Annex 2.B Additional guidance for hospitals
The recommendations contained in this annex are in addition to the guidance contained in Standards 2.1 to 2.15 and are unique to hospitals.
A hospital is a building used for the treatment of persons suffering from an illness or mental or physical disability or handicap. Whilst all residential buildings pose special problems because the occupants may be asleep when a fire starts, in hospitals the problems are greater as the mobility, awareness and understanding of the occupants may also be impaired. It may not be safe to evacuate them to the outside and in some cases it may even be harmful to move them within the building.
Horizontal evacuation - the staffing levels in hospitals tend to be higher than residential care buildings therefore the fire safety strategy is normally based on the progressive horizontal evacuation of the patients. The object is to move the patients into adjoining compartments or sub-compartments within a short distance where further evacuation can be made if necessary depending on the severity of the risk.
Fire safety in hospitals is also dependent upon the way a building is furnished, staffed and managed. Designers of hospitals may need to make reference to the relevant documents which comprise ‘NHS Scotland Firecode’.
2.B.1 Compartmentation
Compartment
Every compartment in a hospital should be limited to a maximum area of 1500m2. In addition, every upper storey and every basement storey should form a separate compartment.
To assist in the safe horizontal evacuation of the occupants in a hospital, every compartment should be divided into at least 2 sub-compartments by a sub-compartment wall with short fire resistance duration, so that no sub-compartment is more than 750m2. By providing a series of barriers, it is intended that patients or residents will be able to remain in the building and avoid the need for complete evacuation.
Minimum storey areas
Every storey at a height of more than 7.5m containing departments to which patients have access, should either:
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comprise at least 4 compartments, each of which should have an area of at least 500m2, or
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have a hospital street (see clause 2.B.3) and at least 3 other compartments.
In a hospital, every storey at a height of more than 18m containing departments to which patients have access, should either:
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comprise at least 4 compartments, each of which should have an area of at least 500m2, or
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have a hospital street (see 2.B.3) and at least 3 other compartments each of which should have an area of at least 500m2.
Fire hazard departments
A compartment wall with a medium fire resistance duration should be provided between:
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different hospital departments, and
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between a hospital department and a protected zone.
However short fire resistance duration is sufficient in a single-storey hospital.
The departments in list A below should:
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never be directly below, nor directly adjoin, the operating theatres, intensive therapy units or special care baby units, and
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be provided with a fire suppression system (as in clause 2.1.2) where they are directly below, or directly adjoin, any other hospital department to which patients have access.
LIST A
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boiler house
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central stores
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commercial enterprises
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flammable stores
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laundry
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main electrical switchgear
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main kitchens
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refuse collection and incineration
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works department.
A hospital department in list B below should be provided with an automatic fire suppression system (as in clause 2.1.2) where they are directly below, or directly adjoin, operating theatres, intensive therapy units, or special care baby units.
LIST B
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central staff change
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central sterile supplies
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hospital sterilising and disinfecting unit
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health records
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pathology
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manufacturing pharmacy.
Intensive therapy units
Every intensive therapy unit should be divided into at least 2 sub-compartments by sub-compartment wall with short fire resistance duration.
Every entrance to an intensive therapy unit should be either:
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from a hospital street (see clause 2.B.3), or
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through a lobby, enclosed with the same fire resistance duration as that recommended for a sub-compartment.
Fire hazard rooms
In order to contain a fire in its early stages, the following rooms are considered to be hazardous and should be enclosed by walls providing a short fire resistance duration (see annex 2.D).
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chemical stores
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cleaners’ rooms
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clothes storage
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day rooms with a floor area greater than 20m2
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smoking rooms
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disposal rooms
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laboratories
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lift motor rooms
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linen stores
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bedrooms where they are used by:
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elderly people, or
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those suffering with mental illness, or
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people with learning difficulties
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laundry rooms
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staff changing and locker rooms
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store rooms
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X-ray film and record stores
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all rooms within a main laundry in which delivery, sorting, processing packing and storing are carried out.
Combustibility
Compartment walls or compartment floors in a hospital should be constructed of non-combustible material. However a sub-compartment wall can be constructed with combustible material (i.e. material that is low, medium, high or very high risk) provided the wall has short fire resistance duration.
Junction with external walls
Where a compartment wall or sub-compartment wall meets an external wall, there should be a 1m wide strip of the external wall which has the same level of fire resistance duration as the compartment wall or sub-compartment wall, to prevent lateral fire spread.
Where a lower roof abuts an external wall, the roof should provide a medium fire resistance duration for a distance of at least 3m from the wall.
Cavity barriers need not be provided to divide a cavity above an operating theatre and its ancillary rooms.
Where cavity barriers are installed between a roof and a ceiling above an undivided space, the maximum limit of 20m should be applied (see clause 2.4.3).
The number of exits in a hospital should be calculated in accordance with clause 2.9.1 subject to the additional criteria below.
A minimum of 2 storey exits should be provided from a hospital. The number of storey exits increases in proportion to the number of patient beds. For example:
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any storey with more than 100 patient beds should have at least 3 storey exits
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any storey with more than 200 patient beds should have at least 4 storey exits
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any storey with more than 300 patient beds should have at least 5 storey exits.
Compartment exits - in a hospital where a storey is divided into 3 or more compartments, each compartment should have exits to:
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a compartment and a hospital street, or
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a compartment and an escape stair, or
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a compartment and a final exit.
Each sub-compartment should be provided with at least 2 exits by way of protected zones and unprotected zones to adjoining, but separate, compartments or sub-compartments.
Travel distance in a hospital should not exceed 15m in one direction of travel and 32m in more than one direction. Travel distance may be measured to a protected door in a compartment wall or a sub-compartment wall however the escape route should not pass through any of the fire hazard rooms listed in annex 2.B.1.
In addition, the maximum travel distance from any point within a compartment should be not more than 64m to:
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each of 2 adjoining compartment, or
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an adjoining compartment and an escape stair or a final exit, or
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an adjoining compartment and a final exit, or
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an escape stair and a final exit.
Occupants may need to be evacuated horizontally through a protected door into an adjoining compartment. In such cases, each compartment should be capable of holding the occupancy capacity of that compartment and the occupancy capacity of the largest adjoining compartment.
Hospital streets
A hospital street is a protected zone in a hospital provided to assist in facilitating circulation and horizontal evacuation, and to provide a fire-fighting bridgehead. A hospital street should have an unobstructed width of at least 3m. It should be divided into at least 3 sub-compartments and not contain a shop or other commercial enterprise.
At ground storey level, a hospital street should have at least 2 final exits. At upper storey level there should be access to at least 2 escape stairs accessed from separate sub-compartments, located such that:
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the distance between escape stairs is not more than 64m, and
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the distance of single direction of travel within the hospital street is not more than 15m, and
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the distance from a compartment exit to an escape stair is not more than 32m.
A door from a hospital street to an adjoining compartment should:
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be located so that an alternative independent means of escape from each compartment is available, and
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not be located in the same sub-compartment as a door to a protected zone containing a stairway or lift.
Every escape stair opening into the hospital street should be located so that the travel distance from an escape stair exit to a door leading directly to a place of safety is not more than 64m.
Destination of escape routes
An escape route from a hospital department to which patients have access should be to:
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a place of safety, or
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a protected zone, or
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an unprotected zone in another compartment or sub-compartment.
Bed-patients may be moved to another ward in a different compartment or sub-compartment.
Escape route width
The unobstructed width of every escape route intended for bed-patient evacuation should be at least 1500mm. Doors should be designed to accommodate bed-patient evacuation.
Mattress evacuation stair
In patient sleeping accommodation, an escape stair width should be not less than 1300mm and designed so as to facilitate mattress evacuation. The landing configuration should also follow the guidance in the table below in order to assist the evacuation of bed patients. The additional 200mm for the landing width allows for the return of the balustrade between stair flights. In a straight through stair, the landing width need only be the same as the effective width of the stair.
Table 2.17. Stair and landing configuration for mattress evacuation in mm
| Stair width | Minimum landing width | Minimum landing depth |
|---|---|---|
| 1300 | 2800 | 1850 |
| 1400 | 3000 | 1750 |
| 1500 | 3200 | 1550 |
| 1600 | 3400 | 1600 |
| 1700 | 3600 | 1700 |
| 1800 | 3800 | 1800 |
Locks
Hospitals can present difficulties when assessing the risks associated with security against the need to evacuate the building safely in the case of fire. Some parts of hospitals could have patients who might put themselves at risk. An example could be a patients ward on an upper floor providing accommodation for the elderly or mentally infirm, where there is concern about residents falling down stairs. In such cases, variation in the guidance to Standard 2.9 would be entirely appropriate where the risk of death or injury from falls is assessed against the hazard associated with fire. The security measures proposed should therefore take account of these hazards and extra emphasis may need to be placed on management control and/or any automated life safety systems to ensure the safe evacuation of the building.
Protected lobbies
Where an escape stair in a protected zone serves an upper storey containing a department to which patients have access, access to the protected zone should be by way of a protected lobby (as described in clause 2.9.23), or, in the case of a storey at a height of not more than 18m, by way of the hospital street.
Essential lighting circuits should be installed throughout a hospital and designed to provide not less than 30% of the normal lighting level. In an area where a 15 second response time would be considered hazardous (e.g. a stairway) emergency lighting should be provided by battery back-up giving a response time of not more than 0.5 seconds.
The distribution boards for essential and non-essential circuits may be in the same location but should be in separate cabinets.
An automatic fire detection and alarm system should be installed in every hospital to ensure that staff and patients are given the earliest possible warning of the outbreak of fire anywhere in the building. This will allow staff to initiate progressive horizontal evacuation procedures in the early stages of fire growth.
The automatic fire detection system should be designed and installed in accordance with the guidance in BS 5839: Part 1: 2002 Category L1 and in accordance with the recommendations below:
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detection need not be provided in the following locations:
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a lockable cupboard with a plan area not more than 1m2
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in a void and roof space which contain only mineral insulated wiring, or wiring laid on metal trays, or in metal conduits, or metal /plastic pipes used for water supply, drainage or ventilating ducting
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manual fire alarm call points manufactured to BS EN 54: Part 11: 2001 (Type A) should be located and installed in accordance with BS 5839: Part 1: 2002
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the fire alarm should be activated on the operation of manual call points, automatic detection or the operation of any automatic fire suppression system installed
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the building should be divided into detection zones not extending beyond a single sub-compartment
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the audibility level of the fire alarm sounders should follow the guidance in BS 5839: Part 1: 2002. However in a hospital department to which patients have access, the audibility need only be 55dB(A) or 5dB(A) above the level of background noise, whichever is greater
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a main fire alarm control panel is provided at:
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the main entrance, or a suitably located secondary entrance to the building, and
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repeater panels should be provided at all other fire service access points
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on the actuation of the fire alarm, a signal should be transmitted automatically to the fire service, either directly or by way of a remote centre, designed and operated in accordance with BS 5979: 2000.
In the case of a hospital designed to accommodate not more than 10 residents, the fire detection and alarm system may be installed in accordance with clause 2.11.7 for other residential buildings.
The additional guidance in this clause applies to a hospital with hospital streets. Otherwise, the recommendations in the guidance to Standard 2.14 should be followed.
Where a hospital with a hospital street has 2 or more escape stairs, facilities should be provided in accordance with the table below (other than where agreed with the verifier and relevant authority). If an automatic fire suppression system is installed in the building, no point on the storey should be more than 60m from the main outlet, measured along an unobstructed route for laying a fire hose. If the building throughout is not fitted with an automatic fire suppression system, no point on the storey should be more than 45m from the outlet.
Different fire-fighting facilities should not be provided throughout the varying storey heights of a building. Once the topmost storey height of a building has been established, the intention is that fire-fighting facilities recommended at that height should be applied throughout the escape stair. Similarly, where a building contains a basement, the recommendations become more demanding the greater the depth.
Table 2.18. Facilities on escape stairs in hospitals with hospital streets
| Height and depth of storey above or below fire and rescue service access level [1] | Facilities on escape stairs |
|---|---|
| Basements at a depth more than 10m | fire-fighting stair (see clause 2.14.3); fire-fighting lift (see clause 2.14.4); fire-fighting lobby (see clause 2.14.5); ventilation to stair and lobby (see clause 2.14.6); dry fire main (outlet located at every departmental entrance) (see clause 2.14.7). |
| Basements at a depth not more than 10m | fire-fighting stair (see clause 2.14.3); ventilation to stair (see clause 2.14.6); unvented fire-fighting lobby (see clause 2.14.5); dry fire main (outlet located at every departmental entrance). |
| Topmost storey height not more than 18m | fire-fighting stair (see clause 2.14.3); ventilation to stair (see clause 2.14.6); unvented fire-fighting lobby (see clause 2.14.5); dry fire main (outlet located at every departmental entrance). |
| Topmost storey height not more than 50m | fire-fighting stair (see clause 2.14.3); fire-fighting lift (see clause 2.14.4); fire-fighting lobby (see clause 2.14.5); ventilation to stair and lobby (see clause 2.14.6); dry fire main (outlet located at every departmental entrance) (see clause 2.14.7). |
| Topmost storey height not more than 60m | fire-fighting stair (see clause 2.14.3); fire-fighting lift (see clause 2.14.4); fire-fighting lobby (see clause 2.14.5); ventilation to stair and lobby (see clause 2.14.6); wet fire main (outlet located at every departmental entrance) (see clause 2.14.7). |
Additional information:
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The access level is the level at which the fire and rescue services enter the building to commence fire-fighting and rescue operations.
Horizontal dry fire mains - every single-storey hospital with a hospital street should be provided with a dry fire main. The outlet should be located in the hospital street at every hospital departmental entrance. However if an automatic fire suppression system is installed in the building, a dry fire main need not be provided where no point within the storey (not being a protected zone) is more than 60m measured along an unobstructed route for the fire hose, from the access point or points. If the building throughout is not fitted with an automatic fire suppression system, no point within the storey should be more than 45m from the access point or points.