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Peter Chilvers - May 2007
NEW PART B
INTRODUCTION
Peter Chilvers FRICS MBEng PRP ARCHITECTS 020 8339 3093 Surrey ~ Smithfield
Milton Keynes ~ Manchester Winners
Architectural Practiceof the Year 2007
PRP recently declared as“The world’s largest residential design practice”
AIMS OF PRESENTATION
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
Inclusive access considerations
sprinklers
Fire Fighting
Relationship withFire Engineering
Management issues
Smoke Control
Means of Escape layouts
ADB 2006 ~ HOW DO WE FIND IT ?
OR
HOUSES ~ DIAGRAM 1 ADB1
Escape via entrance hall.Inner Rooms provided
with egress windows/doors.
Escape via entrance hall.Inner Rooms provided
with egress windows/doors.
Escape via stair and egress windows.
(Alternatively provide aprotected stair)
Escape via entrancehall. Inner Rooms
provided with egress windows.
Escape via protected stair. Inner Rooms
provided with egresswindows
Escape via protected stair. No Inner Rooms
allowed.
4.5m
4.5m
Escape via entrance hall. Inner Rooms provided with
egress windows.
Escape via protected stair. Inner Rooms provided with
egress windows.
Escape via protected stair. No Inner Rooms.
Escape via protected stair.Alternative escape route,
or sprinkler coverage.No Inner Rooms.
7.5m
Single storey dwellinghouse
Dwellinghouse with upper floors below 4.5m
Dwellinghouse with one floor above 4.5m
Dwellinghouse with more than one floor above 4.5m
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:
Ground Floor(open plan Kitchen, Lounge / Diner)
Bedroom
Bedroom
Escape via stairs and GF
if tenable
Escape via egress windows
@FFL(if GF untenable)
First Floor
FR cut off screento stairs @ FFL
with held open FD
“SENSITIVE” HOUSES
Can we create a fire safe sensitive house ?
Sprinklers (fast response)
AFD
Smoke Control (Passive or Systems) ?
Smoke Exhaust
Can provide:
~ Early warning
~ Fire suppression
~ Tenable escape routes
~ Time to escape or “safely stay in place”
= Flexibility of Layout
FIRE FIGHTING ~ HOUSES
Access to:
• within 45m of all points within the dwellinghouse
20m max reversing limitopen for discussion(Diagram 24 ADB1)
+ all access standards
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 APARTMENTSeither
• 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 OKStateside !
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 Stairor Stair Lobby)
SMALL BUILDING CATEGORY:
Basics the same, i.e. – max 11m Fl above GL – only 3 storeys above Ground StoreyBUT 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
7.5m max
AOV
Vented Corridor or
Lobby
OR4.5m max
in unventedSmall Buildings
MEANS OF ESCAPE FROM FLATS # 3
7.5m max
Unventedcorridors
Protectedstairway
STAIR LOBBY• Sterile• Vented • No accommodation to enter directly • Unlimited size
Options of sizing and layoutCentral 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 forEquivalent area air flow
NATURAL VENTING ~ SMOKE SHAFTS
ADB2 (Section 2.26) now containsdetailed 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
0.5m
1.5m²
Smoke Vents @ high level
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
15 – 20min any one zone
Powered Inlet AirPowered
Smoke Exhaust
Means of Escape Phase
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
Powered Smoke ExhaustPowered
Smoke Exhaust
Fire Fighting Phase
Fans purge smoke from corridor and staircase(Fire Brigade switch both fans to extract and leave stair doors open)
Natural Air Inlet
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 enclosureand still provide equivalentsmoke/fire venting ?
No travel distance limitations
but 60m for fire fighting
BALCONY APPROACH # 2
Enclosed Balconies ?
Open Balconies
H x LAO Louvresequiv. H x L
Smoke Curtains / Downstands
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 toBS9251:2005
(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
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
VERY TALL BLOCKS
Issues: “Defend in Place” – Safe to Stay – realistic emergency proceduresEvacuation Fire Fighting – Single Staircases – Lift redundancyIdentify and consider all risks (including extreme)
Design Holisticallyand project specifically
FIRE FIGHTING ~ APARTMENTS
Fire Brigade access to within
45m of all points within each dwelling
45m RULE ~ APARTMENTS
45m from fire appliance to allpoints 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 flatSay 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 !
FIRE MAINS
To be on face of building
Fire access to within18m
(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 FRFR as required for building(max 60 mins for flat compartment walls ADB2 Table A1)Flat entrance doors FD30S
+ all other relevant requirements ofBS5588-5:2004
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 mainsHydrant within 90m of inlet
No fire mainsThen hydrant within 90m of
entrance, and @ 90m centres
If no water mainsthen 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
CONCLUSIONS
Better Guidance
Easier to use for standard layouts
But not ground breaking
Thank You
Centred around traditional layouts
Poised to beovertaken by
Fire Engineering ?
Recommended