Cladding Remediation Programme: Single Building Assessment specification

Appendix E. Risk Factors Arising from Fire Strategy/Fire Hazards (Including Fire and Rescue Service Intervention)

The following images show Table F.1 of the PAS 9980 document which covers risk factors arising from fire strategy/fire hazards. This is a non-exhaustive list of examples of common factors that influence the ability of occupants to escape once a fire occurs and spreads via the EWS to other parts of the building. It also gives a list of examples of the ability of the SFRS to intervene effectively.

Note that no single row in the Table F.1 provides a definitive answer on risk. Whether an entry is considered positive, negative or neutral is purely indicative of the potential influence it might have. A competent assessor uses their judgement to determine actual relevance of each factor. Where numerical values are given, these are only intended to be indicative as to the possible influence the particular factor might have in a risk based assessment.

Where a risk factor is marked with an asterisk (*), this indicates that it is notably more of a positive influence.

Figure C.1 – Table F.1 of PAS 9980 – Risk factors arising from fire strategy/fire hazards (including limitations of fire and rescue service intervention)

Where a risk factor is marked with an asterisk (*), this indicates that it is notably more of a positive influence.

F.1 Occupancy

Note This relates to the predominant occupant type within the building, recognizing that the occupancy might be mixed.

Positive

Accommodation in which there will be short evacuation times

Note 1 Principally, this is likely to apply to student accommodation, which is managed on‑site and has a fire detection and fire alarm system that can support escalation from a stay put evacuation strategy to a simultaneous evacuation strategy, in given circumstances.

The building’s FRA would be expected to confirm that this is the case.

Note 2 There might well be occupants with varying degrees of physical disability. Unless the accommodation is predominantly occupied by people requiring assistance to escape in a fire, it would remain a positive risk factor.

Neutral

General needs housing

Note In general needs housing, there might well be occupants with varying degrees of physical disability in line with the general population. Unless the accommodation is predominantly occupied by people requiring assistance to escape in a fire, it would remain a neutral risk factor.

Negative

Specialized housing:

• sheltered/retirement;
• extra care; and
• supported

Note 1 These housing types are indicative; terminology applying to specialized housing varies. See also BS 9991 and NFCC publication Fire safety in specialised housing [31].

Other accommodation in which there will be long evacuation times

Note 2 This refers to accommodation that is predominantly occupied by people who are likely to require assistance to escape in a fire. It does not apply to general needs housing or student accommodation, in which there most likely will be at least a proportion of such people but not a predominance.

F.2 Evacuation strategy

Positive

Immediate, total evacuation (or with simultaneous evacuation and a suitable investigation time)

Phased evacuation (see Note)

Note Phased evacuation could be a positive or neutral depending on the extent of the phased evacuation protocol and how it is managed (e.g. in student accommodation).

Neutral

Stay put

Phased evacuation (see Note)

Note Phased evacuation could be a positive or neutral depending on the extent of the phased evacuation protocol and how it is managed (e.g. in student accommodation).

Negative

-

F.3 Escape route design

Note For the purposes of an FRAEW, deficiencies identified in an FRA or fire door condition survey in respect of the doors to flats or escape routes are expected to be rectified and are not taken into account.

Positive

Access to more than one staircase for escape, where it is not possible for the same fire to affect all escape routes*

Access to more than one staircase for escape

Note Where it is foreseeable that the same fire could spread to affect all of the escape staircases, the likelihood of this happening in relation to the speed of fire spread, and the timescale needed to evacuate the building, need to be taken into account.

Neutral

Single staircase, with lobby approach

Extended travel distances ≤15 m (with supporting smoke control)

Note Although generally this is considered as neutral, as with all risk factors, whether this is appropriate needs to be considered in the context of the actual building under consideration.

Negative

Single staircase for escape, with staircase rather than lobby approach

Extended travel distances ≤15 m (without supporting smoke control)

Extended travel distances >15 m (with or without supporting smoke control)

Note 1 A single staircase is permitted for blocks of flats under building regulations and it is not implied that such an arrangement is unsatisfactory.

Open balcony approach to flats

Note 2 An open balcony approach is permitted for blocks of flats under building regulations and it is not implied that such an arrangement is unsatisfactory.

Open balcony approach to flats, with aggravating features such as combustible decking.

Final exits from escape routes in close proximity to external wall construction that could result in danger to escaping occupants in the event of burning material or debris falling from a fire involving the external walls above

Note 3 In this situation, burning material and debris from the fire above can also pose a danger to firefighters entering or leaving the building.

F.4 Compartmentation

Positive

-

Neutral

Adequate compartmentation in line with the expectations for a block of flats

Negative

Inadequacies in the compartmentation, e.g. between flats, that have been addressed by other compensatory measures

Note This only considers a permanent situation in which there is a shortfall in the standard of compartmentation compared to normal expectations for a block of flats. For the purposes of an FRAEW, deficiencies identified in an FRA or compartmentation survey are expected to be rectified and are not taken into account.

F.5 Smoke control

Note Whether smoke control arrangements are positive or negative very much depends upon the context in which vents, for example, are located in relation to a potential fire involving combustible elements of a building’s external walls. Where due to the remoteness of the vents, spread of fire and smoke is unlikely to compromise the effectiveness of the smoke control system, this is potentially positive as an efficient smoke control system will prolong the tenability of staircases both in relation to means of escape and also intervention by the fire and rescue service. Inlets and outlets for mechanical systems, where located on the roof of a building, might possibly be considerably less prone to being affected by an external wall fire than, for example, AOVs or other vents on the elevations.

Positive

-

Neutral

-

Negative

Arrangements in which openable windows, AOVs or inlets and outlets of mechanical systems are in close proximity to combustible cladding or otherwise exposed to fire and smoke spread from the external envelope that could compromise the effectiveness of the smoke control system or allow a route for fire spread back into the building

F.6 Fire detection and fire alarm system

Positive

System with automatic detection throughout the building, including within flats, capable of immediate full evacuation, configured as:

• common area coverage, also with detectors at least inside flat entrance halls (local warning within flat from domestic smoke/ heat alarms); or
• common areas and throughout flats*; or
• monitored by staff on a 24 h basis or by an alarm receiving centre (ARC)*

Neutral

Domestic smoke and heat alarms within flats, Category LD1*

Domestic smoke and heat alarms within flats, Category LD2 or LD3

Note 1 LD1, LD2 and LD3 are categories of fire detection and fire alarm systems in domestic premises defined in BS 5839‑6. ADB ([8], [9]) guidance for new flats recommends at least Category LD3 for any flat, but a higher category in some circumstances, with LD2 being the minimum recommended for existing flats in BS 5839‑6. LD1 has the benefit that fire is detected within any room (other than bathrooms and toilets) with openings onto the external façades of the building, thus giving the early warning of fire to occupants and, potentially, an early summoning of the fire and rescue service.

Evacuation alert system for use by the fire and rescue service

Note 2 These systems are provided to enable the fire and rescue service manually to evacuate a building operating a stay put strategy. At the time of publication of this PAS, such systems are in their infancy. Such systems include those conforming to BS 8629, or a fire detection and fire alarm system conforming to BS 5839‑1 (or BS 5839‑6, Grade A) configured to sound an evacuate alert in all flats on operation of a manual control. While such a system might be beneficial, caution is needed to avoid overreliance on the fire and rescue service. This would be a positive risk factor if present in conjunction with a fire detection and fire alarm system monitored at an ARC.

Negative

-

F.7 Fire suppression

Note The weight attached to the presence of any fire suppression system in the building needs to take into account whether the system extends into, for example, any car parking area below the flats such that the scope for a vehicle fire to ignite combustible material on the external walls of the flats is mitigated.

Positive

Sprinkler system throughout building, conforming to BS EN 12845*

Domestic sprinkler/watermist system in each flat:

• conforming to BS 9251 (sprinklers);
• conforming to BS 8458 (watermist)

Neutral

Local protection within flats, e.g. cooker hood protection or other partial protection system

Negative

-

F.8 Firefighting facilities

Note 1 Access for firefighting vehicles is only one aspect relevant to effective fire and rescue service intervention. Annex E gives broader consideration to fire and rescue service intervention and the limitations that can apply to achieving this.

Note 2 A source of benchmark guidance that could be used is ADB ([8], [9]), but advice might need to be taken from the fire and rescue service.

Note 3 Suitable access to facilitate effective fire and rescue service intervention is fundamental to mitigating the fire risk posed by external walls on buildings below 18 m down to a tolerable level. However, even in low rise buildings, the difficulties of tackling a fire involving external wall construction when operating at ground level using typically available equipment need to be recognized (see Annex E).

Positive

Good access for firefighting vehicles

Note This is where access exceeds benchmark guidance on access for firefighting vehicles, taking into account the size of the building (floor area), height of the building and whether fire mains are present in the building. This might be the case where access is possible to all elevations of the building.

Neutral

Adequate access for firefighting vehicles

Note This is where access is possible in line with benchmark guidance on access for firefighting vehicles, taking into account the size of the building (floor area), height of the building and whether fire mains are present in the building.

Negative

Poor access for firefighting vehicles

Note This could include where access is severely restricted or there is no access directly adjacent to the building, or where there is no access for high‑reach appliances.

F.9 Rising mains

Note 1 Rising mains are only one aspect relevant to effective fire and rescue service intervention. Annex E gives broader consideration to fire and rescue service intervention and the limitations that can apply to achieving this.

Note 2 There is no requirement for rising mains to be fitted in new buildings below 18 m in height, unless the distance between the fire appliance to all points within each flat exceeds 45 m on a route suitable for laying hose.

Positive

-

Neutral

Suitable rising main present

Note 1 While rising mains have been a requirement for new buildings above 18 m in height for many years, their role in terms of the effectiveness in intervention by the fire and rescue service is a significant factor.

Note 2 “Suitable” refers to a main meeting current standards. It is recognized that there will be a variety of standards of rising main present depending upon the age of the building, including dry rising mains in very tall buildings that would currently be required to be fitted with wet rising mains. Dry rising mains in these situations could be considered as potentially negative unless pressure tests can demonstrate that their performance is satisfactory.

Negative

Absence of rising mains in buildings above 18 m

F.10 Lifts for use by firefighters

Note 1 Firefighting lifts are only one aspect relevant to effective fire and rescue service intervention. Annex E gives broader consideration to fire and rescue service intervention and the limitations that can apply to achieving this.

Note 2 There is no requirement for firefighting lifts to be fitted in new buildings below 18 m in height.

Note 3 There can be significant differences in the design and engineering of lifts for use by the fire and rescue service, depending upon when they were installed and the standard applicable at the time. A lift meeting current standards would be seen as a positive factor, whereas it might not be appropriate to attach the same weight to lifts that meet an older standard. BS 8899 gives recommendations for the improvement and maintenance of firefighting provisions in existing lifts. Advice might need to be sought from the fire and rescue service, particularly for very tall buildings, to establish whether what is present is suitable. Where it is not, this is likely to be a notable negative risk factor.

Positive

-

Neutral

Suitable firefighting lift present

Note While firefighting lifts have been a requirement for new buildings above 18 m in height for many years, their role in terms of the effectiveness in intervention by the fire and rescue service is a significant factor.

Negative

Absence of firefighting lift in buildings above 18 m

F.11 Specific fire hazards

Note 1 Consideration would be expected to be given to the mechanisms by which fire can start and spread to involve the external wall construction and cladding (see Clause 5), and any particular ignition sources (e.g. façade lighting) and specific fire hazards present over and above those generally anticipated. See also Annex N.

Note 2 Hazards that can arise in day‑to‑day activities (e.g. the placing of a waste skip close to the building) are matters for ongoing control by the building’s management and would be expected to be addressed in the building’s FRA. Only permanent features of the building that give rise to specific fire hazards are considered here and, even then, a proportionate response might be to remove the hazard, e.g. prevent parking under overhangs, rather than remediate the external walls.

Positive

-

Neutral

Vehicle parking on roadways adjacent to building

Negative

Vehicle parking under overhangs

Open‑sided car parking directly underneath

Positive

-

Neutral

-

Negative

Balconies that have combustible elements, and which are of such a size that it is foreseeable they will be used for significant items of furniture, for holding storage or waste, or for inherently hazardous activities such as holding barbecues

Outbuildings of combustible construction, such as sheds, motorized buggy charging rooms or storage buildings, in close proximity (e.g. <2 m) of the external walls

Permanent refuse storage in close proximity to the external walls.