Compare the complete installation, not just the price printed at the bottom of each quote. Different equipment, roof access arrangements and exclusions can make similar totals cover different work. Ask each installer to survey your home and explain their proposed design in writing. This guide gives you a working comparison sheet rather than another general cost breakdown.
For the broader overview, read our guide: Install Solar Panels Cost Breakdown for UK Homeowners.
Independent guide. We are not a lender or a government body. Always check current scheme rules with the official provider.
1. Set the same brief for every installer
Give each firm the same electricity bills, roof information and battery preference before asking for a quote. Explain any planned heat pump, roof repairs or changes to household electricity use. Ask the installer to separate your current requirements from optional future upgrades. Keep the original brief beside every quote so changes remain visible.
System size alone does not establish whether a proposal fits your home. Ask how the design responds to usable roof space, shading and your electricity use. Request the panel and inverter model names, rather than accepting a general description of premium equipment. If a firm changes your brief, ask for its reasons before comparing the total.
- Write down the work you want included, including any battery option.
- Request a home survey and an itemised written quote from each MCS-certified firm.
- Ask installers to identify assumptions, exclusions and optional equipment separately.
2. Complete your quote comparison sheet
Copy the details from each written proposal into the table below. Leave an entry marked not confirmed if the installer has not supplied an answer. Do not treat an empty box as included work or an unlimited warranty. Send the incomplete sheet back to the installer and request written clarification before deciding.
| Installer | MCS number | System size | Panel and inverter models | Battery included | Scaffolding included | Warranties | Total price | Payment terms |
|---|---|---|---|---|---|---|---|---|
| Quote A | To complete | To complete | To complete | To confirm | To confirm | To complete | To complete | To complete |
| Quote B | To complete | To complete | To complete | To confirm | To confirm | To complete | To complete | To complete |
| Quote C | To complete | To complete | To complete | To confirm | To confirm | To complete | To complete | To complete |
Read equipment warranties separately from the installer's workmanship protection. Ask who handles a fault, what evidence they require and which costs remain your responsibility. Compare payment stages against clearly described work rather than an unexplained demand for a deposit. If finance is offered, request the lender's name and the total cost of credit.
3. Resolve differences before choosing
Get three written quotes and use unanswered questions to guide your follow-up conversations. A cheaper proposal needs scrutiny if it excludes roof access, electrical work or equipment another firm includes. A more expensive proposal also needs an explanation of what the extra work achieves. Ask for a revised written quote whenever the agreed specification changes.
Check the MCS number against the company offering the installation, then review its consumer code membership. Use the FCA register when checking a proposed lender or finance provider. Do not let a short-lived offer replace these checks or rush your decision. Keep your completed table, written answers and final specification together for the installation handover.
Checklist
- My quotes follow the same written brief.
- I have checked every MCS number.
- I have confirmed equipment, scaffolding and battery inclusions.
- I understand warranty responsibilities and payment terms.
- I have written answers to every exclusion.
Frequently asked questions
Should I choose my lowest quote?
Compare the complete scope first. A lower total can exclude work or equipment included elsewhere, so ask installers to explain differences.
How do I compare different system sizes?
Ask each installer to explain its design against your roof and electricity use. Do not assume the largest system is the right fit.
What if my quote leaves out scaffolding?
Ask whether roof access is included and who arranges it. Request a revised written total rather than relying on a verbal answer.
Can I use this table for my financed installation?
Yes. Add the finance provider and total cost of credit to your notes, then compare those terms separately from installation quality.
So you can compare complete solar proposals and choose with the important differences recorded.
WHLS Editorial Team
Our editorial team writes independent, plain-English guides on home energy finance. We review guides when scheme rules change.
References
- Energy Saving Trust – Solar panels (opens in a new tab)
- Planning Portal – Solar equipment planning checks (opens in a new tab)
- GOV.UK – Register energy devices (opens in a new tab)
- Energy Saving Trust – Solar panel cleaning and maintenance (opens in a new tab)
- Electrical Safety First – Solar panels (opens in a new tab)
- MCS – Find an installer (opens in a new tab)
- Energy Saving Trust – Consumer protection (opens in a new tab)
