Guidance

Combines extensive green roof principles with PV installation requirements. Requires careful integrated design.

Structural Assessment: Load includes green roof saturated weight PLUS PV panels, mounting system, ballast (if used), wind uplift loads. Structural engineer assessment is essential.

Green Roof Build-up: Follow extensive green roof guidance (waterproofing, root barrier, drainage, filter, substrate - min depth often dictated by ballast/vegetation needs for PV system).

PV Mounting System: Various options - ballasted (weight holds system down, requires sufficient substrate depth/load capacity), fixed (penetrates green roof layers, requires careful waterproofing detail). Ensure system allows for vegetation growth, maintenance access, and drainage beneath panels.

Vegetation: Select low-growing, drought-tolerant extensive green roof species (sedum, some wildflowers) that won't shade panels significantly. Vegetation under panels needs shade tolerance.

Layout & Shading: Position panels to minimise shading from vegetation, parapets, or adjacent structures. Maintain access paths around panels.

Electrical Installation: Requires qualified electrician following all relevant standards (MCS, BS 7671). Cable routing needs careful integration with green roof layers, avoiding damage to membranes.

Maintenance: Combines green roof maintenance (weeding, outlet checks) with PV maintenance (panel cleaning, electrical checks). Ensure safe access procedures.