The Building Regulations - Fire
Building Regulations define the minimum fire safety requirements of building elements or components in two main ways.
The basic concepts are the same in all the regions of the UK and Ireland, but it is worth noting that, because of its inherent strength, pre-finished steel roof and wall cladding complies very easily with the fire regulations in most situations.
Fire performance requirements are a function of:
- Building use. For example offices, industrial, hospitals.
- Building storey area. This storey area jointly with the building type, defines whether compartments are required.
- Building height. There will be different provisions for high-rise building in the UK. High-rise buildings are considered to be over 18 m in height.
- Building location. Boundary buildings, those less than 1 m from a boundary, will have different provisions in terms of the external surface of walls and performance of foor coverings.
Based on these criteria, the requirements are expressed in terms of minimum fire performance in up to three areas.
- Fire resistance. This applies to systems such as panels or profiles rather than building materials. It measures the ability of a system to prevent the penetration of hot gases and flames as well as its ability to reduce the temperature rise on the unexposed side of the fire and therefore prevent fire spread through radiated heat.
- Roofs’ performance in terms of exposure to external fire.
- Surface spread of flame (also called reaction to fire in EN standards).
Following the decision to harmonise standards in the construction sector across Europe, the European Union commissioned more than 500 harmonised standards from the Comité Européen de Normalisation (CEN). At this time, only a fraction of the total has been published.
British and Irish regulators have already introduced references to some of the future European standards in the Building Regulations. However, most of these fire standards are still at the draft stage and have yet to be agreed upon.
As a consequence, it is currently impossible to use European fire standards to demonstrate compliance with the Building Regulations. At the moment, the only way to demonstrate compliance is still to use fire performance as determined by BS 476.
A co-existence period will follow publication of the EN in the Official Journal. During this period, both BS 476 and the EN can be used to demonstrate compliance. At the end of the co-existence period, BS 476 will be withdrawn, and fire performance will have to be quoted against EN. The co-existence period is normally 21 months. However, fire safety is such a critical and complex issue that it is very possible that the coexistence period will be significantly longer.
Moreover, some European standards, such as the one used to determine the resistance of roofs to external fire exposure (DDENV 1187), have not yet even been introduced in the building regulations. The proposed European standard is more lenient than BS 476-3, and could therefore lead to the introduction of products into the UK or Ireland which are less safe.
In the light of these considerations, BS 476 will still not be superseded by the European standards before 2007 at the earliest.
