Fire Door Standards

The New Zealand Building Code (NZBC) includes requirements for fire doors in the Acceptable Solutions C/AS1 to C/AS6.
The Acceptable Solutions require fire doors to comply with NZS 4520 Fire-resistant door sets (ref. Appendix C C6.1.1).
Fire doors are assigned a fire resistance rating (FRR) from the results of fire testing to AS1530.4.

Fire Resistance Ratings

Fire Resistance Rating (FRR) is the term used to classify fire resistance of primary and secondary building elements, including fire doors, as determined in a standard test for fire resistance. The FRR is made up of three numbers, giving the time in minutes for which each of the criteria Stability, Integrity, and Insulation are satisfied. The Stability criterion is not relevant to fire doors. For example, -/30/30 means:
Stability no requirement/ Integrity 30 minutes/ Insulation 30 minutes.
Stability = Fire Resistance under defined load
Integrity = Resistance to passage of flame or hot gases
Insulation = Temperature rise criterion

Specification of FRR

For buildings designed in compliance with the NZBC Acceptable Solutions C/AS1 to C/AS6, the FRR required for closures in fire and smoke separations is stated in clause 4.16.1.
Self Latching
Under the NZBC definition of a fire door, the door set is required to be self-latching. Fire doors tested to AS1530.4 are required to remain latched for the period of testing corresponding to the integrity rating. Compliance with NZS 4520 further requires that any bolt or function which could render the door leaf non-self-latching must not be fitted. This includes deadbolts, manual flushbolts and the like.
Pair door sets with rebated meeting stiles, astragals or single bevel latches at the meeting stile must be fitted with a sequence selector to ensure self-closure and latching of both leaves.
All fire door leaves must be self-closing (C/AS* Appendix C 6.1.4) and the self-closing device needs to be adjustable to meet the frictional forces requirements. A self-closer mechanism which activates in the event of a fire but does not operate at other times is acceptable (Appendix C 6.1.5).
Frictional Forces
Requirements for the maximum forces required to open any fire or smoke control door on an escape route are set out in C/AS* Appendix C6.1.3. The forces, when applied to the latch stile, must not exceed 67N to release the latch, 133N to set the door in motion, and 67N to open the door to the minimum required width.
Smoke Control
Best door sets are also Smoke Control doors when fitted with appropriate smoke seals.
The FRR for a fire door with smoke control capability is shown as -/x/y sm, so for example
FRR -/60/30 sm indicates a door with 60 minutes Integrity, 30 minutes Insulation, and fitted with smoke seals.
Smoke seals must be fitted at the head and all vertical edges in the gaps between the door leaf and the frame, and between leaves in multi-leaf door sets. Requirements for doors which are Smoke Control only (FRR -/-/- sm) are described on the datasheet for Smoke Control doors.
Sill seals are not required by the Acceptable Solutions, but if otherwise required, must be specified at the time of order.
Sliding fire door sets cannot be supplied as Smoke Control doors, because no suitable smoke seals have been fire tested with these doors.
Doors subdividing escape routes
The requirements for doors subdividing escape routes are set out in C/AS* 3.15 These include requirements for hinging, self-closing, fitting of locking devices, frictional forces, direction of opening, degree and width of opening, vision panels, and hold-open devices. Reference is also made to the requirements for doors on accessible routes in D1/AS1 7.0.
Hold Open Devices
Certain fire doors are required to be fitted with hold-open devices. The locations of such doors are described in C/AS* 3.15.9. The requirements for fire detectors for releasing the hold-open devices are described in C/AS* 3.15.10.
For compliance with the NZBC Acceptable Solutions C/AS2 to C/AS6 (ref. 3.16), fire doors must have a “Fire Door” sign fitted adjacent to the handle or push plate (ref. F8/AS1 5.2 for details). Best Doors Ltd does not supply signs with door sets.

Product Labelling

All fire doors complying with NZS 4520 are supplied with metal labels on which the fire ratings and door set numbers are indelibly marked. In accordance with NZS 4520, Best Doors Limited maintains a register of door sets, and issues an installer’s declaration with each door set. The installer’s declaration is to be completed by the installer and returned, as confirmation of compliance with NZS 4520.
Sample label:


Correct clearances for Bestdoors are generally:
Sills 3 - 10mm
Meeting stiles 3 - 4mm
Other edges 2 - 3mm
Slider edge clearance 10mm back face


NZBC Acceptable Solutions may require specific types of hardware or location of hardware for fire doors, particularly those on escape routes. Compliance with respect to specification and installation is the responsibility of the customer or customer's contractors.
Compliance with NZS 4520 requires that hardware items are tested or otherwise approved for use on the specific fire door construction. For this reason, Best Doors Ltd provides lists of approved hardware for use with its fire door set products.

Supply of Parts

All doors are supplied prehung in frames using Best Doors Ltd stock hinges unless agreed otherwise at the time of order.
Steel frame door sets are supplied with strike plates and closer plates fitted. Preparation for other hardware is carried out according to clients’ instructions. Hardware specifications must be available at the time of ordering doors.
Fixing of hardware to the door leaf may require special fasteners. These will either be supplied or specified according to clients’ instructions.
Edge seals required for fire door sets are fitted in the factory. Jamb smoke seals are supplied loose. Hardware can be prepared for in the factory if this is agreed at the time of order.


Self-closure requirements for fire doors must not be compromised by air pressure conditions within the building or to the exterior. Variable strength closers or high-powered closers are available for use with Best fire doors. Compliance is the responsibility of the customer's contractors or specifiers who determine conditions under which the doors operate.
Additional frame fastening is recommended near the floor wherever skirting is to be fitted.
Detachment of hinged fire doors should be from the frame not the door leaf.
Size modifications to doors must be made in the factory.

Exterior Doors

Doors are intended for use in dry interior conditions unless specified and manufactured as exterior quality.

Exterior Fire Doors must comply with the following conditions:

  • Fully weather exposed doors should be metal-faced on both faces
  • Doors should have paint finish with light colours to minimise heat absorption and subsequent bowing.
  • A steel or aluminium channel is to be factory fitted to the sides and top edge
  • No hardware cutouts in the top edge of doors in exposed exterior situations
  • Hardware cutouts to be fully-sealed
  • Sliders should be in sheltered conditions and hung with track to inside
  • Leaves and frames must be primed or sealed in the factory or else immediately after delivery to site
Exterior BP30 and BB15 doors must comply with the following conditions:
  • No vision panels
  • Leaves and frames must be primed or sealed in the factory or else immediately after delivery to site
  • Doors should have paint finish with light colours to minimise heat absorption
  • No ventilation grilles

Limitations of Use

Refer to the Best Doors Limited Supplier Statement for limitations of use applying to all products including fire door sets.