Solar panels Home services checklist: what to do before you apply/buy

Your GB-ready solar buying checklist

Understanding solar is not just about wattage - it is about making a safe, compliant, and cost-effective decision for your home.

A well-prepared homeowner saves time, avoids rework, and secures better long-term returns.

Why this guide matters now

With rules easing in 2023 and new-build standards landing from 2025, more UK homes can benefit from rooftop solar. This checklist gives you a clear path to assess your roof, budget realistically, and choose certified installers who meet UK regulations.

Who should use this

• Homeowners in England, Scotland, or Wales considering rooftop solar within 12 months
• Owners of older or unusual roof types seeking clarity on structural needs
• Households aiming to cut bills, boost energy independence, or add battery storage
• Buyers who want a compliant, MCS-certified installation eligible for incentives

Key terms explained clearly

• kW / kWh: kW is system power capacity. kWh is energy produced or used over time. A typical UK home consumes 2,700 to 3,500 kWh yearly.
• 4 kW system: A common UK size needing around 20 m² of unobstructed roof space. Good for many 2-3 bedroom homes.
• Orientation and pitch: South-facing with roughly 30° pitch yields the best annual output in GB. East-west can still work with reduced yield.
• MCS certification: UK quality benchmark. MCS installers and products protect standards, compliance, and access to incentives.
• Inverter: Converts DC from panels to AC for your home. Usually indoors, near the consumer unit.
• Battery storage: Stores excess energy for evening use or outages, improving self-consumption and savings.
• G99 notification/approval: Grid connection process your installer handles to keep the system compliant and safe.
• Permitted Development: Most roof-mounted domestic systems in GB do not need planning permission if they meet limits and are not on listed buildings or in sensitive areas.

Choosing your setup

Common system choices

Panel types and roof fit

Keep at least 30 cm clearance from roof edges to meet MCS safety guidance.

What it costs, what you gain, and the risks

• Upfront costs: Many UK 4 kW roof systems range roughly £5,000-£7,500. Adding a 5-10 kWh battery can add £3,000-£6,000 depending on brand and integration.
• Bill savings: A well-sited 4 kW system can materially cut bills, especially with daytime use or battery storage. Savings vary by tariff, usage, and shading.
• Payback: Typical payback for solar-only might be 7-12 years, shorter with high daytime usage. Batteries often extend payback but increase self-consumption and resilience.
• Maintenance: Minimal. Occasional cleaning, inverter replacement typically once in 10-15 years.
• Risks: Poor roof suitability, shading, or non-compliant work can reduce output and value. Always use MCS-certified installers and obtain product warranties.

The cheapest quote is not the best value if it compromises output, compliance, or warranty support.

Are you eligible

• Property type: Most houses and many bungalows are suitable. Flats or leaseholds may need freeholder consent.
• Roof criteria: Ideally south-facing, 30° pitch, around 20 m² clear area for 4 kW. East or west can still work. Avoid shading from chimneys, trees, or neighbouring buildings.
• Structural integrity: Roof must support roughly 20 kg per m² from frames and panels. Older or complex roofs may need a structural survey and reinforcement.
• Permissions: Usually not required under Permitted Development if panels are roof-mounted and do not protrude excessively. Listed buildings and conservation areas often need explicit consent - check with your council.
• Compliance: Installation must meet UK building regulations and electrical standards. Choose MCS-certified installers and products for quality and incentive eligibility.
• Incentives: Check Boiler Upgrade Scheme and regional grants. Scotland’s Warmer Homes Scotland may fund improvements based on assessment.

What happens - start to finish

1. Initial site survey - roof, shading, electrics assessed
2. System design - size, layout, components, output forecast
3. Quote and contract - products, warranties, timelines agreed
4. Structural checks - reinforcements if required
5. Mounting fitted - rails or ballasted frames installed
6. Panels and inverter - safe placement and wiring
7. Grid paperwork - G99 and notification completed
8. Testing, handover - certificates, monitoring app, user briefing

Upsides and trade offs

• Pros: Lower bills, reduced carbon, potential home value uplift, battery resilience, minimal day-to-day maintenance.
• Cons: Upfront cost, roof work disruption for 2-3 days, inverter replacement in the long run, output depends on orientation and shading.
• Considerations: Panel placement must avoid shading and meet 30 cm edge clearance. Battery size should match evening usage. Ensure access to roof for future maintenance.

Do this before signing anything

• Get three MCS installer quotes with a yield forecast and product datasheets.
• Ask for roof loading calculations and, if needed, a structural survey.
• Confirm planning status, especially for listed buildings or conservation areas.
• Check warranties: panels 20-25 years, inverter 5-12 years, workmanship 2+ years.
• Verify G99 process, building regulations sign-off, and handover documents.

If solar is not a fit yet

• Improve efficiency first: LED lighting, draught-proofing, insulation upgrades.
• Consider smaller array or phased approach - add battery later.
• Explore community energy schemes or green tariffs while planning roof works.
• Revisit after roof repairs, tree trimming, or extension plans are complete.

FAQs

• Do I need planning permission in the UK? Usually no for roof-mounted systems under Permitted Development. Check with your council if your property is listed or in a conservation area.
• How long does installation take? Most homes complete in 2-3 days, excluding any structural works and grid notifications handled by your installer.
• Can my roof take the weight? Many roofs can support around 20 kg per m² from panels and rails, but older or unusual roofs may require reinforcement after a survey.
• Is a battery worth it? If you use most energy in the evening, a 5-10 kWh battery can lift self-consumption and savings, and provide backup during outages.
• What size system should I choose? Match to your usage and roof. A 3-5 kW system suits many homes; shading and orientation affect yield.
• Who should install the system? Always select MCS-certified installers so your system is compliant and eligible for incentives.
• Will panels work on flat roofs? Yes with ballasted mounts. Structural checks and wind loading calculations are essential.

Ready to move forward

• Shortlist MCS-certified installers and request like-for-like quotes.
• Prepare your last 12 months of bills and photos of your roof and consumer unit.
• Ask for a projection including seasonal output, battery benefits, and payback. Choose the proposal that balances cost, yield, and compliance.

Clarity first, contract second - it is the Switcha way.

Important information

This guide is general information for GB homeowners. It is not advice. Always confirm planning and building regulation requirements with your local authority and use certified professionals. Performance and savings vary by home, usage, and tariff.