Geoff Wilkinson explains BRE’s study of lifts as an alternative means of fire escape
‘In the event of fire do not use the lifts’ is a sign we have all seen in UK buildings and is accepted wisdom on fire safety training courses. But that could be about to change.
The fire at Grenfell Tower has shown that the provision of compartmentation and a ‘stay put’ policy cannot be relied upon and increasingly we are hearing calls for a plan B in case of fire. This throws the concept of safe refuge into the spotlight, especially with respect to occupants with limited mobility or other disabilities.
Compared with the practical difficulties of movement by evacuation chairs, lifts undoubtedly provide for significant benefits in terms of ‘manpower’ required and time taken to complete descent to exit level.
Many high-rise buildings, such as the Shard, already have a fire strategy that uses the building’s lifts
In a survey carried out by the Building Research Establishment (BRE) in 2015, respondents overwhelmingly felt there was inadequate guidance on the provision of means of escape for disabled people.
As a result, the BRE looked at alternative options to address the issue, including the provision of lifts for evacuation in the event of a fire.
This is not an entirely new concept; many high-rise buildings (such as the Shard) already have a fire strategy that uses the building’s lifts. However, the cost of evacuation lift provision in buildings generally would be prohibitively costly, with a full fire-fighting evacuation lift typically costing in excess of £250,000.
The BRE study therefore looked at a range of options to see how lifts designed to a lesser standard could be used and considered four options: a full fire-fighting lift to BS 5588 Part 5; a full evacuation lift to BS 5588 Part 8, a ‘lift of beneficial use’*; and a standard lift with enhanced protection from fire-protected lobbies.
The reduced costs of these alternatives make it possible to consider a wider spread of potential applications. According to the study, an evacuation lift, for example, reduces the cost to between £138,000 and £250,000; a lift plus fire-protected lobbies was estimated to cost £90,000; while a beneficial use lift reduced the cost further to about £76,000.
Following BRE’s study, it is expected that future regulations will require (or at least promote) the use of lifts in the event of fire, either as a primary or secondary evacuation method. In the meantime, architects and building owners might wish to consider their wider liabilities under the Equalities Act 2010 and look to implement escape lifts within their current projects, especially in single-stair blocks of flats. In the Regs, the current guidance on the use of lifts for evacuation (with appropriate associated provision) can be found in Approved Document B (Para. 5.39) and BS 9999 (Para. 46.9).
BS 9999 makes the following recommendations for consideration (I paraphrase here):
- A lift remote from a fire may be used in its initial stages
- The fire alarm interface with lift functions should support the management strategy
- Controlled operation of the lift should be possible
- The power supply to the lift must be likely to remain useable throughout the time required for evacuation
- The lift enclosure and associated escape routes should remain free from the effects of fire during an evacuation
- A suitable communications system should be available to support the evacuation
- There should be an alternative escape route available if the use of the lift is not viable.
On any current project where fire evacuation is relevant this is a topic which will need to be discussed at some length with both Building Control and the fire officer, but the recommendations set out an alternative strategy that may well become part of the Regs in the near future.
Geoff Wilkinson is an approved inspector and managing director of Wilkinson Construction Consultants www.thebuildinginspector.org