Seven Assumptions That Collapse When a Building Changes Use
Planning permission is not the finish line
Change-of-use projects have a habit of looking finished before they are safe. The plans are approved, the fit-out is complete and the new occupants are moving in. What often remains unresolved is the safety documentation that should have changed with the building. A change of use can alter how people escape, how much electrical load the building carries, where asbestos may be disturbed and how many people are likely to be inside at once. Planning permission may permit the new use, but it does not certify the building as safe for that use.
1. That planning permission is the same as safety approval
Planning permission and building regulations approval are separate processes. Planning deals with land use, appearance and local impact. Building regulations deal with construction standards, including fire safety, means of escape and accessibility. A change of use may require building regulations approval even where planning permission has been granted. The fire risk assessment also needs to be reviewed because the premises, the people and the risks have changed. A compliant-looking building can still be non-compliant if the paperwork stops at the planning decision.
2. That the existing fire risk assessment still applies
A fire risk assessment is not a generic document that follows the walls. It is based on the activities, occupancy and layout of the premises. An office has different ignition sources, working patterns and escape needs from a gym, a clinic or a studio. A gym may introduce heavy equipment, saunas, changing areas and higher occupancy at peak times. A clinic may introduce medical equipment, waiting areas and vulnerable visitors. A studio may introduce theatrical lighting, blackout conditions or public events. The old assessment may be technically valid as a document, but it is unlikely to be suitable and sufficient for the new use.
3. That means of escape will work unchanged
Escape routes are sized and arranged around the expected number and type of occupants. A change of use can invalidate those assumptions. A retail unit converted into a clinic may create a waiting area that obstructs a corridor. A warehouse converted into a studio may introduce locked doors, blackout drapes or temporary seating that narrows an exit. A gym may have changing rooms with reduced visibility or doors that are not immediately recognisable as emergency exits. Travel distances, exit widths, signage and emergency lighting all need to be checked against the new layout and occupancy.
4. That the electrical installation can cope
New uses bring new electrical demands. Gym equipment, medical devices, studio lighting, kitchen equipment and additional air conditioning can all increase load and alter the pattern of use. An Electrical Installation Condition Report may exist, but it may have been produced for the previous occupier and the previous load profile. Sockets may be added informally during fit-out. Cabling may be routed through areas that are now more hazardous. The electrical safety case should be reviewed alongside the change of use, not treated as a separate maintenance issue.
5. That asbestos only matters during refurbishment
Asbestos-containing materials are often disturbed during fit-out works, but the risk does not end when the contractor leaves. A change of use can put people into parts of the building that were previously inaccessible, or introduce activities that damage asbestos-containing materials over time. The asbestos register and survey should be checked before work begins and updated afterwards. Contractors need to know what is present and what to do if they find something unexpected. A building with no visible asbestos problem can still have a hidden management problem.
6. That occupancy numbers will stay broadly the same
Change of use often changes density. A warehouse may have few occupants; a studio may host public events. A retail unit may have staff and customers; a clinic may have patients, visitors and vulnerable groups. Occupancy affects means of escape, ventilation, sanitary provision and fire safety. It also affects licensing and building regulations requirements in ways that are not always obvious from the floor plan. The responsible person should calculate realistic maximum occupancy for the new use, not rely on the number of desks or tills that were there before.
7. That the lease or handover covers compliance
In a leased building, change-of-use projects often involve the landlord, the tenant and a fit-out contractor. Each may assume that someone else has updated the fire risk assessment, tested the alarms, reviewed the electrical installation or checked the asbestos register. The lease may allocate responsibility, but it rarely closes every operational gap. A handover pack should include current safety documentation, not just keys and warranties. If the documents are missing, the new occupier inherits the risk along with the premises.
How to spot a compliant-looking but non-compliant building
Start with the document trail. Check whether the fire risk assessment reflects the new use and the date it was reviewed. Ask for building regulations completion evidence where required. Review the latest electrical installation condition report and any asbestos survey or register. Compare the actual layout with the escape plan and look for blocked routes, locked exits and missing signage. Confirm that occupancy assumptions are realistic and that contractors have been given the relevant safety information. A building can look finished and still be waiting for the compliance work that should have happened before the doors opened.