The Grenfell Tower fire in 2017 was the deadliest structural fire in the United Kingdom for almost 20 years. Since the Grenfell Tower tragedy, fire has been under public inquiry. May 2018 saw Dame Judith Hackitt present to Parliament and challenge construction, that an urgent and comprehensive review of our building regulations and fire safety was required with immediate effect.
In the wake of 72 people losing their lives, Dame Hackitt called for wholesale culture change in the construction industry and a regulatory system that assigned responsibility and held people to account.
In all, her report contained 53 recommendations and she warned at the time that the industry should not be allowed to pick and choose which to implement; there should be no compromises with people’s safety ever again.
Building regulations ensure that new buildings, renovations, extensions and conversions both in domestic and/or commercial structures are going to be safe, healthy and high-performing. Regulations also cover specific topics within the built sector: structural integrity, fire protection, accessibility, gas safety, electrical, energy performance, acoustic performance and protection against falls.
Standards which are particularly aimed at basements and below ground structures are: protection against the ingress of water, protection against contamination (including methane, carbon dioxide, volatile organic compounds (VOCs) and radon gas), ventilation, drains, along with others.
Building regulation approval is required for the construction, adaptation and extension of all basements and below ground structures.
Applying for building regulation approval is a relatively straightforward process. Application can easily be made to [your] local building control team by email or via their online portal.
The Basement Information Centre offers a comprehensive guidance and in-depth analysis on all building regulations related to basement construction, I would strongly recommend this publication to anyone seeking a valuable resource (www. https://www.basements.org.uk/TBIC/Building-Legislation/Building-Regulations.aspx).
Reaction to fire, often called the EuroClass system gives building products a classification. The ‘Reaction to fire’ classes tests three properties of the building material: spread of fire, smoke intensity and burning droplets. Most building materials sold on the European market must be assigned a file indicating its fire resistance based on a EuroClass rating system. There are 7 EuroClasses of reaction to fire performance for construction products which extend from A1 to F. I would strongly recommend any designer, specifier or constructor to check the source of products you are planning to specify, use or install. All manufacturers should be able to provide you with their Product Fire EuroClass rating, CE Mark Certification and Declarations of Performance (DoP) as a minimum.
It is essential for building products to meet a variety of performance requirements. Depending on the type of material and its intended application, specific fire performance properties are tested.
The Building Research Establishment (BRE) offer a wide range of fire resistance testing (from British to European fire test standards) for construction industries for the purpose of complying to UK Building Regulations or for European Classification and CE Marking.
Delta undertook this service many years ago. In fire testing our products we can have a better understand how they perform during a fire. The benefits of these fire resistance assessments allow us to share with designer’s test data to ensure safe future construction.
Important considerations should be given when designing a basement or below ground structure on how it will behave during the event of fire. Whilst a basement is not counted when assessing the numbers of storeys of a property for fire resistance and means of escape, it should be factored into design and be a key consideration. Typically, 30 minutes fire resistance is required for a two-storey house over a basement, which increases to 60 minutes where the number of storeys is four or more.
Designers should consult the relevant approved documents to check requirements related to their specific design and for other housing types.
Fire separation between a basement and upper storeys is required if the height of the top floor is more than 4.5 metres above the lowest external ground level. This situation is only likely to occur in two-storey dwellings if the basement floor level is less than 1.2m below the external ground level or located on a very sloping site.
The walls and floor between garages and houses also require 30 minutes fire separation which also applies if located in a basement.
Ground floor flats or maisonettes with a basement level and direct main entrances require no fire separation over and above typical fire separation between apartments.
Habitable rooms in basements require a safe means of escape. The maximum distance that people must travel, from any point in a building to a place of safety, is usually termed the “travel distance”. A safe means of escape from a basement could be provided by the main staircase of a structure, provided it is protected and connected to a final exit. Alternatively, escape can be provided by an additional stair offering an alternative final exit. Escape through windows is permissible if designed to permit escape as defined by the building regulations.
It is worth noting that non-habitable rooms in basements, such as kitchens, utility rooms and bathrooms can be classed as inner-rooms and depending upon the layout of the structure may not require separate means of escape.
It is permissible to exit into gardens or courtyards, provided they have an exit to a place of safety or are greater in area than the height of the structure.