Evacuation Planning in High-Rise Residential Buildings: What has changed?
13 September 2022
JUNE 2022 witnessed the publication of the amended Part B of the Building Regulations and with it new mandatory requirements for evacuation planning. Here, Ken Bullock explains the changes in detail.
How do you plan an evacuation process in a high-rise residential building? This question has been front of mind in the fire safety industry ever since the Grenfell Tower fire. Following years of uncertainty since 2017, with many short-term recommendations and changes to Best Practice arguably raising more questions than they’ve answered, we’re now beginning to gain some clarity as an industry.
Published on 1 June, the amended Approved Document B (Fire Safety) of the Building Regulations is a positive step in the right direction to improve fire safety in high-rise residential buildings. The amended Building Regulations aim to assist Fire and Rescue Services in England and meet recommendations from Phase One of the Grenfell Tower Inquiry.
The improvements to fire safety guidance forms part of a wider update to tighten Building Regulations and provide clearer fire safety rules for the design and construction of residential developments. With the document published just two weeks ahead of the Fifth Anniversary of Grenfell, it’s perhaps no surprise that much of the focus on the revised Building Regulations has centred on the changes to materials.
The amended Part B includes clearer safety standards for external walls of buildings including a ban on the highest risk Metal Composite Material panels for all new buildings. Metal Composite Material panels with unmodified polyethylene core, known as MCM PE, are now banned on all new buildings at any height. This follows research carried out by the Government and evidence heard at the Grenfell Tower Inquiry on the serious fire safety risks associated with this material.
The Government previously announced a ban on the use of combustible materials in and on the external walls of new blocks of flats over 18 metres in England, as well as hospitals, student accommodation and dormitories in boarding schools. The amendments now extend this ban to new hotels, hostels and boarding houses of this height.
These changes are designed to make high-rise residential buildings safer by helping to ensure that compartmentation is not compromised by unsuitable cladding, which could allow flames to bridge the gap from apartment to apartment.
As part of an evacuation plan and a fire risk assessment, it’s vital to know if a building has a ‘Stay Put’ policy that passive fire safety measures have not been compromised and this will assist in lowering the potential risk posed by defective cladding.
Secure Information Boxes
Although the changes to materials grabbed most of the headlines following the publication of the amended Part B, there are other significant amendments that meet recommendations from Phase One of the Grenfell Tower Inquiry and will strengthen the information available to Fire and Rescue Services. These include the change that all new residential buildings over 11 metres will now have to include a Secure Information Box that affords Fire and Rescue Service personnel access to important details about a building in the event of a fire.
According to the Part B amendments, the Secure Information Box should be:
*sized to accommodate all necessary information
*easily located and identified by firefighters
*secured to resist unauthorised access, but readily accessible by firefighters
*protected from the weather
Best Practice guidance can be found in Sections 2 to 4 of the Code of Practice for the Provision of Premises Information Boxes in Residential Buildings published by the Fire Industry Association.
In the Code of Practice, it states that it’s imperative appropriate care is taken to secure the Secure Information Box to prevent unauthorised access or vandalism. The Emergency Response Pack includes sensitive personal information about people with mobility, cognitive and sensory impairments, and also building systems which must be kept secure.
The ‘Responsible Person’ is responsible for ensuring that the Secure Information Box manufacturer can demonstrate that the product meets all of the security specification recommendations in this segment of the Code of Practice and that there are protocols and agreements in place with the relevant Fire and Rescue Service for the chosen Secure Information Box and access system.
Evacuation alert systems
However, arguably the most significant amendment to Part B when it comes to evacuation planning is the mandatory requirement for new residential developments over 18 metres to incorporate an evacuation alert system, offering new clarity for those involved in the design or construction of residential developments.
An evacuation alert system is vital to help Fire and Rescue Services inform residents of a change in evacuation strategy during an incident. This gives Fire and Rescue Services an additional tool to use on the ground, alongside existing methods of evacuation, thereby improving safety for residents.
To comply with the amended Part B, an evacuation alert system should be provided in accordance with BS 8629:2019 Code of Practice for the Design, Installation, Commissioning and Maintenance of Evacuation Alert Systems for Use by Fire and Rescue Services in England. The BS 8629: Code of Practice is applicable to any height of building, not just those over 18 metres.
The system recommended by BS 8629, for which Advanced and other companies have developed a bespoke solution, is relatively simple. It allows the Fire and Rescue Services to control evacuation floor by floor according to the severity and location of the fire. The guidance states that the evacuation alert control system should be installed where a ‘Stay Put’ policy is in force such that it can be used to facilitate a timely and ordered evacuation for all residents.
The amendments to Part B afford new clarity since it’s now mandatory to have an evacuation alert system in all new build high-rise structures over 18 metres. It must be standalone, with its only function being to assist Fire and Rescue Services personnel in the evacuation of the building.
Simplicity affords clarity
To ensure total dependability and system integrity, it must also be completely independent of the fire system, as well as independent from other building management systems and apparatus such as lifts, gas valves, air conditioning and smoke control systems.
BS 8629 also recommends that local Fire and Rescue Services should play an active role in the operation – and operational specification – of every new system. This helps to guarantee that it’s fit for purpose, as well as ensuring that personnel are familiar with it in readiness for an emergency situation.
BS 8629 states that the evacuation system must include evacuation alert control and indicating equipment that can be operated by the Fire and Rescue Service, along with audio and/or visual alarm devices in each apartment, providing clear evacuation signals to building occupants. Most importantly, any compliant system must be simple and intuitive such that it can provide straightforward support to Fire and Rescue Service personnel co-ordinating the evacuation of a high-rise residential building.
UK spec evacuation alert systems may appear simple, but their simplicity gives clarity. There’s no graphics-rich touchscreen or LCD display, with the system instead employing a series of vertically mounted manual switches, mirroring each floor of the building. Each switch uses LED technology to indicate whether the evacuation zone is active and to notify a fault.
While existing audio and visual devices are fully compatible with evacuation alert systems, the new BS 8629-compliant control panels are highly specialised items in their own right. Advanced’s EvacGo evacuation alert system is designed to meet BS 8629. The business is currently only one of a handful of manufacturers to offer an evacuation alert system housed within a box specially designed by Gerda Security to meet stringent anti-tamper standards.
It's important that the evacuation alert system is housed in a secure enclosure with a key so that it cannot be vandalised and meets STS205: Issue 4 Class BR2 or LPS 1175: Issue 8 B3 standard so that it’s safe for the Fire and Rescue Services to use. Access to an evacuation alert system should be via patented key only. Such systems should be for the exclusive use of the Fire and Rescue Services. Indeed, it’s vital to ensure that the evacuation alert system is clearly marked ‘For Fire and Rescue Service Use Only’.
The integrity of any BS 8629-compliant evacuation system is a key factor in its design and specification as it must be assumed that the fire will already be advanced by the time it comes into action. This means that cable infrastructure must be protected, while circuit isolators need to be installed at the entry and exit points to each zone, as well as prior to cable entry into each flat.
The precise rules differ according to the height of the structure. In buildings with fewer than ten storeys, two simultaneous faults on a single circuit should not disable the evacuation devices on more than half the number of storeys with flats. In buildings containing ten storeys or more, two simultaneous faults on an evacuation circuit should not disable the evacuation devices on more than a third of the number of storeys with flats. Any fault on a single flat’s evacuation device should not be permitted to affect any other device elsewhere on the system.
Power supplies for evacuation alert systems also need to comply with BS EN 54-4 requirements. If mains power fails, standby batteries must maintain the system in operation for at least 72 hours and 30 mins with all evacuation alert zones active. If an on-site generator is present and someone is responsible for it, standby time can be reduced to 24 hours and 30 minutes.
Regular maintenance and testing are vital to ensure the readiness and reliability of the system. Full inspections should be conducted every six months by a qualified engineer, while a yearly test must be completed on each sounder to verify its ability to function autonomously from the rest of the system.
Building Safety Regulator
The amended Part B forms a portion of a wider update to tighten Building Regulations and provide clearer fire safety rules for the design and construction of residential developments, with which it is essential to comply.
The Building Safety Act names the Health and Safety Executive as the new Building Safety Regulator in England and,, as such will enforce compliance of the Building Regulations. The Building Safety Act places formal responsibilities on those involved in the design and construction of any buildings to ensure compliance with the Building Regulations, and will give the regulator greater powers to prosecute for non-compliance.
It will be the duty of the people responsible for a building to put in place and maintain a golden thread of information, with their responsibility continuing for the life of the building.
What of the future? Although Part B affords new clarity, there’s still a further raft of fire safety measures that will follow. Amended Part B is designed to meet recommendations from Phase One of the Grenfell Tower Inquiry. Currently the Part B requirement for an evacuation alert system only covers new build high-rise residential buildings. However, since the Grenfell Tower Inquiry also recommends evacuation alert systems for high-rise residential buildings “already in existence”, further regulation may well follow.
Ken Bullock is Business Development Manager for Evacuation Alert Systems at Advanced
*Further information is available online at https://uk.advancedco.com/