Getting in and getting out safely

By - , Build 158

The Building Code has strict requirements for providing access and escape routes for fire safety. Emergency staff need to be able to enter a building, and many non-residential buildings need at least one accessible access route for use by disabled persons.

THE NEW ZEALAND BUILDING CODE (NZBC) requires buildings to be constructed so they are safe to enter and move about in. They must also be safe in the event of fire when people are escaping from the building and when the Fire Service and emergency services need to access the building.

NZBC clause D1 Access routes and Acceptable Solution D1/AS describe requirements for access routes.

NZBC clause C Protection from fire section 4.2 and Acceptable Solutions C/AS1–C/AS7 describe requirements for ensuring safe escape routes.

Many routes into and within buildings are also escape routes and therefore will need to satisfy requirements for both access and escape.

Accessible routes

All access routes need to meet minimum requirements for size, slope, slip resistance, design of stair treads and risers. In addition, some buildings, housing excepted, also need to have at least one access route that is an accessible route.

This is to ensure that people with disabilities can enter and use these buildings. An accessible route has:

  • additional requirements for signage
  • space to accommodate wheelchairs
  • lifts for some buildings with upper floors
  • door hardware for ease of use.

An accessible route excludes some types of stair, for example, spiral and open treads.

Escape routes

Escape routes provide a continuous unobstructed route starting from any occupied space in a building to a final exit to enable occupants to reach a safe place. This safe place may be outside the building, and people can then safely disperse in the event of fire.

Escape routes may be divided into open paths, smoke lobbies and safe paths – horizontal or vertical.

An open path can be anywhere within the occupied spaces in the building. It will either provide an escape route directly to outside or lead to a smoke lobby or safe path that provides a route to a safe place.

Smoke lobbies and safe paths are part of an exitway.

A safe path is constructed to protect occupants from the effects of fire. Examples include stair enclosures in multi-level buildings and some corridors when required to be built using fire-rated construction.

Occupants escape by travelling along an escape route, starting in the open path, continuing to a safe path and then leaving the building to reach a safe place.

Is an access route an escape route?

All escape routes are also access routes. However, not all access routes need be escape routes if enough alternative escape routes from occupied parts of the building are provided.

Table 1 summarises requirements for some common features applying to access routes and escape routes. This table does not apply to Risk Group SI buildings. Refer to Acceptable Solution C/AS3 for buildings such as institutions, hospitals and rest homes.

Necessary signage

Signs must be provided so that accessible routes and facilities provided for people with disabilities can be identified. Similarly, all escape routes, fire doors and smoke control doors must also have signs. Signs must comply with NZBC clause F8 Signs.

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Width and height

Access routes and escape routes have minimum requirements for height and width depending on whether they are also required to be an exitway or an accessible route. Greater widths may be needed depending on the number of people required to use them.

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Allowable projections

Minor projections are permitted to encroach on the minimum required clear width of access routes and escape routes with the permitted amount of projection dependent on its height above floor level. Handrails may project no more than 100 mm into the required minimum clear width.

Acceptable Solutions

Refer to D1/AS and C/AS1–C/AS7 for the Acceptable Solution requirements for access routes and escape routes.

Table 1
REQUIREMENTS FOR COMMON ACCESS ROUTE AND ESCAPE ROUTE FEATURES
FEATUREACCESS ROUTES  ESCAPE ROUTES  
 ACCESSIBLE ROUTENOT ACCESSIBLE ROUTEEXITWAY (INCLUDES SMOKE LOBBIES AND SAFE PATHS) OPEN PATH 
   ACCESSIBLE ROUTENOT ACCESSIBLE ROUTEACCESSIBLE ROUTENOT ACCESSIBLE ROUTE
MINIMUM ROUTE WIDTH (RAMPS AND HORIZONTAL, E.G. CORRIDOR) 1,200 mm - 1,200 mm 1,000 mm 1,200 mm 850 mm (or 700 mm where <50 occupants)
MINIMUM ROUTE WIDTH (VERTICAL, E.G. STAIRWAY) 900 mm between handrails 900 mm between handrails for common stairs 1,100 mm 1,000 mm 1,100 mm 1,000 mm (or 850 mm where <50 occupants)
MINIMUM DOOR OPENING CLEAR WIDTH 760 mm - 1,075 mm (within horizontal safe path)

975 mm (within vertical safe path)
875 mm 760 mm 600 mm
MINIMUM ROUTE CLEAR HEIGHT 2,100 mm 2,100 mm (lesser height applies to crawl spaces and landing, stairway or corridor less than 2 m long) 2,100 mm 2,100 mm 2,100 mm 2,100 mm
MINIMUM DOOR OPENING HEIGHT - - 1,955 mm 1,955 mm 1,955 mm 1,955 mm
MINIMUM SLIP RESISTANCE ON LEVEL ACCESS Yes, level surfaces, ramps and stairs Level surfaces where used by the public plus all ramps and stairs Yes, level surfaces, ramps and stairs Level surfaces where used by the public plus all ramps and stairs Yes, level surfaces, ramps and stairs Level surfaces where used by the public plus all ramps and stairs
SIGNAGE NZBC F8 Not required NZBC F8 NZBC F8 NZBC F8 NZBC F8
HANDRAILS IN STAIRWAYS Required Depends on width, number of risers and occupancy type Required Required Required Required

Note: This table does not apply to Risk Group SI buildings.

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