Tolerances tables

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Tolerances tables

In Build 155 Within tolerance, we outlined some of the allowable tolerances to work within for a quality result. Here, we’ve summarised that information into convenient tables.

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Site preparation

This article has now been updated and replaced by Tolerances tables in Build 184.

A Construction tolerance is an allowable variation in something that can be measured. These may be:

the permitted variation from a given dimension or quantity
the range of variation permitted in maintaining a specified dimension
a permitted variation from location or alignment.

While these tolerances are a permitted deviation from perfect, the aim is always to be accurate when constructing and finishing a building. Taking everything to the outer tolerance limit may make achieving quality difficult for following trades.

**Table 1**
SITUATION	ACCURATE TO WITHIN:	REFERENCE
BUILDING SET-OUT
Location on site	15 mm of the specified location on a site plan	NZS 3604
Building footprint	1/200th of the length, up to maximum of ±5 mm of the specified dimensions	NZS 3604
Location of walls within building	1/200th of the length, up to maximum of ±5 mm of the specified dimensions	NZS 3604
Deviation from vertical	15 mm per 2-storey height (5 mm per 2.4 m)	NZS 3604
CONCRETE SLAB ON GROUND
Deviation from prescribed finished floor level	10 mm in any one room or space	NZS 3109
Surface level	±3 mm in any 3 m of length	NZS 3109

**Table 2**
ELEMENT	SITUATION	ACCURATE TO WITHIN:	REFERENCE
SUSPENDED FLOORS
Piles	Concrete piles verticality	15 mm per m of height	BRANZ
	Timber piles verticality	10 mm of vertical in the first m above ground and within 20 mm of vertical over their total length	BRANZ
	Driven timber piles	15 mm of vertical for every m of length	NZS 3604
	Bearers and joists to horizontal	5 mm for every 10 m; 10 mm in total for lengths over 10 m	NZS 3604
Framing	Bearers and joists straightness	±5 mm per 1 m	BRANZ
	Bearers and joist parallelity	±5 mm per 3 m	BRANZ
	Floor plane levelness	A slope of no more than 1:200	MBIE
	Suspended floor deflection	1/360th of span maximum	BRANZ

References to MBIE in the tables refer to the MBIE Guide to tolerances, materials and workmanship in new residential construction 2015, this is available from www.building.govt.nz.

**Table 3**
SITUATION	ACCURATE TO WITHIN:	REFERENCE
TIMBER QUALITY
Bow	15 mm in a 2.4 m length of 50 mm thick framing (35 mm for a 3.6 m long member)	NZS 3631
Crook	10 mm in a 2.4 m length of 100 mm wide framing (15 mm for a 3.6 m long member)	NZS 3631
Twist	5 mm per 100 mm of width in a 2.4 m length of 50 thick framing (10 mm for a 3.6 m long member)	NZS 3631
TIMBER ROOF FRAMING
Vertical elements	Straight to within ±5 mm for every 2.4 m rise in height	NZS 3604
Horizontal elements	Straight to within ±5 mm in lengths up to 10 m; 10 mm in total for lengths over 10 m	NZS 3604
TIMBER WALL FRAMING
Deviation from:
position on plan	15 mm maximum	NZS 3604
line in plan	5 mm for lengths up to 10 m; 10 mm in total for lengths over 10 m	NZS 3604
horizontal	5 mm for lengths up to 10 m; 10 mm in total for lengths over 10 m	NZS 3604
a flat plane across face of wall	±6 mm for every 3 m in any direction	NZS 3604
Inter-storey relative displacement of loadbearing walls	5 mm for vertical alignment	NZS 3604
Permitted bow in studs at corners	2 mm in any 2.4 m length	NZS 3604
Permitted bow in studs	6 mm gradual bow permitted	NZS 3604
Verticality of frames	±5 mm for every 2.4 m rise in height	NZS 3604
Alignment of wall framing	1.5 mm for every 1.3 m or 6 mm over 3 m using horizontal straight edge	NZS 3604
FLOORING
Finished floor	Slope no more than 1:200	MBIE
	5 mm maximum deviation in any 10 m length; 10 mm in total for lengths over 10 m	BRANZ
	Level to within ±5 mm within a single room or space	BRANZ
Flooring – individual sheets or boards	Flat and straight to within ±6 mm for every 3 m of length	BRANZ

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Tolerances tables

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