Why we publish a checklist instead of testimonials
This site is an independent specialist guide to office solar, operated by SEO Dons Ltd — we are not the installing contractor, so publishing "our" customer reviews would be dishonest. What we can do is show you how to interrogate the review base of any installer who quotes for your building. On a £100k-£500k office install, an hour of due diligence is the cheapest risk reduction available.
MCS registration — the non-negotiable
Search the installer on the MCS register (mcscertified.com) before anything else. MCS certification is mandatory for Smart Export Guarantee eligibility and most grant routes. Check the certification covers commercial-scale work, not just domestic, and that it is current.
Companies House — age and financial health
A 10-year workmanship warranty is only as good as the company behind it. Check incorporation date, filed accounts, and any recent change of name or directors. A two-year-old company claiming "15 years of experience" is a red flag worth asking about directly.
Google reviews on the real trading entity
Search the exact registered company name, not just the brand. Read the 3-star reviews first — they tend to be the most informative. Check whether the installer responds to criticism, and whether reviews mention commercial projects or only domestic work.
Named, phone-able commercial references
For a six-figure office install, ask for two or three named commercial references with a similar building type and system size — and actually call them. Ask what went wrong (something always does) and how the installer handled it.
Insurance-backed warranty details in writing
Ask who underwrites the workmanship warranty if the installer ceases trading, and get the policy detail in writing. An insurance-backed warranty (IWA) through a rated insurer is the standard answer; vagueness here is a signal.
Site-visit evidence, not brochure claims
A credible commercial installer will model from your half-hourly meter data and survey the roof before quoting a fixed price. A quote produced without either is a guess — and reviews that praise "fast quotes" without mentioning survey quality can mislead.
Red flags in solar installer reviews and trust claims
- A perfect 5.0 average across a suspiciously round number of reviews
- Testimonials attributed only to job titles ("Operations Director, Midlands") with no verifiable company
- Install counts and "years established" claims that do not match Companies House
- Review schema markup on the website without visible, checkable reviews behind it
- Pressure to sign before a structural survey or DNO (G99) application
- No named commercial references offered, or references that cannot be called
None of these alone proves an installer is bad — but each one deserves a direct question, and the quality of the answer usually tells you what you need to know. Pair this checklist with our office solar cost guide so you can judge whether a quote is priced honestly, and the delivery process guide so you know what a well-run project should look like week by week.