A significant update to siphonic drainage legislation has arrived with the publication of BS 8490:2025 in February this year – a change that is expected to have widespread implications for commercial property owners and facilities professionals across the UK.
Under the new British Standard, buildings with internal gutters must now feature both primary and secondary siphonic drainage systems to remain compliant – even if the existing primary system has the capacity to handle rainfall volumes. This update follows a sustained increase in precipitation, with rainfall levels now up to 60 per cent higher than historical norms.
In response, NSS – part of Premier Technical Services Group Ltd (PTSG) and a key player in the field of building access and maintenance – is delivering a specialist seminar to help property professionals navigate the new regulations. The event will form part of the group’s Continuing Professional Development (CPD) programme.
The seminar will be led by Billy Gordon, NSS Group’s Head of Siphonic Drainage. With over two decades of experience and a seat on the Siphonic Roof Drainage Association (SRDA), Mr Gordon will provide vital guidance on the implications of the new standard and the practical steps organisations must take to ensure ongoing compliance.
“This marks the most significant update to siphonic drainage standards in nearly 20 years,” said Mr Gordon. “It’s essential that anyone involved in managing or maintaining property is aware of their new responsibilities under BS 8490:2025.”
The seminar is aimed at professionals across the built environment, including surveyors, facilities and estate managers, and health and safety leaders.
