As the number of tall buildings rises in urban areas, the need for new thinking on evacuation strategy becomes ever more pertinent. John Robb explores the importance of emergency lighting in helping occupants escape to safety
IT HAS been estimated that by 2020 the UK will invest $228 billion in commercial property development: nearly a 15% increase from 2015, according to the HIS Building Construction Report. More commercial property means more inhabitants that need to be evacuated safely in the event of an emergency.
As a result of urbanisation and population growth, new buildings are taller than ever before in order to avoid expansion into the Green Belt. In London, there are currently 455 tall buildings in the pipeline, according to New London Architecture (NLA). This includes 108 in the planning system, 256 that have already been granted permission and 91 which are already under construction. Next year another 28 towers of at least 20 storeys will be completed and 40 more the year after that1.
Tall buildings bring about massive evacuation challenges. In the event of an emergency, safely evacuating a skyscraper with 49 floors and more than 5,000 occupants is an incredibly complex and difficult process. When a building is multiple storeys high, the stairs act as major constriction points causing congestion on the escape routes, and the risk of people stumbling on stairs is considerably higher than on a level escape route.
Another trend that impacts on the process of evacuation is that many of the newest commercial buildings are multifunctional, providing not only conventional offices space but leisure, retail, overnight accommodation and entertainment facilities too. Multifunctional buildings that include residential and commercial premises, as well as restaurants and shops, are far more vulnerable to fire and other hazards that could lead to a mass evacuation.
A key challenge in the evacuation of tall buildings is the need to account for the whereabouts of occupants on multiple floors. This issue is exacerbated by the growing popularity of flexible working, as the fight to retain highly skilled staff, boost productivity and engage employees has become fiercer. According to research carried out by CIPD (Chartered Institute of Personnel and Development), all large employers offer flexible working to some employees, as do 95% of medium sized organisations. This, combined with new UK legislation around employees’ rights to flexible working, means that 20 million more people can now work flexibly.
In many companies, the sign in/sign out system has become inadequate, and offices that offer an array of facilities, such as gyms and relaxation areas, make monitoring the whereabouts of employees even more difficult.
Another factor that impinges on evacuation planning, especially in large, multipurpose buildings, is the mixture of employees and visitors who may be present. While employees ought to know about emergency procedures and exit routes, visitors may not have familiarity and would require specific guidance to help them. This is one scenario where voice announcements, call points and dynamic exit signage can be crucial.
Another important demographic to consider is elderly and disabled occupants of tall buildings. There are more than 11 million people in the UK with a limiting long term illness, impairment or disability.
Emergency lighting has a vitally important role in helping guide building occupants to safety. In the event of a power failure caused by a fire or another emergency, people could be plunged into darkness. Without clear illumination, people within the building could be endangered by physical hazards or obstacles and are likely to panic, potentially inhibiting any attempt to evacuate the building swiftly and safely.
Consider, for example, a multi storey hotel or hospital building, where occupants may be unfamiliar with exit routes and need lighting to find their way to safety. The main requirements for emergency lighting are firstly that they switch into action automatically, and secondly that they provide sufficient levels of illumination to enable all occupants to evacuate safely.
The obligation to provide emergency lighting is set out under the Regulatory Reform (Fire Safety) Order 2005 [FSO], and the British Standard BS 5266-1:2011 gives designers clear guidelines on the technical requirements. Failure to comply with these stipulations not only puts lives at risk and raises the possibility of prosecution, but can also invalidate insurance policies.
However, the way in which emergency lighting is specified, installed and maintained in a particular building must be determined by the completion and regular revision of a formal risk assessment.
If you have five or more employees, you are required by law, under the FSO, to carry out a fire safety risk assessment and must keep a written record of the assessment. This legislation exists to ensure that the correct emergency lighting is installed to cover any identifiable risks and that it will correctly operate in the event of a failure of the mains lighting supply. BS 5266 is the code of practice for the emergency lighting of premises, which provides information on the correct emergency lighting for the safety of people.
Additionally, the BS 5266 code, along with the BS EN 1838 code, provides specifiers with information regarding areas that need emergency lighting such as: the minimum levels of illumination, duration, maximum brightness to prevent glare, and any points of emphasis which require particular consideration.
These are described as high risk areas, and can include evacuation refuges, call points, exit doors or locations where hazardous machinery or processes may be in operation, for example.
Other categories of emergency lighting include emergency escape lighting, escape route lighting, open area (or anti panic) lighting and standby lighting. It is also important to consider the illumination of exit signs. Again, there are guidelines on the positioning, colour characteristics and luminescence levels of these.
Given that emergency lighting will never be used on an everyday basis, it can be tempting to opt for cheaper luminaires. These are often supplied from distant sources and will pass through numerous intermediaries before installation. This can lead to confusion over the precise specifications and the claims made by manufacturers and sellers, which may not be independently verified. Buying cheaply may also turn out to be a false economy since lower quality components can shorten the lifespan of batteries and lamps; they may also have inferior optics, resulting in more fittings being required to meet the minimum emergency lighting levels.
As part of this process, it is important to consider energy efficiency implications of emergency lighting over the long term. Good quality products may have a higher output and better spacing performance, meaning that fewer units are needed to achieve the required level of illumination, which may not only reduce the outlay on products but also the installation cost, as well as long term energy costs.
LED based emergency luminaires, for example, use less power, which reduces running costs and maintenance requirements. LED based emergency luminaires have a working life often greater than 50,000 hours, which is up to 10 times longer than a conventional fluorescent lamp.
Buyers should be encouraged to look for products approved by third party certification schemes such as BSI Kitemarking and the Industry Committee for Emergency Lighting (ICEL) registration. The BSI governs the implementation of strict European standards on the design and manufacture of emergency luminaires under regulations including EN 60598-1 and EN 60598-2-22. Meanwhile, the manufacturers’ trade organisation ICEL provides a product auditing and approval process.
Alongside product selection, the positioning of emergency lighting is crucial. Key locations where emergency luminaires should be installed include escape routes, changes of direction, adjacent to any step or trip hazard, flights of stairs, close to firefighting equipment, and call points and first aid points.
The responsibilities concerning emergency lighting do not stop, however, at the point of installation. Minimum routine testing schedules are one of the requirements of the regulations and standards.
The requirement for routine testing of emergency lighting is set out by the FSO2, and detailed guidelines for how these tests should be conducted are defined by the standards BS EN 50172 and BS 5266-13. A short duration or function test must be carried out at least once a month, normally by a member of staff who should be adequately trained.
Additionally, at yearly intervals, a full duration test must be carried out and supervised by a competent person, whereby the system operates for its full duration (whether that is one hour or three hours). It is important to note that during full duration tests, the batteries supplying the emergency lighting system will be completely discharged, and must therefore be allowed time to recharge before becoming functional again.
In accordance with BS 5266-1, a number of steps should be taken whenever a fault is found. Firstly, either the supplier of the system or a competent engineer should be contacted to rectify the fault. Secondly, a risk assessment of the failure should be conducted to determine the level of risk and assess who might be affected. Until the system is rectified, it may be deemed necessary to warn occupants to be extra vigilant, to initiate safety patrols, to issue torches as a temporary measure or even limit the use of the affected area if it is considered to be a high risk situation.
The testing regime is undoubtedly a demanding process in terms of time and resources. Failure to comply could be due to poor awareness of the regulations, lack of resources to run a testing routine or failure to correctly assign responsibility internally. Regardless of the reason, this not only places building occupants, assets and business activity at risk, but also makes organisations vulnerable to prosecution, leading to heavy fines and sometimes imprisonment.
Manual testing schedules in tall buildings can require teams of on site or contracted engineers to check every emergency light on every floor. Each emergency luminaire must be activated and then deactivated to ensure that mains lighting is automatically restored. At some large sites with multiple buildings, for example, it is not unusual for a team of two engineers to spend up to a week each month testing emergency luminaires, completing paperwork to log the findings and rectifying any faults they identify.
Bearing in mind the costs and disruption associated with tests, it is perhaps surprising that there is not greater adoption of automatic testing technology, whereby the network of emergency luminaires is monitored electronically by an addressable system at designated monthly and annual intervals. Any faults that are detected can be flagged immediately on remote devices for remedial action. This can produce a faster response compared with manual testing routines, whereby a fault that occurs shortly after one monthly test will not become apparent until the next monthly test.
An additional advantage of automatic testing technology is that the entire test and test results can be logged on local devices and networked to a central PC. Some PC software allows for remote access and email notifications to be sent. This helps to maintain the records that are required for compliance purposes.By eliminating the risk of human error, technology provides an assurance that the test has been conducted fully and accurately, which is highly valuable from both safety and compliance perspectives
John Robb is commercial buildings segment manager for Eaton EMEA
1 London Evening Standard, 25 April 2017, http://www.standard.co.uk/lifestyle/design/how-new-skycrapers-including-the-1000ft-trellis-will-transform-londons-skyline-a3522986.html
2 Regulatory Reform (Fire Safety) Order 2005,
3 BS EN 50172, Emergency Escape Lighting Systems; and BS 5266-1: 1911, Code of Practice for the emergency lighting of premises other than cinemas and certain other specified premises used for entertainment. http://www.icel.co.uk/files/docs/icel-1006-emergency-lighting-design-guide-hyp-10-1-2013-pdf-1360669544.pdf
For further information visit www.eatonworksafe.com