Guide to tolerances

Guide to tolerances

The Ministry of Business, Innovation and Employment recently published the Guide to tolerances, materials, and workmanship in new residential construction (Guide to tolerances). It is designed to help contractors and their clients identify acceptable building work. This will help all involved to avoid disputes down the line and to save time and money. When disputes do arise, the guide can also help in resolving them.

Resolving disputes

The Guide supports new consumer protection measures that came into force on 1 January 2015 as part of a package of Building Act Reforms. The law change introduced a defect repair period of 12 months from the completion of the building work. During this period any defects identified and notified to the contractor by the client must be fixed in a reasonable time-frame after the client advises them in writing about the defect.

If there is a dispute as to the existence of a defect during the 12 month repair period, it is up to contractors to prove that the work is not defective or that any defects are through no fault of their own, the fault of their subcontractors, or of the products they used.

Under the Building Act 2004, contractors can be held to account for any defective work for up to 10 years from completion. However, if there is a dispute about the existence of a defect after the 12 month repair period has ended, it is up to the client to prove that a defect exists.

Where a defect is suspected, both parties should first refer to the contract documentation, manufacturers’ specifications/installation instructions, consented plans, or relevant New Zealand Standards. Where the dispute cannot be resolved by reference to any of these, the Guide may help with establishing and agreeing– what is, and what is not – a defect.

Agreeing upfront on tolerances

The Guide is also a great tool for both parties to understand and agree on the levels of tolerances, materials, and workmanship that are acceptable for building work. Designers and contractors can sit down with the client before signing a contract and use the guide to help align their expectations of quality with the choice of design, materials, finishes, and the cost of the work. This can help ensure the project is correctly scoped and avoid disappointment and disputes later on.

The Guide is not mandatory and contractors may choose to use their own schedule for acceptable tolerances, materials, and workmanship. In this case they should discuss this with the client and get their agreement in writing before or at the time the contract is signed. Reference to the schedule should preferably be included in the signed contract. If an issue is not covered by a contractor’s schedule, the client may still refer to the Guide.

The Guide covers mainly aesthetic issues in new builds and additions. It does not cover matters about compliance with the Building Code – these are dealt with through other avenues. Information about the Building Code can be found on

The Guide can be downloaded from and is based on current acceptable standards from a cross-section of the construction industry. More information on the new consumer protection measures can be found at

Here’s what the guide says about plasterboard and fibrous plaster.

6.1 Plasterboard, fibrous plaster

No sheet lining material or substrate has a surface that is perfectly flat or totally free from minor imperfections. Although it is impossible to get a perfectly flat or blemish free interior surface, it is possible to reduce the impact and in the end achieve ‘the appearance’ of blemish free flatness from the normal viewing position. Lighting design plays an obvious and significant role in disguising minor (albeit acceptable) surface blemishes.

The normal viewing position for painted non-concrete surfaces is standing at a distance of ≥ 2m (see inspecting surfaces and fixtures).

Click image to enlarge
Plasterboard table

33            Where another form of finish is going to be applied that requires a different level of finish (e.g. a lower level of finish where wallpaper is to be applied), this should be stated in the contract.

34            See NZS 2589:2007-Gypsum Linings-Application and Finishing, and the Association of Wall and Ceiling Industries of Australia and New Zealand (AWCIANZ) Trade Guidelines and Information – Walls and Ceilings (Edition One, 2012).

35            More cracking may occur over time as a result of timber or building movement.

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