The safest rule

Do not ask only, “What is the price?” Ask, “What exact work is included in this fixed price, what is provisional, and what could change after the technical survey?”

Most so-called hidden solar costs are not secret charges. They are differences in scope. One installer includes scaffolding, electrical upgrades and certification; another advertises panels and labour, then prices the rest later. The cheaper quote may still be good, but only after both offers are normalised.

What a complete solar quote should show

The Renewable Energy Consumer Code says member companies should provide a proposal containing performance and financial estimates plus a detailed written quotation before the contract is signed. Its consumer guidance also recommends an all-inclusive breakdown and a performance estimate specific to the property.

At minimum, look for:

  • system capacity in kWp and the number and model of panels;
  • inverter model, quantity and rated output;
  • battery model, usable capacity and power, if included;
  • mounting system and array layout;
  • annual generation estimate, shading factor and key assumptions;
  • scaffolding or other roof-access arrangements;
  • electrical work and monitoring equipment;
  • grid-notification or application responsibilities;
  • MCS certification and handover documents, where applicable;
  • product, performance and workmanship warranties;
  • total price, VAT treatment, payment schedule and cancellation terms;
  • a written list of exclusions and provisional costs.

1. Scaffolding and roof access

Access can materially change the installation cost. A straightforward two-storey pitched roof is different from a tall townhouse, conservatory obstruction, narrow side access, fragile lower roof or property requiring pavement permits.

Ask:

  • Is full scaffolding included?
  • Does the price include permits, licences or special access?
  • What happens if the scaffolder changes the design after survey?
  • Is removal and any return visit included?

A quote that says “standard scaffolding included” should define standard.

2. Roof repairs and structural work

Installing solar does not repair an ageing roof. If tiles, felt, battens or the roof covering need replacement soon, doing that work after the array is installed can mean paying to remove and refit panels.

The current MCS solar PV installation standard requires installers to consider weather-tightness and structural integrity. It states that the roof structure should be checked by a suitably competent person and that unusual structures or signs of distress may require a structural engineer.

Ask whether the quote includes:

  • replacement of broken tiles discovered during installation;
  • structural calculations or an engineer’s report, if needed;
  • strengthening rafters or adding fixings;
  • making good around cable routes;
  • protecting an existing roof warranty.

3. Consumer unit, earthing and electrical upgrades

A survey may find that the existing consumer unit, earthing, cabling or protection is not suitable for the proposed system. The exact requirement is property-specific, so a responsible article cannot attach one universal price.

Ask the installer to identify what has already been inspected, what is included and what remains “subject to electrical survey”. If upgrades are optional rather than required, ask them to separate the recommendation from the installation minimum.

4. Grid connection and DNO work

The local distribution network operator (DNO) may need to be notified or asked for permission, depending on the system and connection route. Most domestic installers manage the paperwork, but the quote should say who is responsible and whether any non-standard network work is excluded.

Ask:

  • Will you complete the relevant notification or application?
  • Is the design conditional on DNO approval?
  • Could the inverter export be limited?
  • Who pays if network changes are required?

5. Optimisers, microinverters and shade-management equipment

Power electronics can be useful for complex roofs, multiple orientations, module-level monitoring or some shading situations. They are not free, and they are not a substitute for an honest shading assessment.

Compare like with like: one quote may include an optimiser on every panel while another uses a single string inverter. Ask why the chosen architecture suits your roof, how it changes annual generation, what extra components sit on the roof and what each warranty covers.

6. Bird protection and pest measures

Mesh or other deterrents are often optional. They may be included in one proposal and absent from another. Ask whether the product is compatible with the mounting system, whether installation affects product warranties, and whether future access for maintenance remains possible.

7. Monitoring, communications and subscriptions

Many inverters include an app or web portal, but the quote should clarify:

  • whether a Wi-Fi, Ethernet or mobile connection is required;
  • whether any data dongle or gateway is included;
  • whether monitoring has a recurring fee;
  • who owns the account and data;
  • what happens if the manufacturer’s service changes.

Monitoring can help identify faults, but it does not guarantee that an installer will proactively monitor your system.

8. Planning, listed-building and leasehold permissions

Many domestic roof-mounted installations can be permitted development, but conditions and exceptions apply. The Planning Portal advises checking limits and discussing uncertainty with the local planning authority. Listed buildings, some protected locations, flats, leasehold homes and properties with restrictive covenants may need additional permission.

Ask who is checking planning status, landlord or freeholder consent, and whether any application fee or design change is included.

9. MCS certificate, export setup and meter requirements

An MCS-certified installer should provide the consumer’s MCS certificate directly, normally within ten days of commissioning according to MCS guidance. Keep it with the handover pack.

The Smart Export Guarantee pays eligible generators for metered exports, but suppliers set their own eligibility rules and tariffs. Ask whether your quote includes:

  • commissioning documents and electrical certificates;
  • MCS registration and certificate;
  • export-meter configuration or smart-meter checks;
  • help with the SEG application;
  • proof of equipment eligibility required by the chosen supplier.

An installer cannot guarantee acceptance by every export supplier, but it should explain the paperwork it will provide.

10. Warranties and financial protection

“25-year warranty” is not one warranty. Separate:

  • panel product warranty;
  • panel performance warranty;
  • inverter warranty;
  • battery product or throughput warranty;
  • mounting-system warranty;
  • installer workmanship warranty;
  • insurance-backed protection if the installer stops trading.

Check who provides each warranty, what labour or access costs are excluded, whether registration is required and who pays scaffolding for a replacement. A long component warranty can still leave the homeowner paying diagnosis, labour or access.

11. Battery features that are easy to misunderstand

A battery quote should state usable capacity, continuous power, peak power, operating mode and warranty basis. “10 kWh battery” does not automatically mean 10 kWh is usable, nor does a battery automatically keep the whole house running during a power cut.

Ask specifically whether backup is included, which circuits are backed up, the maximum backup power, whether extra switchgear is required and whether solar can continue charging during an outage.

12. Finance interest, fees and early repayment

The cash price is not the financed price. Obtain:

  • cash price;
  • deposit;
  • interest rate and APR;
  • term;
  • monthly payment;
  • fees;
  • total amount repayable;
  • early-repayment terms.

Calculate payback using total finance cost, not the cash price. RECC reminds consumers that finance documentation has its own cancellation rights and should be reviewed separately.

13. Future maintenance and inverter replacement

Energy Saving Trust says solar panels require relatively little maintenance, but inverters typically need replacement after around 10 to 15 years and currently gives an indicative replacement cost of around £800. Cleaning needs depend on tilt and local conditions.

This is not necessarily an amount due on installation day, but it belongs in a lifetime-return model. Ask whether an extended inverter warranty is included and what it actually covers.

VAT: check the treatment, not just the total

Under current HMRC guidance, qualifying installations of solar panels and electrical battery storage in residential accommodation are zero-rated until 31 March 2027, with qualifying installations scheduled to return to 5% from 1 April 2027. Equipment supplied without installation and unrelated building work may be treated differently.

The quote should show the VAT rate applied and separate unrelated work where necessary. Do not accept “VAT saving” as a vague discount without a clear invoice treatment.

A copy-and-paste question for every installer

Send this before choosing a quote

“Please confirm in writing whether the quoted total is fixed and includes design, panels, inverter, mounting, scaffolding/access, installation, electrical work, DNO paperwork, commissioning, MCS certification, monitoring setup, warranties and VAT. Please also list every exclusion, provisional sum and circumstance that could increase the price after survey.”

Red flags in a solar quote

  • No system capacity in kWp or no exact equipment models.
  • A savings figure without annual generation, self-consumption and tariff assumptions.
  • “Free battery” without a separate cash-price comparison.
  • Pressure to sign before a technical survey or before receiving written terms.
  • A large deposit without clear protection.
  • Unclear warranty provider or no workmanship warranty details.
  • Key items marked “TBC” while the seller still presents the final price as fixed.

Compare the full scope, not the headline

Enter each installer’s equipment, capacity, price, warranties and forecast on the same screen. Differences become much easier to question.

Compare Solar Quotes

Frequently asked questions

What should be included in a solar panel quote?

A useful quote should identify the system size, equipment, design assumptions, estimated annual generation, shading, installation work, scaffolding or access, electrical work, certification, warranties, total price, payment schedule and any exclusions or provisional sums.

Is scaffolding normally included in a solar quote?

It may be included, priced separately or left subject to survey. Never assume. Ask the installer to state the access method and whether the quoted price can change if additional scaffolding is required.

Can roof repairs increase the cost of solar panels?

Yes. Solar panels should not be installed over a roof that needs near-term repair. MCS standards require the roof structure and weather-tightness to be considered, and unusual or questionable structures may require a structural engineer.

Are solar panels still zero-rated for VAT in 2026?

Qualifying installations of solar panels and electrical battery storage in residential accommodation are currently zero-rated until 31 March 2027 under HMRC guidance. Other work or equipment may be treated differently, so the installer should show the VAT treatment clearly.

Sources

Updated 6 August 2026. Requirements and costs vary by property, location and installer. This checklist is educational and does not replace a technical survey, contract review or professional advice.