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As nearly as is reasonably practicable (ANARP)

Last updated: 1 February 2016

If you are changing the use of a building, or altering a building, you need to consider a requirement for buildings to be brought to comply 'as nearly as is reasonably practicable' (ANARP) with the provisions of the Building Code.

Building Act requirement

This information was confirmed as current in February 2016. It originally appeared in Codewords newsletters prior to January 2014.

The Building Act 2004 (sections 112 and 115) has a requirement for buildings to be brought to comply ‘as nearly as is reasonably practicable' (ANARP) with the provisions of the Building Code, in the following circumstances:

  • where a change of use of a building is intended, which involves the incorporation in the building of one or more household units where household units did not exist before, then the building in its new use must comply in all respects
  • where alterations to, or a change of use of, existing buildings are intended, then the means of escape from fire and access and facilities for people with disabilities must comply.

This ratchet mechanism is a useful means by which the nation's building stock can be upgraded for safety, health and access by people with disabilities, whenever the owner is doing other building work. It is therefore important that the evaluation to decide the extent of the upgrade is effective, whenever the conditions exist for section 112 or 115 to be invoked.

While the wording between the previous and current Act has changed slightly, the intent and detail remains, so the experience and knowledge gained under the 1991 Act can be applied.

Sacrifices and benefits of ANARP

The term 'reasonably practicable' is not a new legal concept. It holds the same meaning as the phrase 'as low as reasonably practicable', which is a concept used in evaluating safety systems. Therefore it is possible to use methodologies from safety system evaluations in the building sector, particularly in more complex situations.

Identifying and evaluating as 'nearly as reasonably practicable' (ANARP) is not an easy task. This is why building consent applicants do not always provide a clear analysis on which a decision can be made. A proper analysis is based on an evaluation of the sacrifices and benefits.

The sacrifices are the tangible and intangible costs that the owner will meet in achieving certain benefits. This can include obvious things such as the direct cost of carrying out upgrades - for example, installing a lift or sprinkler system - but can also include factors such as business interruption and loss of amenity values. These sacrifices are generally upfront, and can be ongoing.

The benefits are meeting the Building Code objectives under consideration, such as fire safety and access. Benefits can be expressed and evaluated in terms of reduced fire safety risk or the number of disabled users that will now have access to the building.

However, it is more common to evaluate benefits by showing how they satisfy the provisions of the relevant Acceptable Solutions and Verification Methods.

The following graphical representation is a useful way to consider the analysis.

The graph illustrates a number of points. Firstly it shows an increasing return Fig.1: Sacrifices and benefits

The graph illustrates a number of points. Firstly it shows an increasing return (benefit) from an increasing level of sacrifice. Secondly, it shows that a point is reached where a significant increase in the sacrifice is made for a comparatively small gain in the resulting benefits. It can be argued that this defines the point 'as near as is reasonably practicable' (ANARP).

Preparing a good application

Some applicants present only the sacrifice involved in achieving compliance, thereby creating the impression that the sacrifice is too great. They often ignore other possible options as well.

Good applications show:

  • a range of options showing the various combinations of sacrifice and benefits that are possible within the design
  • a clear articulation of the sacrifices and benefits, with justification of the data used, the assumptions made and (if possible) a sensitivity analysis. 

Related determinations

Some determinations which relate to the 'as nearly as is reasonably practicable' (ANARP) argument are 2006/77 and 2006/78. These determinations cover:

  • multi-tenanted buildings
  • the role of Acceptable Solutions in evaluating benefits
  • the possibility of progressive upgrading as other building work takes place.

Determinations explains our legally binding rulings and includes a register.  

This information is published by the Ministry of Business, Innovation and Employment’s Chief Executive. It is a general guide only and, if used, does not relieve any person of the obligation to consider any matter to which the information relates according to the circumstances of the particular case. Expert advice may be required in specific circumstances. Where this information relates to assisting people: