Is your roof suitable for solar panels?

Roof condition comes first

Solar panels can last for decades, so the roof should be in suitable condition before the system is fitted. If the roof needs repair, strengthening or major works soon, solve that first.

• Ask the installer how they assess rafters, roof covering and mounting points.
• Confirm whether any extra timber support or access work is included.
• Avoid vague answers about leaks: the mounting method should protect roof weatherproofing.

Orientation and shading

A south-facing roof is usually strongest for total annual output, but east and west roofs can still be useful, especially if the household uses power in the morning or evening. Shading can matter more than compass direction.

Sizing the array

System size is normally expressed in kWp. A larger array may generate more, but bigger is not always better if most excess is exported at a low rate or if the roof layout is compromised.

• Match the design to annual kWh use and daytime demand.
• Check whether a battery, diverter or EV charging changes the recommended size.
• Ask for the expected annual generation and self-consumption percentage.
• Make sure the SEAI grant calculation is based on the eligible kWp band, not vague marketing copy.

Planning permission

Most ordinary domestic rooftop solar installations can proceed without planning permission, subject to conditions. Protected structures, conservation areas and unusual installations should be checked with the local authority before work starts.