NEW PART B Design Impacts Peter Chilvers - May 2007

Architectural Practice INTRODUCTION Peter Chilvers FRICS MBEng PRP ARCHITECTS 020 8339 3093 Surrey ~ Smithfield Milton Keynes ~ Manchester Winners Architectural Practice of the Year 2007 PRP recently declared as “The world’s largest residential design practice”

AIMS OF PRESENTATION PREVENT To look at the new factors that stand to influence the design of houses and apartments Note any issues or trends Discuss possible design solutions PREVENT

NEW ADB ~ CORE DESIGN IMPACTS sprinklers Smoke Control Fire Fighting Means of Escape layouts Management issues Inclusive access considerations Relationship with Fire Engineering

ADB 2006 ~ HOW DO WE FIND IT ? OR

HOUSES

HOUSES ~ DIAGRAM 1 ADB1 Dwellinghouse with upper floors below 4.5m Single storey dwellinghouse Escape via stair and egress windows. (Alternatively provide a protected stair) Escape via entrance hall. Inner Rooms provided with egress windows/doors. 4.5m Escape via entrance hall. Inner Rooms provided with egress windows/doors. Dwellinghouse with more than one floor above 4.5m Escape via protected stair. Alternative escape route, or sprinkler coverage.No Inner Rooms. Dwellinghouse with one floor above 4.5m Escape via protected stair. No Inner Rooms allowed. Escape via protected stair. No Inner Rooms. 7.5m Escape via protected stair. Inner Rooms provided with egress windows Escape via protected stair. Inner Rooms provided with egress windows. 4.5m Escape via entrance hall. Inner Rooms provided with egress windows. Escape via entrance hall. Inner Rooms provided with egress windows.

TALLER HOUSES ~ 4 STOREYS AND MORE Protected Stair + AFD + fire separation over 7.5m + ALTERNATIVE ESCAPE OR Protected Stair + AFD SPRINKLER COVERAGE (THROUGHOUT)

OPEN SPATIAL PLANNING IN HOUSES Allowed in two storey housing Not permitted for higher housing, even with sprinkler protection and the fact that enclosure now allows non closing FD ! Recent approval for open plan GF in three storey housing on the following basis: Escape via stairs and GF if tenable FR cut off screen to stairs @ FFL with held open FD Bedroom Bedroom Sprinkler coverage First Floor Escape via egress windows @FFL (if GF untenable) Ground Floor (open plan Kitchen, Lounge / Diner)

“SENSITIVE” HOUSES Smoke Exhaust Can provide: ~ Early warning Can we create a fire safe sensitive house ? Sprinklers (fast response) AFD Smoke Control (Passive or Systems) ? Can provide: ~ Early warning ~ Fire suppression ~ Tenable escape routes ~ Time to escape or “safely stay in place” = Flexibility of Layout

within 45m of all points within the dwellinghouse FIRE FIGHTING ~ HOUSES Access to: within 45m of all points within the dwellinghouse + all access standards 20m max reversing limit open for discussion (Diagram 24 ADB1)

APARTMENTS

APARTMENT LAYOUTS Standard existing flat layouts (as previous ADB) Max 9m travel distance if open plan, or 9m max within protected entrance hall MULTI STOREY APARTMENTS either provide protected stairway, AFD, and alternative exits from levels above or below entrance level (as per existing ADB) OR protected stairway + L2 AFD (all rooms and circulation areas) (subject to any floor level being max 7.5m ± entrance level) protected stairway + AFD (circulation areas, etc) + sprinkler coverage throughout (no height limitation)

OPEN PLAN / SPATIAL APARTMENTS ADB does not recognise (over 9m travel distance) Many duplexes seek open spatial upper level Any solutions? Arup Fire - have Type Approval based on strategic AFD and layout Use of sprinklers, AFD, smoke control and layout being developed Seems to be OK Stateside !

MEANS OF ESCAPE FROM FLATS # 1 ADB2 principles and travel distances remain the same TRAVEL DISTANCE: Single direction = 7.5m max Alternative routes = 30m max (Flat door to entry to Protected Stair or Stair Lobby) SMALL BUILDING CATEGORY: Basics the same, i.e. – max 11m Fl above GL – only 3 storeys above Ground Storey BUT now allows ancillary accommodation at any level if lobby approach BUT prohibits stair connecting to any covered car park (these buildings are allowed modified standards)

MEANS OF ESCAPE FROM FLATS # 2 AOV 7.5m max Vented Corridor or Lobby 4.5m max in unvented Small Buildings OR

MEANS OF ESCAPE FROM FLATS # 3 Protected stairway 7.5m max Unvented corridors STAIR LOBBY Sterile Vented No accommodation to enter directly Unlimited size Options of sizing and layout Central lobby zone – one vent (AOV or shaft) = SPACE GAINS

NATURAL SMOKE VENTING OF COMMON AREAS Venting required to zone (corridor, lobby, stair lobby) immediately proceeding entry to protected stair AOV to single stair OV to multi stair (including any dead end leg) OV to protected stair (AOV where single stair) AOV and OV (to corridors etc) 1.5m² OV (stairs) 1.0m² Or BS12101 test data for Equivalent area air flow

NATURAL VENTING ~ SMOKE SHAFTS ADB2 (Section 2.26) now contains detailed criteria for smoke shafts: Outline = vertical max 4m length offset (@ max 30°) closed base 1.5m² area (min 0.85m l) head 2.5m above top ceiling level discharge @ least 0.5m above roof FR construction and E30S vents AFD activation on fire floor and head 2.5m Smoke Vents @ high level 1.5m²

SMOKE CONTROL VIA MECHANICAL VENTILATION ADB2 Section 2.27 allows for mechanical ventilation to BS EN 12101-6:2005 (which covers ± pressure systems) Travel Distance guidance remains the same This approach is very effective, but does not seem to be overly popular with designers or clients

EXTENDED CORRIDOR SYSTEM # 1 Means of Escape Phase Powered Inlet Air 15 – 20m in any one zone Powered Smoke Exhaust Smoke exhaust ensures reasonably tenable conditions to escape route (much better than ADB base standards) AFD activated – typically 2m³/s exhaust rate – shafts approx. 0.6m² area - system needs maintenance (regular) – sensor selected and reversible fan operation

EXTENDED CORRIDOR SYSTEM # 2 Fire Fighting Phase Powered Smoke Exhaust Powered Smoke Exhaust Fans purge smoke from corridor and staircase (Fire Brigade switch both fans to extract and leave stair doors open) Natural Air Inlet

No travel distance limitations BALCONY APPROACH # 1 BS5588-1: 1990 Worth a revisit – How open? Traditionally single aspect How close can blocks be without creating smoke logging? Can there be some enclosure and still provide equivalent smoke/fire venting ? No travel distance limitations but 60m for fire fighting

BALCONY APPROACH # 2 Open Balconies Enclosed Balconies ? Smoke Curtains / Downstands AO Louvres equiv. H x L H x L Enclosed Balconies ?

SPRINKLERS IN TALLER APARTMENT BLOCKS Apartment blocks with any floor more than 30m above GL must have sprinkler coverage to all dwelling accommodation areas at all levels ADB2, Section 8.14 Installations can be to BS9251:2005 (despite integral 20m ht limit) Also watch for high fire load and 180m² room size limitations Riser duct sizes Space for tanks/pumps Ceiling service zone depths

COMPENSATORY ALLOWANCES NOT FULLY RECOGNISED BY ADB SPRINKLERS COMPENSATORY ALLOWANCES NOT FULLY RECOGNISED BY ADB Increased travel distances – alternative ventilation – openings to atria – decreased fire ratings – open spatial duplexes ! ! ! LEFT TO FIRE ENGINEERING SOLUTIONS

and project specifically VERY TALL BLOCKS Design Holistically and project specifically Issues: “Defend in Place” – Safe to Stay – realistic emergency procedures Evacuation  Fire Fighting – Single Staircases – Lift redundancy Identify and consider all risks (including extreme)

FIRE FIGHTING ~ APARTMENTS Fire Brigade access to within 45m of all points within each dwelling

45m RULE ~ APARTMENTS 45m from fire appliance to all points of all flats ( +10% tolerance ?) Consider fire fighting technique – hose runs from fire appliance into building – along corridors – up stair flights – along landings – along corridors/lobbies on fire floor – into flat Say min 13m within flat Say min 7.5m travel distance + landings = 22m Depending upon storey height and pitch = 5-6m per storey + landing lengths Depending on fire park position outside building ALWAYS needs measuring but highly likely that 3+ stories will now need FIRE MAINS !

(and visible position) FIRE MAINS To be on face of building Fire access to within 18m (and visible position) Wet risers if over 50m height

FIRE FIGHTING SHAFTS ~ APARTMENTS Greater clarity of Fire Fighting Shaft provisions for Apartments ( required if >18m above approach level) Wet Risers if over 50m (was 60m) If sprinklered all accommodation to be within 60m of riser outlet If not sprinklered then 45m max hose run from riser in ordinary protected stairway but 60m if from riser in a FFS 120 mins FR FR as required for building (max 60 mins for flat compartment walls ADB2 Table A1) Flat entrance doors FD30S + all other relevant requirements of BS5588-5:2004

FIRE FIGHTING ~ HYDRANTS New Requirement: applies to new building with a compartment > 280m² Sited > 100m from an existing fire hydrant See ADB2, Section 15.7/8 If building fitted with fire mains Hydrant within 90m of inlet No fire mains Then hydrant within 90m of entrance, and @ 90m centres If no water mains then SWS supply

DISABLED PEOPLE IN FLATS “Inclusive escape “ required in an overall sense by ADB1 and 2 ADB guidance does not require provisions for ordinary apartments ( Because of : - compartmentation – “defend in place” – simultaneous evacuation possible, but not often needed – no history of problems) Specific designs including Wheelchair Disabled Units might generate a need for consideration of Refuge provision (in staircore or lobby) Refuge numbers do not necessarily need to equal disabled population Consider Risk Assessment and management needs Lifetime Homes?

FIRE SAFETY MANAGEMENT ADB – Volume 2 – Section 0.13: “Building Regulations do not impose any requirements on the management of a building. However, in developing an appropriate fire safety design for a building it may be necessary to consider the way in which it will be managed. A design which relies on an unrealistic or unsustainable management regime cannot be considered to have met the requirements of the Regulations. Once the building is in use the management regime should be maintained and any variation in that regime should be the subject of a suitable risk assessment. Failure to take proper management responsibility may result in the prosecution of an employer, building owner or occupier under legislation such as the Regulatory Reform (Fire Safety) Order 2005.” Consultation and Compatibility required across DESIGN  MANAGEMENT  FIRE AND EVACUATION PLANS

Thank You CONCLUSIONS Centred around traditional layouts Better Guidance Easier to use for standard layouts But not ground breaking Centred around traditional layouts Poised to be overtaken by Fire Engineering ? Thank You