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 ?