The ad-hoc development of buildings on campus-style sites can pose particular challenges for fire safety managers. David Stow guides us though the options to consider, from the design of buildings to day-to-day management.
The management of fire safety in university buildings has to be considered at the earliest possible stage in the design, as it can have a significant impact on how the finished building will look and function. Aspects that in the past were only considered towards the end of a project are now driving building functionality and architectural concepts. This has led to the people who will eventually manage, occupy and work in the building being consulted early in the design, to ensure that everyone’s needs have been considered.
With so many parties having an input, however, it is necessary to find a balance between providing the highest level of fire safety possible while meeting the constraints of the project. It is not just initial capital outlay that has to be considered, as a number of other areas are potentially more critical to the university, including:
– The ongoing maintenance cost of active systems
– The resilience of the building to withstand the effects of fire and to quickly get back into operation if a fire does occur
– The level of responsibility placed on the building management team
– The integration of systems between different buildings on site.
In order to meet the above criteria, the design team is often asked to look beyond the minimum life safety requirements of the Building Regulations, with the following areas being considered:
– Automatic fire suppression
– An increased level of compartmentation, particularly to stop the spread of fire and smoke between levels
– A high level of detection and alarm
– The provision of evacuation lifts for disabled occupants.
University buildings can pose a significant challenge to fire safety designers as they often contain open, interconnected spaces, with atria and large double-height compartments designed to bring light into a building and to allow the use of natural ventilation. It is therefore often a complex issue to provide adequate fire safety design, while meeting the architectural intent of the building and keeping the project on budget.
While there are clearly many aspects to be considered, two of the most pressing issues in managing fire safety at university buildings are assessed in further detail here.
Inclusive design
Universities typically have an on-site building management team, which is responsible for various aspects of fire safety such as monitoring alarms, managing evacuations and assisting disabled users out of the building. There can be confusion as to how far their responsibilities stretch and staff are often reluctant to take on too much responsibility without adequate training. This can be exacerbated by a high turnover of staff in building management roles, and hence the need for the university to monitor and pay for ongoing training.
A key area is in managing evacuations. With limited funds available, universities are now looking for the role of the building management staff in an evacuation to be ‘designed out’ as much as possible. An example of this is assisting disabled users out of a building during an evacuation. It is commonly assumed that this is the responsibility of the fire brigade, but its role is to fight the fire and rescue any occupants who may have become trapped or incapacitated in the building. It is therefore the building management’s responsibility to assist disabled users out of the building; hence an evacuation strategy has to be developed that clearly spells out what action building management should take in such circumstances. This can be developed with reference to the access statement, so that it is clear to the management staff how disabled users can access a building, and how they can escape in the event of a fire. The access statement could also include the use of pagers or a registration scheme for disabled occupants, so that staff can keep in better contact with them in the event of a fire.
Where stair evacuation is considered, staff would have to assist disabled users down the stairs and to a place of safety outside the building. However, carrying people down a number of flights of stairs, even if there is more than one person doing the carrying, can have significant health and safety implications.
To aid this process, stair traversing devices are often installed to allow disabled users to sit in a specially designed chair and be wheeled down by staff. But people have to be trained to use these systems, which can be costly and time consuming, and also still places a large responsibility on the building’s staff.
The most obvious way to design out this problem is to use the lifts, so disabled people could evacuate with minimal assistance. Better still, the lifts would be designed to allow self-evacuation by disabled occupants, although this is not a commonly proposed solution at present.
For lifts to be used for evacuation, they need to be designed with the following:
– An alternative power supply should the main supply fail (not necessarily a standby generator)
– A protected lobby approach at each level where disabled users can take refuge
– A protected route to the exterior at ground floor level
– A two-way intercommunication device between the protected refuge and the building management team.
Further details are available in BS5588: Part 8 Code of practice for means of escape for disabled people.
A common problem is where the lifts are accessed directly off a central atrium, and so it may not be desirable to provide a protected lobby between the lift and the atrium because of the need to maintain easy access in and out of the lifts. Two possible solutions are:
– Create a protected lobby at each level and a protected route to the outside at the ground floor level, through the use of automatic drop-down fire and smoke curtains. This means that under normal use, the open feel of the atrium and lifts is maintained. But in the event of a fire, the curtains would automatically close creating a protected enclosure and a protected route to the outside at ground level. Disabled users would enter the protected lobby through fire doors which would also automatically close upon detection of a fire. However, all active systems require ongoing testing and maintenance, and the reliability of such systems may need to be demonstrated to the approving authorities.
– Provide dual-entry lifts, with one side opening directly onto the atrium and the other side opening away from the atrium. On the side opening away from the atrium there could be a protected lobby at each level and a protected exit route at ground floor level. This has the benefit that there are no active systems involved in creating the lobby, but it does typically mean a loss in usable floor space.
The key issue for any strategy that relies on management regimes is for each case to be considered on its merits, with input from all user groups at an early stage in the design process. That way, problems can be faced head on and hopefully designed out.
The holistic approach
Space on university campuses is often at a premium, with buildings being constructed in close proximity to others and with many shared internal and external escape routes and inter-connections. This can have an impact on the evacuation strategy and often there is a need for a site-wide strategy to be developed.
To minimise disruption to students, universities often want each building on campus to be designed as standalone, with only the building of fire origin being evacuated initially. As the buildings have to be designed to prevent external fire spread occurring, in theory it should be safe for people in other buildings to remain in place until they are told to leave by the building management team or the fire brigade. In practice, however, if you can hear the fire alarm sounding in a neighbouring building and can see the other occupants escaping, it might be unrealistic to expect people to remain in place until being told to leave.
This could be considered as similar to a phased evacuation strategy, whereby only the occupants initially at risk are evacuated. A phased evacuation could be controlled by a voice alarm system, so that occupants in areas remote from the fire can be made fully aware of the situation and what action to take (or not to take). Bear in mind, however, that universities often contain a large number of international students for whom English is not their first language.
Instead of treating each building separately, it may therefore be necessary to develop a site-wide fire strategy and consider what impact each building has on its neighbours. Aspects that may need to be considered include:
– Is it appropriate to evacuate each building separately or should more than one building be evacuated at a time?
– Is there a common escape route that is shared between buildings, and would this have adequate capacity if occupants of more than one building were escaping into it?
– Do occupants have to escape past another building? If so, and if there is a fire in the neighbouring building that blocks the escape route, are there alternative escape routes for the occupants who will be prevented from using it?
– Could occupants be forced to escape through another building? The common areas of university buildings are typically very congested during lecture changeover periods. So even if only those in a single building evacuate at any one time, the escape routes leading through other buildings could still become extremely congested.
– Is the detection and alarm system capable of being integrated with systems in neighbouring buildings, such that the neighbouring buildings can be warned that there is a fire and that they may need to evacuate?
– Are there any conflicts between the escape routes and the fire brigade access routes?
– Is the building management team capable of coping with evacuation of more than one building?
A site-wide fire strategy would address all of these issues and would ensure that all fire and evacuation scenarios had been considered in turn, and an appropriate response planned. This might include a cause and effect matrix indicating, for each fire scenario, which occupants evacuate and which remain in place. It would also detail the response of the building management staff and any special responsibilities that they should be aware of. This could also encompass an extreme events study, because public buildings with large numbers of occupants are increasingly being designed to protect against an emergency scenario that could be unrelated to fire, but which may still require the simultaneous evacuation of a large number of people.
The university should already have a fire safety management plan which details the fire safety strategy for each building. But as new buildings get added to the campus and existing buildings get altered, the integration between buildings can get lost and fire strategies can become outdated.
It is therefore important to consider fire safety for university buildings by considering the bigger picture and what is happening on the rest of the site. What may seem like a straightforward design of a standalone building could actually be affecting the fire safety design of other nearby buildings.
David Stow is senior fire engineer at Arup Fire.
University of Brighton – New building on the Falmer Campus
The building, being designed by Hopkins Architects, contains a large central atrium connecting a number of levels, and has the main circulation elements – stair and lifts – accessed directly off the atrium. The lifts are designed for evacuation but protected refuges are also provided in the two external escape stairs. This ensures that disabled users have a choice of escape routes. Stair traversing devices are provided to enable the building management team to assist disabled users down the stairs and out of the building. This redundancy in the design is in line with the proactive strategy the university has adopted towards disabled users.
University of Sheffield – Jessop West Development
Architects Sauerbruch Hutton, in conjunction with RMJM, are designing a new building on the Jessop West site at the University of Sheffield. The university’s in-house fire safety advisor and building management team were consulted at an early stage of the design to ensure that the fire strategy would meet with their operational needs. As a result, two lifts accessed off a central hub space are being designed for evacuation. The building is designed so that in the event of a fire, the route into the central hub space would only be blocked at a single level. In this scenario, the building management team would be able to assist disabled users down one level using the stairs and then safely transfer to the evacuation lifts to escape to the ground floor. This increases the level of comfort for disabled users and makes full use of the evacuation lifts.
Kingston University – The Quad Building
Arup Fire is assisting John McAslan & Partners in the fire safety design of the new Quad Building at Kingston University. The tight site means that there is a number of constraints that have to be considered, including escaping through neighbouring buildings, integrating the detection and alarm system between buildings and maintaining adequate fire brigade access to the site. A site-wide fire strategy is being developed to address these issues, and to ensure that the escape routes and building management team can cope with the possibility of multiple buildings evacuating at the same time.
