Stay Warm InsulationCall

London & South-East England

Solar Panel Installation

Insulate first, then generate: solar PV arranged by the team that already knows your roof.

Get a free quoteCall 020 3411 1408
Accredited, certified installersOne point of contactFixed written quote

Is solar PV right for your home?

  • South, east or west facing pitched roofs with little shading
  • Homes with daytime electricity use, or a battery to shift use to the evening
  • Owners already booking EWI or loft work, where scaffold can be shared
  • Households planning an electric car or a heat pump
  • Landlords improving an EPC rating on a rented home

Solar Panels: key facts

  • A typical 4 kW system (10 to 12 panels) costs £5,000 to £8,000 installed, at 0% VAT until 31 March 2027.
  • A south-facing 4 kW system in London generates around 3,400 to 3,800 kWh a year.
  • Payback is usually 7 to 12 years, faster with a battery and an export tariff.
  • Installed by accredited MCS certified installers; MCS is what an export tariff requires.
  • Most pitched roofs are permitted development, so no planning application is needed.
  • Arranged and project-managed by Stay Warm, with a free survey and a fixed written quote.

What is solar PV?

Solar PV panels turn daylight into electricity you use in the home, with any surplus exported to the grid for a payment. A modern panel produces around 400 to 450 W, so a typical London roof takes 10 to 12 panels for a 4 to 5 kW system. Panels are fitted on rails above the tiles, an inverter converts the power, and a smart meter records what you export.

We are an insulation company first. Our advice is always to cut the heat loss before you generate power, because a well insulated home needs far less energy and a smaller, cheaper system. Once the fabric is right, solar is the next step, and many customers ask us for it after an external wall or loft job because we already know the roof, the scaffold and the house.

Stay Warm surveys the roof, checks orientation, shading and the fuse board, and gives you one fixed quote. An accredited, MCS certified installer fits the system. Where we are already insulating, sharing the scaffold saves money on both jobs.

Who does the work

Solar PV is arranged and project-managed by Stay Warm and installed by accredited, MCS certified installers. You get one point of contact, one written quote and one guarantee pack.

Solar Panels cost guide

Indicative 2026 market ranges for London and the South-East. Your fixed quote follows a free survey and depends on roof size, access and the equipment chosen.

Job typeIndicative cost
2 to 3 kW system (6 to 8 panels)£4,000 – £5,500
4 kW system (10 to 12 panels)£5,000 – £8,000
6 kW system (14 to 16 panels)£7,500 – £11,000
Add a home battery (5 to 10 kWh)£3,000 – £6,000
Bird protection, scaffold, upgradesItemised

VAT: 0%. Solar panels and batteries fitted with them are energy-saving materials, so the installation is charged at 0% VAT until 31 March 2027 (HMRC VAT Notice 708/6).

What a solar installation includes

Monocrystalline panels, typically 400 to 450 W each
String or hybrid inverter, sized to the array and any battery
Roof mounting rails and fixings suited to the tile type
DC and AC isolators, generation meter and consumer unit work
MCS certificate and DNO notification so you can claim an export tariff
Monitoring app so you can see generation and export

How solar installation works

1

Free survey

We check roof orientation, pitch, shading, tile condition and the electrical supply, and look at your electricity use.

2

Design and fixed quote

A system design with the number of panels, expected generation and a fixed written quote, usually within a few days.

3

Installation

An accredited, MCS certified installer fits the panels, inverter and wiring, normally in one to two days.

4

Commissioning and paperwork

The system is tested and switched on, and you receive the MCS certificate, DNO notification and warranties.

Free survey & fixed quote

Book a free, no-obligation survey and we will send a clear, fixed written quote. One point of contact from survey to sign-off, and a written guarantee on the work.

Get a free quote

Solar Panels FAQs

How much do solar panels cost in London?
A typical 4 kW system with 10 to 12 panels costs £5,000 to £8,000 installed. Smaller systems start around £4,000 and larger 6 kW systems run to £11,000. Adding a battery adds £3,000 to £6,000. VAT is 0% until 31 March 2027.
How much electricity will I generate?
A south-facing 4 kW system in London generates around 3,400 to 3,800 kWh a year, close to the average household use. East or west facing roofs generate 15 to 20% less.
Who installs the system?
An accredited, MCS certified installer. Stay Warm arranges the survey, design, quote and project management, and remains your single point of contact.
Do I need planning permission?
Not for most houses. Roof-mounted panels are permitted development if they do not stick out more than 200 mm from the roof surface. Listed buildings and some conservation areas need consent, which we check on the survey.
Should I insulate before adding solar?
Yes. Insulation cuts the energy the house needs, so a smaller system does the same job. If you are already having EWI or loft work done, we can share the scaffold and do both in one visit.
Is a battery worth it?
If you are out during the day, a battery stores the daytime generation for the evening and can also charge overnight on a cheap tariff. It adds £3,000 to £6,000 and typically improves the payback rather than extending it.
Are there any grants for solar panels?
For most homeowners there is no direct cash grant, but two things cut the cost. The installation is 0% VAT until 31 March 2027, which saves around £1,000 to £1,500 on a typical system, and the Smart Export Guarantee pays you for the electricity you export, typically £150 to £400 a year. Households on a low income or on certain benefits may qualify for a fully funded solar and battery system through the Warm Homes: Local Grant, which in London runs through your council. Our [solar panel grants guide](/guides/solar-panel-grants-2026) explains who qualifies and how to apply.

Areas we cover

We arrange solar PV across Greater London, Surrey, Kent and Hertfordshire. See all areas we cover →

Related services

Home Battery StorageAir Source Heat PumpsEV Charger InstallationLoft & Roof InsulationExternal Wall InsulationDouble & Triple Glazing

Related guides

In-depth, independent guidance to help you decide.

Solar panel grants 2026Solar panel cost in LondonAre solar panels worth it?Where homes lose heatInsulation cost guideLoft insulation guide

Last reviewed September 2026 by Stay Warm Insulation.

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