In the interests of affordability.efficiency and general economics the move to prefabricate buildings has gained renewed attention.
The issue of how prefabrication deals with compliance requirements has arisen.
This paper attempts to clarify the framework and the requirements of the building code and how the building act pertains to this manufacture off site.
The Building Act Framework;
The building act 2004 states in s17 that all 'building work' must comply with the building code to the extent required by the act. S44 states that an owner must obtain a building consent prior to the commencement of 'building work'.
Building work is a defined term in the building act and the key to the prefabrication argument.
Building work is defined as; ((a) means work--(i)for, or in connection with, the construction, alteration, demolition, or removal of a building; and
(ii)on an allotment that is likely to affect the extent to which an existing building on that allotment complies with the building code; and
(b)includes sitework; and
(c)includes design work (relating to building work) that is design work of a kind declared by the Governor-General by Order in Council to be restricted building work for the purposes of this Act; and
(d)in Part 4, and the definition in this section of supervise, also includes design work (relating to building work) of a kind declared by the Governor-General by Order in Council to be building work for the purposes of Part 4
We note that there is an "and"after (a) (i) and therefore there are two limbs to the definition; 1. it is work to a building AND 2. it is on an allotment with implications for compliance with the building code. If it doesn't satisfy these 2 limbs it is not building work
Building is also defined in s8; (emphasis added)
Building: what it means and includes (1) In this Act, unless the context otherwise requires, building— (a)means a temporary or permanent movable or immovable structure (including a structure intended for occupation by people, animals, machinery, or chattels); and (b) includes— (i) a mechanical, electrical, or other system; and (ii) any means of restricting or preventing access to a residential pool; and (iii)a vehicle or motor vehicle (including a vehicle or motor vehicle as defined in section 2(1) of the Land Transport Act 1998) that is immovable and is occupied by people on a permanent or long-term basis; and (iv) a mast pole or a telecommunication aerial that is on, or forms part of, a building and that is more than 7 m in height above the point of its attachment or base support (except a dish aerial that is less than 2 m wide); and (c) includes any 2 or more buildings that, on completion of building work, are intended to be managed as one building with a common use and a common set of ownership arrangements; and (d) includes the non-moving parts of a cable car attached to or servicing a building; and (e) after 30 March 2008, includes the moving parts of a cable car attached to or servicing a building. (2) Subsection (1)(b)(i) only applies if— (a) the mechanical, electrical, or other system is attached to the structure referred to in subsection (1)(a); and (b) the system— (i) is required by the building code; or (ii) if installed, is required to comply with the building code. (3) Subsection (1)(c) only applies in relation to— (a)subpart 2 of Part 2; and (b) a building consent; and (c) a code compliance certificate; and (d) a compliance schedule. (4) This section is subject to section 9.
What constitutes a building is a controversial topic at present with much debate around the Tiny House movement that is based on the inclusion of vehicles only if they are immovable and permanently occupied.
The key is what is meant by "structure" which is not defined in the building act. The RMA defines structure as; structure means any building, equipment, device, or other facility made by people and which is fixed to land; and includes any raft. (emphasis added)
fixed to land would mean that a construction didn't become a building until "fixed to land"
(Note; This issue is not discussed here except to say that the issue could be moot point if the tiny houses are prefabricated off site. The issue is only in respect to the work dome on site that needs building consent and knowing the prefabricated unit is fit for purpose and safe and sanitary.)
Recent determination in relation to allegations of building work without consent have implied that while the building work on site requires a building consent work done off site is not the responsibility of the owner. (refer determination 2019-047)
Prefabrication of products components and assemblies while intended to be part of a building are not building work because they are not on an allotment where code compliance is required in respect to the work (or may not be if manufactured off site)
Prefabrication of a whole house off site is the logical conclusion of manufacturing a building off site.
The tap and roof truss does not need a consent and neither does the prefabricated dwelling. This is because it is not building work till it arrives on site and then only the work to the building needs a consent (foundations and waste connection and services etc)
Whether the building complies with the building code is thus more a question of what standard is the building constructed to and will the completed building meet the purposes of the building act to provide a safe and healthy dwelling if a residential unit.
The answer to this must be the same for the tap and truss manufacturer as for the pre=fabricator.
It could be sad that prefabrication results in a building but building work was not required to achieve it.
How is compliance to be verified if a building consent is not involved?
the situation is no different from the manufacturer of a widget. tap or truss or other assembly. A building consent is not required for manufacture of products or assembly's and a prefabricated module is no different, The scope is limited by practical size and ability to transport which also means a structure of sufficient strength and regidity to withstand movement stresses. Likely more than will be experienced on site when relocated.
The answer is in s14G of the building Act; Responsibilities of product manufacturer or supplier(1) In subsection (2), product manufacturer or supplier means a person who manufactures or supplies a building product and who states that the product will, if installed in accordance with the technical data, plans, specifications, and advice prescribed by the manufacturer, comply with the relevant provisions of the building code.
(2) A product manufacturer or supplier is responsible for ensuring that the product will, if installed in accordance with the technical data, plans, specifications, and advice prescribed by the manufacturer, comply with the relevant provisions of the building code.
The question is how the manufacture demonstrates this compliance??
A manufacturers product statement could cover the issue or some form of independent assessment of compliance
Another option is a Code of Practice that allows a manufacturer to comply with and give others confidence in the satisfactory performance and amenity in a prefabricated building.
The changes are yet to be detailed. While it is encouraging that prefabricated buildings are being considered low risk activity including a prefabricated building under schedule 1 still presumes that a building consent was needed in the first place.
