All building services must maintain the clearances between adjacent components specified in in NZS 4219:2009 Table 15 (unless specified elsewhere). Note that suspended ceiling hangers and braces are considered to be restrained components for the purposes of this table.

Condition being considered

Minimum clearance



Unrestrained component to unrestrained component

250 mm

50 mm

Unrestrained component to restrained component

150 mm

50 mm

Restrained component to restrained component

50 mm

50 mm

Penetration through structure (such as walls and floors)

50 mm

50 mm

(From NZS 4219:2009, provided by Standards New Zealand under licence 001149)

Piping, ducting and cable tray systems that do not need to be restrained should be installed with a clearance of 150 mm from hangers/braces used to suspend ceilings systems or other components.

Equipment that is not supported by a suspended ceiling should have a clearance of at least 25 mm all round to allow independent movement between the component and ceiling.

Suspended ceiling hangers and braces should not be used to support electrical cables or fixtures.