Retrofitting AFSS in Social Housing Highrises

Transcription

1 East Midlands Retrofitting AFSS in Social Housing Highrises Stewart Kidd, MA, MSc, FIFireE, FIFSM Special Projects Consultant, BAFSA Protecting people, property and the environment

2 Coroners Guidance following fatal fires Common areas of high rise flats became regulated only in October 2006 Fire Safety Order 2005 Coroners Rule 43 Letters to Authorities advising them to consider use of sprinklers LB Southwark review concluded not cost effective solution for 317 tower blocks But: installing in 12 of 20 sheltered housing and 19 temporary accommodation blocks Southampton subsequently installed sprinklers in Shirley Towers and two other blocks

3 Fire Safety in High Rise Blocks: Guidance on sprinklers (1) BRE Research 2004 Report on effectiveness of sprinklers in residential premises Cost effective in buildings 11 storeys and over Possibly cost effective 6 storeys and over Building Regulations Approved Document B Required in new residential blocks over 30m Scottish Building Standards Requirement for sprinklers over 18m in apartments CFOA-sponsored (part-bafsa Funded) review of cost benefits of sprinklers by BRE; published November 2012

4 Fire Safety in High Rise Blocks: Guidance on sprinklers (2) Wales amendments to Building Regulations: AFSS in All new and converted residential accomodation Boarding houses and hostels CLG* Guidance Document: Fire safety: fire risk assessment: Sleeping accommodation There may be some safety and financial benefits in providing such a system Cost effective solution to reducing risk Relaxation restrictions in design Permits alternative approaches to satisfying building regulations and other fire safety requirements LGID report Fire safety in purpose built flats 10% of population live in high rise flats (England) 25% of fires, 23% injuries and fatalities But: Statistically no greater risk than low rise Reliance on compartmentation and stay put policy * Scottish/NI guidance is similar

5 High Rise Fire Risks and Impact Fire Risk Assessment reports Experience suggests passive measures are not being maintained Failure to ensure compartmentation not breached by installation of other services and damage Fire development in some fires supports this belief Dry risers and fire equipment often unavailable Potential for fire growth and spread Risks to other occupants of building External cladding often a factor Risks to fire-fighters Shirley Towers fatalities Arson a common cause of fires often in communal areas Financial and social impact of incidents Authorities Residents Community Liability for owners

6 Fire and Rescue Service Response Additional risks to fire service personnel in high rise premises Risk of prosecution under H&S legislation Guidance and fire service policy to establish bridgehead two floors below level of fire Staffing and response implications All equipment and personnel to be in place before fire fighting commences Estimated time to achieve this for higher levels is approximately 20 minutes (Herts F&RS study) Significant time delay compared with fire in low rise premises with associated longer period of fire growth and increase of spread and intensity Where compartmentation is compromised this can be critical Access issues Water supplies

7 Impacts of Fires : Case Studies - Waddell Court, Glasgow Major refurbishment programme million cost Fire improvements did not include sprinklers 16 December 2009 Serious fire on 5 th floor One fatality and two injuries Fire spread to upper floors Residents rehoused for up to 11 months Total costs of rehousing, refurbishment and loss of rental income = 2.6 million Only 1 of the 77 residents had house contents insurance so claims made on landlord

8 Impacts of Fires Case Studies South Ayrshire District Council South Ayrshire Council Fitted sprinklers as part of a refurbishment programme in 2002/3 in all high rise and selected sheltered housing Subsequently experienced four* kitchen fires in individual flats Minimal water damage Refurbishment limited to redecoration of flats involved No decanting of other tenants *At just before midnight on Monday 25 September 2017, Scottish Fire and Rescue Service attended a living room fire at a 13 storey block of flats at Riverside Place, Ayr. Four breathing apparatus wearers were committed to the fifth floor flat and on arrival they found that the fire, which was in some bedding on the living room sofa, had been extinguished by a single sprinkler.

9 Relaxations and compensations Design freedoms if undertaking major refurbishments Building Regulations/Standards approval and compliance Relaxations permit changes to internal layout BS 9991:2011 Permits relaxation of standards for means of escape, levels of fire resistance and fire alarm standards Relaxation of fire service access requirements Hydrant locations/proximity Northampton House Former office block converted to flats Sprinklers only way to satisfy Building Regulations and make conversion commercially viable Three fires since occupancy, residents escaped uninjured

10 BS 9991 Variations when AFSS is provided Permitted variations of guidance Where a sprinkler system or watermist system is fitted throughout a house, the internal layout of the ground floor may be open-plan and in a four-storey house, a second staircase is not required. Where a flat is fitted with a sprinkler system and an LD1 fire detection system in accordance with BS , it may have an open-plan living room with inner rooms leading off it (see 9.7). Where sprinklers are fitted throughout a house or block of flats, the minimum distance between the side of the building and the relevant boundary may be halved. Where attendance time of the local fire and rescue service is expected to be no more than 10 min: a) the distance between the fire appliance and any point within the house (in houses having no floor more than 4.5 m above ground level and having a sprinkler system throughout) may be up to 90 m; b) the distance between the fire and rescue service pumping appliance and any point within the house or flat may be up to 75 m (in houses or flats having one floor more than 4.5 m above ground level and a sprinkler system installed throughout). With the exception of sheltered and extra care housing, where a block of flats is fitted with a sprinkler system in every flat, the maximum travel distance for escape in one direction only may be increased from 7.5 m to 15 m and for escape in more than one direction it may be increased from 30 m to 60 m.

11 Post Lakanal Fire Activity Lakanal House Fire, 2009: Report by Chief Fire Advisor (E&W) to CLG It is not considered practical or economically viable to make a requirement for the retrospective fitting of fire suppression systems to all current high-rise residential buildings. This resulted in concerns from sprinkler industry and others Sprinkler Coordination Group approached CLG Housing Directorate about a pilot study. Initial offer of assistance CLG withdrew support and involvement even the observer SCG issued a scoping document South Yorkshire FRS/Sheffield Homes proposal BAFSA to manage project Steering Group formed to manage project

12 The Callow Mount Project: Retrofits Justifed? Callow Mount retrofit : major report 6000 copies + DVD circulated Provided evidence for authorities to consider the potential cost- benefits of using sprinklers Housing authorities and associations now using a targeted approach in both high and low rise premises: Vulnerable residents and extra care facilities As part of major refurbishment programmes To address specific fire safety concerns such as single staircases Compare benefits with other fire safety measures Many installations (eg Staffs, London, Scotland, Wilts are F&RS funded

13 Real Costs of Retrofit Installation of Sprinklers Location Total System Cost Cost per Flat/Home Comments Callow Mount 55, heads per one bedroom flat Includes bin store, communal room and office Bryn Arfon Housing Assoc 80, heads per one/two bedroom flat Includes communal areas, bin and cycle stores and rooftop pavilion Sheffield Low Rise 1,152, heads per home includes 1, 2 and 3 bedroom units

14 Sprinklers as Compensation: BS 9991 There are occasions when a fire suppression system is used as a means of demonstrating compliance with building regulations or to compensate for, or overcome, circumstances where a building is unable to achieve compliance with guidance issued in support of building regulations. Consultation between designer and any necessary AHJs, Category of system and design density, agreed and recorded Fire safety strategy to support System resilience measures appropriate to the risk, agreed and recorded

15 Scottish Fire and Rescue Service Data Fires in High Rise Flats Numbers of fires have fallen from high of 499 in 2009/10 to 238 in 2015/ % of these fires were in unsprinklered flats, resulting in 15 deaths There were 56 fires in flats with sprinklers with no deaths One fire in a sprinklered flat resulted in a single injury

16 Application of BS 9251 in UK

17 Initial Considerations Before undertaking the design of a BS 9251 residential sprinkler system for a specific property, the designer should evaluate the following factors before starting work on the project, obtaining specialist advice where necessary: the risks to be protected, including the fire loading the type of occupancy of the property the water supply requirements and availability any special circumstances Whether the system is being used as a form of alternative compliance NOTE 1 In some buildings or parts of buildings, a higher level of protection might be required than that provided in BS 9251

18 Application of BS 9251 to new build in UK Legislative Requirements Welsh Regulations all new domestic and residential properties All new high rise flats over 18m, care homes and sheltered housing in Scotland All new high rise flats over 30m and England Loft conversion and open plan layouts Housing Association and local authority policies

19 BS 9251: Category classifications Three categories by occupancy building type Single family dwellings, HMOs, B & B, Small Boarding Houses, Blocks of flats up to 18m and 2400 m2 Blocks of flats over 18m, small residential care premises up to ten beds, sheltered housing and extra care housing Larger residential care premises, dormitories and hostels Outside these criteria, BS EN 12845: 2015 should be used

20 Development of design density requirements Recognition of conservative approach to earlier standards Acknowledgement of international standards (NFPA 13D/R and INSTA) Consideration of size and range of premises covered by BS and others Need to gain acceptance from the regulators Compromise solution justified by technical analysis: Categorize by building type/size Appropriate water requirements for risk Additional requirements where sprinklers are used to compensate for other fire protection measures or for compliance with Building Standards

21 BS 9251 Design Density Previous standard used two defined flow rates one for domestic. and one for residential New standard uses minimum design density per category and identifies: Number of design sprinklers Minimum design density Duration of water supply Lower design density for buildings where sprinklers are additional fire protection measures or in compliance of Building Regulations/Standards 2.04 mm/min or 2.80mm/min Higher design density where used as a compensatory feature 2.80 mm/min or 4 mm/min

22 BS 9251 Extent of sprinkler protection Sprinkler protection should be provided in all parts of the premises. However, unless required by a fire strategy or risk assessment, the following may be excluded: bathrooms with a floor area of less than 5m 2 ; cupboards and pantries with a floor area of less than 2m 2 or where the least dimension does not exceed 1m; attached buildings such as garages and boiler houses without direct access from within the protected building; crawl spaces; ceiling voids; external balconies* permanently open to the outside; uninhabited loft/roof voids. *But: Concerns have been expressed about this exemption following fires on balconies in the Arabian Gulf and Australia

23 BS 9251 Water supplies Sprinkler systems should be connected to a reliable and sustainable supply, for example: mains water supply: mains pressure only; mains water supply boosted by a pump; stored water supply: pump supplied from a water tank; regulated pressurized vessel; gravity-fed stored water system. Clauses to cover the technical recommendations for these types of supply. Skid-mounted pump unit with tank over

24 BS 9251 Pumps Suitable for use on sprinkler systems Wired to be protected from electrical supply failure Can be advantageous to combine pump to supply water to domestic and sprinkler system. (Such pumps are in regular use and should domestic supply fail it is readily noticed and acted upon) Dedicated sprinkler pumps should have monthly self-test feature and alarm on pump fault or electrical supply failure

25 Pipework Pipework can be: Black steel Copper CPVC (approved for sprinkler use) CPVC should be installed only by company competent to do so 15/06/

26 BS 9251 Frost Protection Antifreeze is flammable. It has to be sufficiently diluted and thoroughly mixed. Only approved premixed solutions that can be evidenced as suitable for sprinkler systems should be used. Only glycerine-based anti-freeze solutions may be used with plastic pipe and fittings. Glycol-based anti-freeze solutions should not be used in CPVC systems as it can damage the plastic. The water supply company should be consulted regarding the fluid categorization and the suitability of backflow prevention arrangements prior to installation. Note: Lagging and trace heating remain as the most viable options

27 BS 9251 Alarm Connected to independent internal alarm, or: Interfaced with automatic fire detection and alarm system, this interface should comply with the relevant part of BS Sprinkler alarm should be clearly distinguishable from fire detection system Vulnerable persons alarm should have remote monitoring, sprinkler system activation should be treated as a confirmed fire.

28 System data label A label or notice should be attached or fixed adjacent to or on the sprinkler riser next to the main sprinkler stop valve as a permanent record of a system s design data.

29 Maintenance Maintenance for AFSS is relatively simple and low cost. Annual check to ensure water supplies are still appropriate Visual inspection to ensure sprinkler heads have not been obstructed or painted Self-testing systems are available with real time reporting of conditions Landlords staff can be trained to undertake the reviews

30 Watermist Systems (1) Watermist can be installed in residential premises using BS 8458: 2015 Care should be taken with claims such as meets the requirement of BS 8458 or equals BS 8458 Watermist systems cannot be designed to BS 9251 Watermist heads cannot claim compliance with BS 9252 Systems should only be installed by competent persons who hold a third-party accreditation for this Presently, only FIRAS Warrington runs such a UK scheme:

31 Watermist Systems (2) Watermist systems in residential and domestic systems are very similar to sprinkler systems but operate at a higher pressure (normally using pumps). Cylinder-supplied systems use very high pressure inert gas (Cylinders to comply with BS EN ). If the building is taller than 45m then a watermist system to BS 8489 Part 1 should be considered Section 5: System actuation is automatic via glass bulb or fusible link initiated by heat generated from the fire Mist systems use less water - for domestic occupancies water storage should allow 10 minutes discharge. In residential occupancies 30 minutes

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33 And they work! 15/06/