1. NEW PART B
Design Impacts
Peter Chilvers - May 2007

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

3. 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

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

5. ADB 2006 ~ HOW DO WE FIND IT ? OR

6. HOUSES

7. 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.

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

9. 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 FFL
with held open FD
Bedroom
Bedroom
Sprinkler coverage
First Floor
Escape via egress
(if GF untenable)
Ground Floor
(open plan Kitchen, Lounge / Diner)

10. “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

11. 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)

12. APARTMENTS

13. 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)

14. 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 !

15. 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)

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

17. 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

18. 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

19. 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
least 0.5m above roof
FR construction and E30S vents
AFD activation on fire floor and head
2.5m
Smoke high level
1.5m²

20. SMOKE CONTROL VIA MECHANICAL VENTILATION
ADB2 Section 2.27 allows for mechanical ventilation to BS EN :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

21. 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

22. 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

23. 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

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

25. 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

26. 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

27. 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)

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

29. 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 !

30. (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

31. 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

32. 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, 90m centres
If no water mains
then SWS supply

33. 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?

34. 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

35. 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