Commercial change of use to residential.

Hunter Seymour explores the many fire safety hazards and challenges involved in repurposing commercial premises for residential housing – an activity that has become more commonplace following the COVID-19 pandemic.

The UK government’s introduction of fast-track ‘Mercantile-to-Abode’ (MA) PDR conversions (Commercial-to-Residential Permitted Development Rights), announced this year, raises demanding questions for risk management as the new rules mean that Local Planning Authorities (LPAs) can give provisional approval for developments that bypass normal planning rules.

Major repurposing of commercial buildings will certainly prove challenging for those ‘responsible persons’ charged with the fire safety of premises formerly designed for open-plan office use. The changes will undoubtedly require a new mind-set for those affected.

The impact of the COVID-19 pandemic on how real estate is utilised and occupied is predicted to be critical factor in the UK’s economic recovery, further compounded by a chronic housing shortage. The post-Covid future of working from home (WFH) and the decline of high street retail, driven by the phenomenal growth of online shopping, are also bound to be an added influence on the trend towards commercial to residential conversions.

It is timely, then, to attempt to identify the emerging risks that could arise from the current trend towards ‘Adaptive Reuse’.

The challenges of open-plan conversion

To consider the question of large open-volume spaces – such as the industrial buildings so sought-after for fashionable ‘loft living’ – a practical specimen case is needed. Here, therefore (see diagrams), the challenging issues prompted by PDR commercial conversions are illustrated by a three-storey office block with open-plan floors (dia. 1) each floor with area of 2500sq. m (not including plant for services) surrounding an inner courtyard. There are four helical staircases (one at each corner of the site).

Large open plan offices are of greater height than residential and in this specimen case, the floor-to-ceiling height is 3.2m with pre-cast floor units spanning 14m to achieve unobstructed space. So, you might think, the perfect canvas – virtually blank – for residential conversion.

However, try to imagine resolving the complexities of its adaptation for domestic use: Equitable access to lifts (there are two lift shafts at the north west corner); complete reconfiguring of plumbing, ducts and risers for ventilation, heating and utilities; adjusted load-bearing criteria; repurposing washrooms and storage… not forgetting the immense challenges for compartmentation. And, critically, solving the problem of appropriate fire stairs and means of escape for the occupants of 40 apartments on each of three floors.   Read more….

The fire safety hazards of ‘quick-fix’ repurposing of commercial buildings for residential housing