officers accept. For most London flat-roofed extensions, back additions and outriggers, a low-angled ballasted array within the 0.6 m height limit also stays within permitted development, and the design considerations are covered in our flat-roof solar installation guide.

UK Power Networks: the paperwork nobody mentions in the sales call

Every grid-connected solar system in London involves UK Power Networks — the distribution network operator that owns the cables in the street, not to be confused with whoever sends your bill. The rules are national but worth restating because getting the order wrong costs real money:

• G98 applies up to 16 A per phase — about 3.68 kW of inverter output. The installer fits the system, then notifies UKPN within 28 days of commissioning. Most modest London terrace systems can be designed to stay inside this.
• G99 applies above that — which includes most solar-plus-battery combinations. The application must be approved by UKPN before the system is energised, and approval can carry an export limit. Domestic-scale G99 typically takes weeks; larger or awkward connections take longer.

A London-specific note: dense urban networks mean UKPN occasionally imposes export limitation on G99 applications where local infrastructure is constrained. It is not common at domestic scale, but it is exactly the kind of thing that should surface at survey — an installer who promises unlimited export before the DNO has answered is guessing. If a battery is in your plan, the G99 application belongs at the start of the project, not after the hardware arrives.

The GLA, the London Plan and what the 2030 target does for you

London’s net-zero target year is 2030, the most aggressive timeline of any UK region, coordinated by the Greater London Authority through the London Environment Strategy. Two practical consequences for homeowners:

First, the London Solar Opportunity Map — built for the GLA by the UCL Energy Institute from aircraft LiDAR data — models the solar radiation falling on effectively every roof inside the M25, accounting for the slope of your roof and shading from neighbouring buildings and trees. It is free, public, and a genuinely useful sanity check before you invite anyone round: if the map shows your roof heavily shaded, ask hard questions of any quote that ignores it.

Second, the London Plan (Policy SI 2) expects solar PV on major new development across the capital. That has built a deep local supply chain of panels, mounting hardware and experienced labour — one reason London homeowners have more genuine installer choice than most of the country, alongside, admittedly, more lead-generation noise to filter out.

What a London roof actually generates

Honest numbers: a well-installed, well-oriented system in the UK typically produces somewhere between 850 and 1,050 kWh per year for each kWp installed, with the south of England toward the top of that band and the north toward the bottom. London and the South East sit in the upper half. A 4 kWp array on an unshaded south-ish London roof therefore has a reasonable expectation around the high-3,000s of kWh per year — but the honest figure for your roof comes from a shading survey and a yield model of your actual slopes, not from a postcode average. Be suspicious of any quote carrying a precise generation promise produced without either.

What installation costs in the capital

We do not publish invented London prices, because system size, roof type and access drive cost far more than geography. The anchors worth knowing: MCS-reported data puts the average installed price in England at roughly £1,565-£1,590 per kW as of spring 2026, and regional labour markets move real quotes 10-15% either side of national averages — London sits at the expensive end of that spread, driven by labour, parking and scaffold logistics rather than the hardware. Scaffolding itself typically accounts for £600-£1,200 of a domestic quote, and a borough highway licence adds cost where the scaffold must stand on the public pavement, as it must on most terraced streets. The full national picture — system sizes, what moves the price, and how to compare quotes line by line — is in our cost guide.

London postcode areas we cover

• E — East London: Hackney’s Victorian terraces, Stratford’s newer stock, Docklands flats
• EC — The City fringe: largely commercial, with pockets of residential conversions where freeholder consent rules
• N — North London: Islington and Haringey terraces, many with butterfly roofs behind parapets
• NW — Camden to Harrow: everything from Hampstead’s conservation streets to interwar Metroland semis
• SE — South East London: Greenwich, Lewisham and Southwark — big Victorian and Edwardian territory with generous rear slopes
• SW — South West London: Wandsworth, Lambeth and Merton terraces plus larger suburban roofs toward Kingston
• W — West London: Notting Hill’s stucco conservation streets through to Ealing’s 1930s avenues
• WC — Holborn and Bloomsbury: dense, historic, mostly flats — solar possible but consent-led

A worked London example

A typical install on an Edwardian terrace in SE London runs like this — treat it as an illustration, not a case study. Survey confirms the rear slope faces south-east, slate in fair condition, rafters at 400 mm centres. The borough confirms no conservation constraint on the rear elevation. Scaffold goes up under a pavement licence on day zero. On day one the crew fits slate hooks into the rafters — each fixing photographed before panels cover it — rails, then eight 450 W panels (3.6 kWp). The electrician runs DC cabling down through the loft to a 3.6 kW inverter in the cellar head, tests, and commissions. Staying under 16 A per phase means G98 applies: UKPN notified within 28 days, MCS certificate through about ten working days later, Smart Export Guarantee registration unlocked. Total roof time: one day. Total elapsed time from deposit: about five weeks, most of it scaffold scheduling and kit lead time.

London installation questions, answered directly

Do I need planning permission for solar panels on a London terrace? Usually not — rooftop solar on houses is permitted development in England, including London. The exceptions are real, though: conservation areas (over 1,000 of them in London) can restrict street-facing slopes, Article 4 directions vary borough by borough, and listed buildings always need consent. Check with your borough or have your installer confirm the position in writing at survey.

Who is the electricity network operator for London, and how long does approval take? UK Power Networks. For systems up to 16 A per phase (about 3.68 kW of inverter), there is no advance approval — the installer notifies UKPN within 28 days of switch-on under G98. Larger systems and most battery combinations need G99 approval before energisation, which typically takes weeks at domestic scale.

Do I need a licence for scaffolding on a London pavement? Yes — scaffold on the public highway needs a licence from the borough council, and on most London terraced streets there is nowhere else for it to stand. A professional installer arranges the licence as part of the job and builds the cost into the quote. If a quote for a terrace with no front garden shows no scaffold or licence line at all, something is missing.

Can I install solar on my London flat? Sometimes. A top-floor leaseholder with roof space demised in the lease, or a small block with a willing freeholder, can make it work — but freeholder consent and usually a licence for alterations come before anything else, and communal-roof projects need agreement across leaseholders. Get the consent conversation started before commissioning surveys.

Is the London Solar Opportunity Map accurate for my roof? It is a strong first check — the GLA and UCL built it from LiDAR aircraft data, so it models your actual roof slopes and real shading from buildings and trees. It is not a substitute for an on-roof survey, which also checks rafters, covering condition and your consumer unit, but if the map and a salesman’s shading claims disagree, believe the map until someone stands on your roof.

Nearby guides and next steps

Beyond the M25 we cover Reading, Luton and Oxford with the same installation-first approach. For the numbers behind any London quote, start with our cost guide — then, when you want a specific figure for your own roof, request a quote. No pressure, no same-day-discount theatre: a survey, a design, a written price, and you can stop at any step.