GUIDANCE | FAADES TALL ORDER Following the ban on the use of combustible materials in some building faades, two industry bodies have come together to produce guidance on these legislative changes. Liza Young looks at the wider implications of the new regulations COMPETENCY IS KEY The Society of Faade Engineering is in the process of altering the way it scrutinises its members, and aims to establish a framework enabling it to recognise chartered status. David Metcalfe says: The SFE recognises that it is increasingly important that individuals are able to demonstrate their competencies, and our long-term ambition is to work towards chartered status to recognise those highly qualified and experienced individuals. Saverio Pasetto says that some members have already obtained CIBSE chartership by applying as faade engineers through the SFE. The discipline has been recognised as an important aspect [of building services engineering] and we are working on a framework that will enable the SFE to deliver chartership status in the future. I n June 2017, after the devastating fire at Grenfell Tower, construction industry practices and competency were called into question, and wholesale change was inevitable. The following year, in November 2018, the UK government announced changes to the Building Regulations in England, implementing a ban on the use of combustible materials in the external walls of certain highrise buildings in England. In response, the Society of Faade Engineering (SFE) and the Centre for Window and Cladding Technology (CWCT) have come together to develop technical guidance offering a practical and pragmatic explanation of the new regulations. The principal challenge, says the guides main author, David Metcalfe, was taking the wording of the legislation and applying it to modern, complicated faades. Although the amended Regulation 7 bans the use of combustible materials in external walls more than 18m high in residential buildings, it acknowledges the vital role that some combustible materials play in the performance of modern faades especially when it comes to meeting other regulated requirements, such as thermal performance and weathertightness. Subsequently, it introduces some exceptions. However, the SFE and CWCT say these exemptions do not fully recognise the complexity of modern building envelopes, and leave some ambiguity and uncertainty over materials that may or may not be used, and the circumstances in which they may be used. In developing the guidance, the CWCT and SFE faced numerous challenges, including interpreting definitions and terminology, as well as reconciling the sometimes conflicting requirements of the wider regulatory framework that buildings must meet. New legislation The amended Regulation 7(2) bans the use of materials that do not meet the specified reaction to fire requirements in any part of the external wall of so-called relevant buildings, to ensure they are safe from fire. A relevant building is one with an occupied storey at least 18 metres above ground level, and which contains one or more dwellings, an institution such as a hospital or a room A single material could have a different function depending on how, and where, it is used in the building for residential purposes, such as student accommodation. Put simply, all components need to be constructed from materials that achieve European reaction to fire classification A2-s1, d0, except those that do not pose a significant contribution to fire risk, or for which there are no suitable alternatives, as referred to in the exceptions. This is significant because, in recent years, some combustible materials have been used to improve thermal performance and airtightness, or reduce defects as a result of water leakage, and so on. The amended regulation seeks to dramatically reduce their use, says Metcalfe, who is director of CWCT, a board member of the SFE, and chair of the SFE Fire Committee. To add to the challenge, other requirements related to buildings thermal performance and environmental impact must also be taken into account, says Saverio Pasetto, head of 26 October 2020 www.cibsejournal.com CIBSE Oct20 pp26-29 Facade guidance.indd 26 25/09/2020 14:43