Buying without getting burned

What to ask a solar installer

Short answer

Ask what assumptions the generation estimate uses, whether scaffolding and a consumer unit upgrade are included, who handles the DNO application, what the inverter warranty is separately from the panel warranty, and what happens if the survey finds the roof needs work.

Sources checked 2026-09-09
Older British homeowners reviewing a solar quotation together at their kitchen table
Compare the eligibility conditions and the complete installation scope before relying on a grant or quote. · Original UKSolars editorial image

Ask the same questions of every installer and require the important answers in the quotation.

The 12 questions

  1. What roof direction, pitch and shading did you use in the generation estimate?
  2. What is the total system capacity in kWp and the panel count?
  3. Which panel, inverter and mounting models are specified?
  4. Is scaffolding included?
  5. Is consumer-unit or other electrical work included?
  6. What happens if the roof survey finds repairs are needed?
  7. Who submits the network application or notification?
  8. Which installation and electrical certificates will I receive?
  9. What does each warranty cover, and who pays labour?
  10. How are my deposit and advance payments protected?
  11. Who handles faults after installation?
  12. What can change the price after I sign?

A verbal answer is not part of the contract

Ask for material promises, exclusions and changes in writing. Keep the signed quotation, design, terms, certificates and warranties together.

Use the answers to compare installers on scope and accountability, not sales confidence.

Sources

Checked 2026-09-09. Rates, rules and eligibility can change. Confirm current terms before signing a contract or applying for funding.

Work out the number before anyone quotes you

Every assumption editable, nothing sent anywhere, no email. It will not give you a quote, but it will tell you whether one is fair.

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