01
Roof geometry
Usable area, orientation and inclination affect the layout and estimated yield. East-west roofs can still be useful, particularly when their output timing matches consumption.
02
Condition and structure
The roof needs to remain serviceable for the expected life of the installation. Ask how the installer assesses structure, coverings, fixings, waterproofing and access.
03
Shading and constraints
Trees, chimneys, neighbouring buildings, dormers and roof furniture can reduce output. Planning, listed-building, leasehold or freeholder constraints may need separate checks.