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Over 4,000 fires occur in retail outlets every year and on average larger fires cause over £5m of damage annually. Following the outbreak of a small fire in a shop, it can take less than three minutes to fill a mall with smoke, while it can take 30 minutes to evacuate a mall, taking into account parents with young children, the elderly and the disabled.
Despite the economic downturn, 2008 was a record year for shopping centre development and the next 12 months are forecast to be the second busiest since 1990. New centres due to open over the next 18 months are expected to add the equivalent of eight Bluewater's, the Kent site that is Britain's second-biggest shopping centre, to the UK's floor space.
This seems contradictory at a time when consumer spending in the UK continues to plummet. However, experts say that with retailers competing harder for the shrinking consumer pound, and the predicted demise of many more high street stores, the outlook is that an increasing proportion of retail activity will take place inside shopping centre complexes. With as many as 100,000 people visiting some of the larger shopping complexes daily, the safety of customers and protecting property is a key priority for retail developers. There are a number of factors to consider when planning how to protect staff and visitors from the effects of fire.
When a fire starts in a shopping centre people should be able to safely leave the building using a clearly-marked escape route.
In large or complex retail centres smoke control systems are an excellent and recommended method of keeping escape routes clear of smoke. Smoke ventilators are installed to help maintain smoke free escape routes and stairwells to enable occupants to evacuate the building quickly and safely.
The law
The managers of a retail complex, the building owners and the designers are all responsible for avoiding the risks around potential fire damage and tragedy.
In retail premises, there are a number of building regulations that must be adhered to in order to comply with UK law. These regulations relate to both life safety systems as well as smoke control.
A well designed smoke control system should be able to maintain smoke free escape conditions at low level to allow the building to be evacuated with minimum risk of smoke inhalation, injury or death.
The task is always to create a building that can be delivered on time and within budget which fully meets the requirements of the client. However, there are many other influences, such as building regulations and codes that can have a major impact on the design.
The Buildings Regulations 2000 (2006 edition) Volume 2 - Buildings other than dwelling houses, under shopping complexes clause 0.25, states that although the guidance provided in the Approved Document may be readily applied to individual shops, shopping complexes present a different set of escape problems. The design of units within a shopping complex should be compatible with the fire strategy for the complex as a whole.
A suitable approach is given in BS 5588-10:1991 - Fire precautions in the design, construction and use of buildings ‘Code of practice for shopping centres'. This also refers to BRE 368:1999 ‘Design methodologies for smoke and heat exhaust ventilation'. This is the current definitive document and superseded BRE 186:1990 ‘Design principles for smoke ventilation in enclosed shopping centres'.
BS 5588-10:1991, however, will be withdrawn from 2009 and is now being incorporated in BS 9999:2008 ‘Code of practice for fire safety in the design, management and use of buildings', which was released in November 2008. However BRE 368:1999 is still referred to as the main document to be used when designing smoke control for shopping centres.
One of the main challenges of installing an effective smoke control system is ensuring it fits into the space that is provided and adhering to the architectural structure of the building. There are several options for developers in terms of smoke control systems.
Natural smoke control systems
Smoke Control Services recently installed its natural smoke control systems into the 150,000sq ft, £1.7bn Westfield London development. The building's large stairwells and lobbies allowed this solution to be employed as natural smoke control systems, one of the most cost effective and most efficient methods, is suited to locations where space is readily available. These systems employ natural smoke ventilation methods to clear smoke from common escape routes and enable people to exit the buildings safely in the event of a fire.
Twenty two separate uniVent lobby ventilation shafts with associated stairwell ventilators were installed into the development. These systems comprise a low profile automatic opening hatch at the head of the stairwell and lobby exhaust shaft utilised Smoke Control Services new AOV control system.
Mechanical
For buildings where space is restricted, a mechanical solution may be the best option. Mechanical ventilation systems tend to be more expensive and complicated than their natural counterparts. In order to save time and money, Smoke Control Services has developed flexible modular solutions that can be applied to most buildings without the need for bespoke design or expensive CFD (computational fluid dynamics) modelling.
Westfield Shopping Centre
It was a race against time for Smoke Control Services when the company was contracted to provide the smoke control systems at the new Westfield London shopping centre.
In just three weeks, 22 uniVent smoke shaft systems were installed into the building's stair cores, ensuring that the centre could open on time and that the millions of customers were safe in the knowledge they would be shopping in safety.
The £400,000 contract at the £1.7bn mall was awarded by IMTECH MEICA Services, who were working for developer Westfield London.
The uniVent range is proving increasingly popular with developers attracted to fast, simple and cost effective solutions. It is a complete solution for protected lobby ventilation, containing all component parts and controls. The modular system employs natural smoke ventilation methods to clear smoke from common escape routes and enable people to exit buildings safely in the event of a fire.
Southside Shopping Centre
When Smoke Control Services was awarded the £725,000 contract at Southside Shopping Centre in Wandsworth, London, the company was presented with a major obstacle; the client wanted the centre to remain trading while the replacement upgraded smoke control system was being installed.
So in order to maintain smoke ventilation throughout this programme, a series of temporary systems were developed which were installed in the various construction phases.
The 11 month-long project was part of the former 1960s Arndale Shopping Centre's £30m refurbishment, which also included the addition of a multi-screen cinema and entertainment complex, new car park and the renewal of the retail space.
Work started with the design stage back in 1996 where they were tasked with the development of a smoke extract system to comply with current building regulations and British Standards. Close liaison with the Wandsworth Borough Council Building Control Department, and in particular the Senior Building Control Officer in charge of the project, was needed to ensure the complex building was adequately protected.
Smoke Control Services was employed by Gratte Brothers and Interior Plc, the Management Contractors, to implement the solution. The final installation featured more than 60 high temperature smoke extract fans with fire rated ductwork, automatic smoke curtains to provide internal zoning, and a comprehensive programmable controls package with the building management and fire alarm systems for fully automatic operation.
Conclusion
There are a number of specialist companies that supply smoke control systems for shopping centres. Look for systems with LANTAC-type approval which are automatically accepted by Local Authority Building Control organisations and consequently ‘fast tracked' through the planning process.
