Last updated: 21 March 2016
This provides information to BCAs who need to process and undertake applications and inspections that rely on a MultiProof.
This provides information to Building Consent Authorities (BCAs) on how to:
- process building consent applications that rely on a MultiProof
- undertake inspections of, and issue code compliance certificates for, projects that obtained a building consent using a MultiProof
- process amendments to building consents that were issued based on a MultiProof, once building work has begun.
What is a MultiProof?
A national multiple-use approval (known as a MultiProof) is a statement by the Ministry of Business, Innovation and Employment (MBIE) that a set of plans and specifications for a building complies with the New Zealand Building Code.
The approved plans and specifications may include:
- design alternatives
- the proposed procedures for inspections.
The MultiProof may be issued subject to:
- a waiver or modification to the Building Code
- one or more conditions.
Under the Building Act 2004, BCAs must accept a MultiProof as evidence of Building Code compliance. The Building Act uses the term ‘national multiple-use approval’ and not ‘MultiProof’.
MultiProofs allow builders who replicate the same or substantially similar buildings several times to benefit from a streamlined building consent process.
This avoids the need for the design to be assessed and re-approved by BCAs each time it is proposed to be built on a different site.
MultiProofs should lead to faster processing times, reduced duplication for volume builders, and lower consenting costs.
A MultiProof is not, and does not replace, a building consent. The holder of a MultiProof must obtain a building consent each time they wish to build the approved design. This enables the BCA to confirm and establish:
- the design, with any permitted variations, is the same as the one in the plans and specifications approved as part of the MultiProof
- the proposed site meets the conditions of the MultiProof conditions
- any site specific features of the design comply with the Building Code
- the inspections required.
However, because the BCA only needs to assess the Building Code compliance of site-specific features excluded from the MultiProof, the statutory timeframe for the BCA to issue a building consent for applications that rely on a MultiProof is 10 working days instead of the usual 20.
Details of issued MultiProofs are posted on a register owned by MBIE. BCAs have password-protected access to the approved plans and specifications in a Shared Workspace. This is to enable the BCA to compare the plans submitted by the building consent applicant to those approved by MBIE.
The online register is updated when a MultiProof is issued, amended, suspended or revoked. BCAs may rely on the register for establishing the validity of approvals.
MultiProofs are valid indefinitely
A MultiProof will be valid indefinitely unless:
- the Building Code changes to the extent that building work properly completed in accordance with the approval will no longer comply
- the approval no longer meets the prescribed eligibility criteria
- or the approval was obtained by fraud, misrepresentation or concealment of the facts.
We will write to the MultiProof holder if the Building Code changes in a way that affects the MultiProof.
We encourage MultiProof holders to review their approved plans and specifications from time to time and consider if they require any amendments. For example to:
- modify the design
- increase the permitted variations
- clarify any issues raised during the construction or consenting process
- update the specification.
Eligibility and the application process
Eligibility provides applicants with information before they apply for MultiProof.
Making an application will give your further information and see what is required for a MultiProof application.
MultiProofs and Restricted Building Work
Restricted building work (RBW) came into effect on 1 March 2012.
MultiProof certificates for houses and small to medium-sized apartment buildings, issued prior to 1 March 2012 will not contain any information about RBW or LBPs, while those issued after 1 March 2012 will list the LBPs involved in the design of any RBW.
The effects of RBW on MultiProofs, for houses and small to medium-sized apartment buildings are summarised below:
- For MultiProof applications that were received before 1 March 2012, the applicant did not need to supply MBIE with Memoranda (Certificates of design work).
- For MultiProof applications received on or after 1 March 2012, the applicant will need to provide these memoranda to MBIE as part of their MultiProof application. MBIE will check that the design RBW requirements have been met, and will hold the memoranda with the rest of the application documentation. The MultiProof certificate will list the Design LBPs who were involved in the design of the RBW for that approved design.
- For applications submitted both before and after 1 March 2012, each time a building consent application that relies on a MultiProof is lodged, the applicant will need to supply the BCA with memoranda for any RBW related to the site-specific design.
- The applicant will also need to supply the BCA with a list of the trade LBPs who will carry out or supervise the construction of the RBW (as per a normal building consent application).
- Upon completion of construction, and as part of an application for a code compliance certificate, the applicant will also need to provide a Memorandum (Record of building work) from each of the trade LBPs involved in the construction of any restricted building work (as per a normal code compliance certificate process).
Restricted Building Work can give you further insight into what is required.
Processing a building consent application that relies on a MultiProof
When a BCA receives a building consent application that relies on a MultiProof, it should do the following:
- check the application is complete, based on the list provided on the previous page of this document
- ensure the application is within the terms of the MultiProof and that the approval is current
- assess the Building Code compliance of any building features not covered by the MultiProof (for example, site-specific features, such as drainage)
- check that the Memoranda (Certificates of design work) for the site-specific RBW include all the necessary information
- ensure that the proposed site meets the conditions of the MultiProof (such as wind or climate zone limitations)
- ensure any other approval conditions are met
- issue the building consent within 10 working days (provided all the above requirements have been met)
- advise the applicant, in the building consent, of inspection requirements and any documentation that must be supplied before the code compliance certificate will be issued, such as an energy work certificate and Memoranda (Records of Building Work) from the trade LBPs involved in the construction of RBW.
The BCA does not need to:
- establish the Building Code compliance of the design covered by the MultiProof
- undertake extensive comparison between the approved plans and specifications provided by the applicant and those published independently on MBIE’s public register.
MultiProof only applies to plans and specifications including any approved design alternatives MBIE has specifically approved and handed (mirrored) versions of the same design.
As part of applying for a MultiProof, applicants are encouraged to include any alternatives they may wish to use.
Examples of design alternatives include, but are not limited to:
- material alternatives
- different cladding types
- changes to window and door locations or configurations
- variations to the floor plan (such as adding a garage or a conservatory)
- handed (mirrored) floor plans
- different bathroom and kitchen layouts
- options for heating or hot water
- changes in roof pitch (such as for roof pitches between x and y degrees)
- building dimensions (for example, sheds using a standard roof design, or to allow a living area to be increased)
- options for different wind and earthquake zones (such as bracing up to a certain level)
- options for different exposure zones
- foundation options for different soil capacity and site levels (for example, either with no foundations included or with a foundation option for good ground)
- options for different climate zones (such as differing insulation levels)
- options for add-ons such as garages, decks and conservatories.
A MultiProof can also allow for a more flexible building design involving building modules and connections between them.
These alternatives are listed as permitted variations and conditions on the MultiProof certificate.
Where a range of alternatives are proposed a design and options summary may also be referenced on the certificate.
Parameter based variations
A MultiProof can also include parameter based variations.
Parameters are a set of design rules that any changes to the design would comply with. Parameter based applications are suited to low risk buildings and those that use standardised construction details or building systems.
The approval documents for a MultiProof with parameter based variations will include:
- drawings for a reference building or number of reference buildings along with a series of standard construction details
- a set of design parameters
- a compliance assessment report which states how compliance will be achieved
- a comprehensive specification which covers the full range of selections
- an options selection schedule with references to the drawings and sections of the specification.
The BCA processing requirements for a building consent that relies on a MultiProof with parameter based variations will differ. In addition to the process outline above the BCA will be required to:
- check that the building design is within the defined parameters
- check that the means of compliance is the same as the approved means of compliance.
- in some cases additional checking may be required for example to check the bracing calculations or locations.
Departures from MultiProof
When applying for building consent
The building consent applicant can only rely on a MultiProof if they intend to build the design and any approved alternatives.
If the applicant has made design changes that have not been approved as part of the MultiProof, the BCA will need to assess the whole design for Building Code compliance and the normal processing period of 20 working days will apply.
However, we encourage BCAs to take a reasonable approach to this:
- If the changes do not affect Building Code compliance (for example, the applicant has substituted a bath for a shower), the BCA may still be able to apply the MultiProof as a means of compliance for the rest of the design.
- If the changes do affect Building Code compliance, the BCA may still be able to use the MultiProof as a means of compliance for other parts of the design.
Once the building consent has been issued, work proceeds as it would for any other project.
Amendments after a building consent has been issued
Any amendments or variations the building consent holder wants to make to the consented plans will need to be approved by the BCA.
The process for seeking an amendment to the building consent should be straightforward if the change is one of the permitted variations included in the MultiProof.
If the amendment is not one of the permitted variations, and there is time, the MultiProof holder can apply for an amendment to the MultiProof. The building consent holder will then need to submit an application for an amendment to the building consent based on the amended MultiProof.
The BCA can also grant the amendment if it considers that the building work, if carried out in accordance with the proposed changes to the plans and specifications, will comply with the Building Code.
The BCA has no grounds to refuse an application for an amendment to a building consent because a MultiProof does not apply.
If the changes are not permitted by the MultiProof the BCA must make its own assessment of the compliance of the plans and specifications with the requirements of the Building Code.
Responsibilities of BCAs for MultiProofs
In simple terms, the BCA is not responsible for:
- checking the Building Code compliance of those parts of the design approved by MBIE.
The BCA is responsible for:
- being reasonably satisfied that the building consent application complies with the relevant MultiProof (including through the statement supplied by the applicant)
- ensuring conditions of the MultiProof are met
- assessing the Building Code compliance of any site-specific features that have not been approved by MBIE (for example, foundations or site drainage)
- ensuring that the building work is carried out in accordance with the building consent
- assessing and approving any amendments sought by the applicant once building work has begun
- issuing a code compliance certificate, once satisfied compliance has been achieved
- informing MBIE of any non-compliances contained in the MultiProof
- keeping all necessary records and information.
Disputes between the BCA and applicant
If there is a dispute with the applicant at the building consent stage or after work has begun, for clarification the BCA should contact MBIE’s MultiProof team.
Accessing plans and specifications
Approved MultiProof documents are housed in an online facility called a Shared Workspace. This is a secure website that allows Building Consent Authorities to view the approved plans and specifications.
The MultiProof register gives you further information on how to access the online Shared Workspace.
Building consent applications for more than one building
If the applicant submits a building consent application for two buildings, and only one is covered by the MultiProof, the BCA should rely on the approval as far as possible and assess the Building Code compliance of the other building's in the normal way.
Applicants who want to benefit from the 10-day processing timeframe may wish to present the building consent application in separate parts.
Effects of Building Code changes on MultiProofs
If the Building Code changes in a way that materially affects compliance, or if a product used in an approval becomes banned, MBIE has the authority to suspend or revoke an approval.
An amendment to an Acceptable Solution or Verification Method does not invalidate a MultiProof approval. Designs are assessed against the Building Code itself, not the acceptable solutions or related standards.
For example, a change to B1/AS1 (effective on a specific date) or the introduction of a revised standard will not affect designs that were MultiProof approved before the effective dates. The BCA is required, under Section 19(1)(ca) of the Building Act, to accept the MultiProof approval as evidence of Building Code compliance, and the approval remains valid unless MBIE revokes the approval.
The status of approvals can be obtained from the MultiProof register.