Changes to the built environment through sustainability and some implications for fire safety

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1 Changes to the built environment through sustainability and some implications for fire safety Prof David Charters, PhD, CEng, FIFireE. MIMechE Director of Fire Engineering Visiting professor of fire risk analysis at the University of Ulster

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4 Innovation Park

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13 Overview Introduction Modern methods of construction Potential implications Possible ways forward Summary

14 Modern Methods of Construction (MMC) A reaction to a number of economic and policy drivers: Strategic (demographic) Modern built environment coupled with skills shortage Environmental thermal performance, energy conservation, use of brownfield sites, whole life costing, minimising waste Economic speed of construction

15 The UK needs the benefits of modern methods of construction

16 MMC (continued) Many of the issues that impinge on fire safety are a consequence of meeting/surpassing regulatory requirements in other areas ventilation, thermal performance A great deal of effort has been put into demonstrating the effectiveness of MMC in meeting the strategic/ regulatory/ policy goals Fire performance has been considered in terms of simple regulatory compliance Some potential concerns in relation to performance of products and systems Are the requirements of ADB appropriate?

17 Promotion/Marketing of MMC (continued) The commercial and strategic case for MMC has been well made and will not be dealt with further in this presentation: DTI Global watch mission Review of housing supply (Barker Report) National Audit Office report BRE Offsite MMC Seminar Loughborough University Report Home In Publications Parliamentary postnote Barker 33 Cross-Industry Group report The aim is to focus on performance issues and the relationship between MMC and the regulatory system

18 Identification of different types of MMC Systems steel, timber, SIPS and concrete building systems Facades new materials and systems Products ICF, Engineered Joists,

19 Identification of different types of MMC Use of new materials New materials used for thermal insulation Thermoset: Polyurethane foam (PUR) Polyisocyanurate (PIR) Phenolic foam Thermoplastic: Expanded polystyrene (EPS) Extruded polystyrene (XPS) Multi-layer aluminium faced plastic sheets Other recycled news print, natural fibres such as sheep s wool May form part of external walls, insulation within internal walls, or part of external cladding system

20 Identification of different types of MMC Use of new materials (continued) Most recent version of Approved Document B of the Building Regulations restricts the use of insulation material (to products of limited combustibility) for buildings > 18m for external wall construction There is no corresponding equivalent for internal wall linings. Guidance possibly originally based on the widespread use of non-combustible materials for internal walls. Requirement relates to the insulation in the cladding ventilation Thermoset and Thermoplastic materials may be used in linings of external walls remote from the cladding.

21 (UK) Regulatory requirements and suitability of current methods of test and assessment Reaction to fire BS476 Parts 6 and 7 / BS EN ISO and BS EN (classification according to BS EN 13501:1) Fire resistance BS476 Part 20/21/22 / BS EN 1363, 1364 and 1365 (various parts) (classification according to BS EN 13501:2)

22 (UK) Regulatory requirements and suitability of current methods of test and assessment Internal and external linings control of products

23 Suitability of current methods of assessment Internal and external linings reaction to fire tests (BS 476 Part 6 and BS 476 Part 7) Relationship between heat flux from test and real fire situation Need to ascertain system performance not just surface linings

24 Regulatory requirements Provide sufficient fire resistance for structure dependent on height and type of occupancy (Firecode HTM 05-02/Table A2 AD-B): Fire Resistance BS476 Parts 20, 21,22 Standard fire exposure Isolated elements

25 Suitability of current methods of assessment System performance? robustness, interaction, connectivity, concealed fire spread Reaction to fire issues? performance of new materials, system performance (built up or composite systems) Toxicity and smoke production?

26 Industry concerns Mortgage Lenders Based on previous experience with post-war system built housing Experiences in the past may well affect lenders willingness to lend on new construction types which are unfamiliar and which may appear to exhibit some of the same characteristics as those they have had problems with in the past (Council of Mortgage Lenders, Modern Methods of Construction,

27 Industry concerns Mortgage Lenders Durability track record? Whole life costs affect on demand over the longer term Repairability comparable with traditional construction types? Projected lifespan sufficient to maintain security Adaptability Availability of insurance short and long term Maintenance of demand

28 Industry concerns Insurance industry Insurers concerned about the absence of an appropriate risk profile to apply to the various forms of MMC The risk profile of a property number and cost of expected claims is the key piece of information that insurers need to underwrite the risk Perils ranked by loss adjusters according to frequency and cost: Fire ranked highest Water leak, storm and flood also significant (

29 Industry concerns insurers concerns Range of perils that affect buildings have been identified by the insurance industry: Flooding Driving rain Fire: Single room fire breaking out through window, damaging the internal linings and external cladding above the window Internal impact damage that exposes insulation material (e.g. moving furniture or DIY hospital porters/ handrails ) Subsidence Windstorm Security: Attempted theft by forcing doorframe to gain access The above scenarios have associated costs for repair reassurance required that comparative costs for MMC are not disproportionate to the event.

30 Fire Safety Issues experience from real fires and relevant research concealed fire spread Cavity barriers Fire stopping Combustible linings Melting of thermal insulation

31 Fire Safety Issues experience from real fires and relevant research alternative modes of failure Connection between floor and wall elements Not currently assessed Potentially more of a problem for MMC screws, rivets, very little direct bearing, large deflections System performance needs to be evaluated

32 Hotel, West Country Poor fire stopping led to rapid spread from the seat of the fire in the centre of the building Fire during construction - non-traditional construction, no further relevant information

33 Apartment building, London Small fire in patio area external wall construction failed to provide adequate resistance to the passage of smoke between apartments and floors. Amount of damage out of proportion to the size of the incident

34 Swimming baths, Midlands Rapid fire spread within roof system Unseen spread of fire automatic detection did not operate until after the emergency services responded

35 Residential development Fire during construction Occupation of partly completed buildings Speed of fire spread implications for construction sequence

36 Alternative methods of test and assessment LPS 2020 developed to provide reassurance to key stakeholders that the residential buildings can demonstrate compliance with the Building Regulations, have a satisfactory level of durability, repairability and maintainability Possible use of enhanced standards (LPS 2023 Fire performance) LPS 1501 is a test standard to cover buildings including residential buildings and non residential buildings BS8414 test method for external cladding systems

37 Alternative assessment procedures BS8414

38 Main Face Main Face Wing Wing Combustion Chamber 2000 Combustion Chamber

39 Alternative assessment procedures LPS 1181, LPS 1581, LPS 1195, LPS 2023, LPS 1501

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41 Fire compartment Compartment wall Compartment floor

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43 Future research priorities Do we need to do anything? Does LPS 2020 adequately address key stakeholder concerns? Do we need to focus on generic systems, products, materials or some combination of each? Do we have sufficient information to enable informed decisions to be made?

44 Future research requirements Food for thought Cavity barriers and fire stopping how do we currently assess the performance of cavity barriers? Do we need to consider fire performance from both sides? This is a recognised problem for all forms of construction but is particularly important where multiple cavities are present and where cavities are in intimate contact with combustible material. Façade performance Is the reference to BS8414 in the proposed revision to ADB sufficient? Should this be compulsory for buildings over 18m rather than optional? Is this an insurance issue?

45 Future research requirements more food for thought A number of organisations collate information on fire deaths, cause of fire and costs of fire damage Lack of co-ordination between various organisations More information required on the nature of the construction and the age of the property Require maintained database of fire statistics which can be interrogated with respect to type of construction This would be of great use to all key stakeholders

46 Future research requirements (further) Food for thought SIPS panels performance in fire similar situation to Appendix F of ADB? Engineered Joists Comparative performance under realistic support and loading conditions. Concrete fire tests ICF, high performance concrete, cement replacement materials, high strength jointing compounds

47 Summary The UK needs the benefits from ICPT. Fire safety in buildings is unique and integrated. ICPT offers significant benefits and potentially some new fire safety challenges. It is up to all of us to make sure that buildings achieve these benefits safely.

48 Questions/Discussion