Solar photovoltaic (PV) arrays are becoming widely accepted as a means of partly providing a sustainable solution across the construction industry. This is particularly evident on the large areas of open roof space on non-domestic, industrial, commercial and warehouse buildings for both new build and retrofit (RMI) applications.

Buildings within these categories range from small starter units for SME businesses through to large distribution warehouses exceeding in a footprint area of 10,000 square metres. This represents an annual installed roof area of metal-based systems approaching circa 10 million square metres.

Design is a critical element of any sustainable PV solution and installation and should address both dead and imposed loading arrangement, installation procedures, lifetime maintenance and safety considerations relating to electrical and fire isolation and management. A further critical consideration is the guarantee and warranty requirements for associated products, components and materials which may form part of the PV system and the new or upgraded roof assembly. The adjacent links provide a source of information on these topics.

PD CEN/TR 16999:2019 Solar energy systems for roofs. Requirements for structural connections to solar panels. This document provides guidance on the principles and requirements of structural design for the safety and serviceability of the structural connection between solar energy panels (thermal or photovoltaic) and the structure.

It must be noted that the actual method of installation and attachment of the PV panel to the roof structure is project specific and in every case the installation should follow the detailed guidance provided by the manufacturer or supplier of the individual components and the manufacturer or supplier of the roof covering and substructure.

This document does not include requirements for:

• Weather tightness of the roof, solar panels and connections;
• Electrical, thermal or mechanical characteristics of the solar panels;
• Precautions against fire of the installation.

The document is available for purchase from BSI (see the link opposite).

Member companies within the MCRMA can offer guidance at the structural design phase; the suitability and supply of component parts and the interaction between component parts, the actual installation process and any phased inspection stages.