The installer comparison framework
Start with minimum standards, then compare the quality of the proposal. A professional installer should explain why a system size suits your usage, how shading has been considered, what equipment is specified and what happens after installation.
If the answer to every concern is a discount that expires tonight, you have learned something useful.
| Criterion | What good looks like | Warning sign |
|---|---|---|
| Certification | MCS route explained clearly | Vague paperwork promises |
| Design | Roof, shading and usage considered | Same system offered to every home |
| Quote | Equipment and labour separated | One bundled number |
| Warranty | Product and workmanship terms clear | Warranty used as a slogan |
| Aftercare | Monitoring and fault process explained | No clear support route |
Questions worth asking before you choose
Ask who carries out the survey, who installs the system, whether subcontractors are used and who owns the warranty relationship. Subcontracting is not automatically bad, but silence about it is unhelpful.
Ask for an annual generation estimate and the basis for it. If a quote assumes very high self-consumption, ask how that was calculated from your actual usage pattern.
Common questions
How many solar quotes should I get?
Three quotes is a useful target for most homeowners. It gives enough contrast to spot pricing and design differences without turning the project into a paperwork hobby.