Good afternoon,

we are a Housing Association purchasing a number of properties from a developer that are already built and have a roof mounted PV system with a battery energy storage system located in the loft space.  Whilst the installation does conform to the current regulations, it is not in line with the British Standards guidance as per below and the developer is stating the installations are fully compliant.

The PAS 63100:2024, issued by the BSI in March 2024, outlines that solar batteries should not be installed in voids, roof spaces, or lofts. However, it is crucial to understand that this PAS is not a regulation but rather a best practice guide. 

In accordance with official regulations, as long as certain considerations are met – such as having a fire alarm, smoke alarm, adequate lighting, and accessible entry points – solar batteries can indeed be installed in lofts. For comprehensive details, refer to Section 11, Table 11.1 of the IET Code of Practice, Electrical Energy Storage Systems, 2nd Edition.

It is important to note that regulations always take precedence over recommendations like the new PAS from the BSI.(https://nxtgenenergy.co.uk/blog/solar-industry-update-battery-installations-in-lofts)

Has anyone approached this from the fire safety perspective of where batteries are able to be installed in loft spaces quite close to roof trusses/combustible materials, and what approach (if any) have you taken to mitigate (other than those required such as lighting, access, smoke detection)?  We are currently consulting with our insurers but I thought it would be worth raising it as a topic for discussion, as our insurers seem to be offering advice relating to commercial installations and not from a residential pespective.

Thanks 

Building Regulation in the UK is never retrospective.

If the properties pre-date March 2024 you should not be using the PAS for judgement until such time as the property is considered for refurbishment.

What the developer, or rather the designer / architect, should be able to supply is their documented consideration of risk associated with the installation as executed.

Interestingly the only mention of batteries in Approved Document B "Fire Safety" is in reference to auxilliary power supply for detectors.

There is nothing in Approved Document P "Electrical Safety"

Systems are mentioned in Approved Document L "Conservation of Heat & Power" but nothing about the fire safety of an installations save for "in accordance with manufacturers instructions"