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 Building Code.

To be eligible you must have the intention and the ability to build an approved design at least 10 times over two years.

MultiProof speeds up the consenting process. It does not give the right to carry out building work that requires a building consent. You still need to apply for consent each time you want to build.

How MultiProof works

MultiProof establishes that a design complies with NZ Building Code.

When your building consent application includes a MultiProof the BCA must grant or refuse it within 10 working days instead of the usual 20.

The Building Consent Authority (BCA) confirms and establishes:

• the design, with any permitted variations, is the same as the design approved in the MultiProof
• the proposed site meets the conditions of the MultiProof
• the site-specific features of the design comply with the Building Code
• the inspections required.

There are certain documents, plans and specifications you will need to submit when you make your MultiProof application.

Download the MultiProof application form, together with the Compliance assessment report. You can have a look at Compliance assessment report example to see what type of information we expect from you.

Refer to making an application to find more information about the MultiProof application process, as well as other documents, plans and evidence you will need to provide.

Supporting Documents

Your MultiProof application documentation may differ from how you would usually put together a site specific design.

You should consider how to document your design in order to:

• provide the level of flexibility you require
• enable the design to be efficiently assessed
• make it easier for your clients and BCAs to understand the alternatives.

Building Plans and Specifications

The drawings and specifications you submit as part of your MultiProof application should:

• describe the intended construction of the building
• demonstrate how compliance with the relevant performance requirements of the Building Code is achieved
• provide sufficient dimensions, detail and information to enable the builder to construct the building as intended
• state if all or part of the building is to be prefabricated
• define all design alternatives.

The specifications should complement the drawings. This means information on the drawings should not be repeated in the specifications, and vice versa.

A brief description on the drawings should be backed up in the specifications by:

• a full description
• statements relating to relevant reference documents
• technical trade literature.

You can also include the proposed inspection procedures and request they be approved as part of the MultiProof.

What not to include:

You should not include the following in your application:

• construction outside the scope of the application
• contractual information
• site specific information
• references to ‘or equal/other approved equivalent’
• general references to clauses within an AS/NZS standard or Acceptable Solution (the actual clause should be included)
• details of work that is not required to be assessed for Building Code compliance (such as shop drawings or internal joinery details).

Components, Materials and Products

Your drawings and specifications should include details about components, materials and products.

This includes any product technical statements that are available from manufacturers or suppliers for critical building products or systems. Including this information tells us what items are to be used and how they comply with the relevant clauses of the Building Code.

Product technical statements gives you further information on this.

If you use multiple suppliers for products, such as plasterboard, you must also nominate the manufacturers’ brand names and provide full details of the materials you intend to use.

This means we can approve them as part of your MultiProof and you can simply choose from these options for each individual build.

Demonstrating Building Code Compliance

As part of your application, you will need to provide enough evidence to demonstrate that your design, when built, will result in a building that complies with the relevant performance requirements of the Building Code.

To do so, you will need to provide a compliance assessment report.

The compliance assessment report lists all the relevant Building Code clauses and summarises how compliance with each clause is achieved. View an example of a compliance assessment report.

To show compliance you may be able to:

• follow Acceptable Solutions or Verification Methods to show compliance
• reference building products or methods covered by product certification or supported by any other product assurance pathway
• utilize alternative solutions

If you are proposing to use building methods, materials or products new to New Zealand and you are not able to follow one of the above pathways, you will need to provide additional supporting information.

If you plan to use a new and innovative building product, you need to provide test results of a recognised standard demonstrating the performance of the product for New Zealand conditions (such as wind and exposure zones).

You also need to provide other documentation such as installation details and maintenance requirements.

You will need to use an expert with the relevant technical expertise to:

• provide an opinion on the test methods and results
• explain how the different Standards relate to the Standards referenced in the Building Code
• translate these to New Zealand conditions.

Example

You want to use a new window product in your design. The main Building Code clauses relevant to this are:

• B1 Structure
• B2 Durability
• E2 External Moisture.

The main reference document is NZS 4211:2008 Specification for performance of windows.

For tests such as for deflection, air infiltration, water penetration and ultimate strength you need to provide separate results for the different sizes (or at least for the largest size) and types of windows you propose to use.

For durability you need to demonstrate that the frames (along with all the various elements: reveals, fixings, flashings, gaskets, glass etc.) comply with the performance requirements of Clause B2 for the various exposure zones. Refer also to Table 1 in Acceptable Solution B2/AS1 as a guide, and Verification Method B2/VM1 regarding testing and other methods.

Detail Drawings

You will also need to provide detailed drawings of the manufacturer’s installation requirements to provide compliance (such as fixings, flashings, seals etc.) for the different installation situations, along with additional details for any specific New Zealand installations.

These should include any critical dimensions that affect moisture ingress (such as for sealant to perform, to prevent capillary action, and for overlaps).

Maintenance

You may also need to provide product literature documenting any maintenance requirements that are essential to ensure that the product as installed will continue to meet the requirements of the Building Code.

Structural Design

You need to provide us with information about the adequacy of the structural system before we can approve your MultiProof application. This will include:

• a design features report
• evidence that the design intent described in the report is achieved.

The design features report tells us how you intend the structural design to work. The clearer it is, the easier it is for us to be confident about your design.

The Report Should Detail:

• which elements are structural and which are non-structural
• how loads are transferred to the foundations (for vertical and for lateral loads)
• the design standards used
• any design assumptions that have been made
• loads (snow, wind and earthquake) the building has been designed for
• assumptions or limitations that have been made about ground bearing capacity.

If your structural design is in accordance with a non-specific design standard cited in an Acceptable Solution then your report may only be a few paragraphs long.

For a one or two storey structure without unusual or special characteristics, your report should be no more than two pages long.

Providing Evidence

You need to provide evidence that the design intent you describe in the design features statement or report is achieved.

Where specific design has been undertaken, you may need to provide the following types of evidence:

• structural design calculations
• a product certificate (CodeMark)
• information from testing (this needs to be thorough and complete)
• supporting information such as manufacturer test data and literature for proprietary products or components
• a statement by an appropriately qualified Certified Professional Engineer about the adequacy of the structural system. This statement must explicitly state the basis of design (for example it is linked directly to the design features report above). In this case, we would expect you to provide the design calculations or other information relied on by the engineer.

The evidence could cover:

• all structural elements including but not limited to:
  • foundations (if included in the application)
  • floor members
  • wall, posts and columns
  • bracing elements
  • roof members
• connections between all structural elements, including the connections to the foundations.

Plumbing and Drainage

For a MultiProof plumbing and drainage should start and finish at the face of the building.

You need to show the proposed plumbing system in the MultiProof application complies with New Zealand building code. Drainage is site specific and will be assessed as part of the building consent.

You need to provide the following information in your MultiProof:

• Plumbing design – Use Standard: AS/NZS 3500.2 for the plumbing design.
• Waste, soil and water supply pipes – Specify size, fall and type of material. Include the relevant New Zealand Standard: for example, PVC pipes to AS/NZS 1260. Also include tub/washing machine pipe arrangement and both water (hot and cold) supply and waste pipes.
• Pipe insulation – Specify insulation to pipes for energy efficiency or if required for frost protection.
• Hot water heater – Specify type and energy source of water heater: for example, electric instantaneous water heater complying with AS/NZS 60335.1 and AS/NZS 60335.2.21.
• Hot Water Cylinder (HWC) –Detail drains from temperature / pressure-relief (TPR) valve and water regulating valve (such as terminate over gully) and detail or specify seismic restraint.

Specified Systems

A number of buildings contain safety and essential systems to make sure they are safe and healthy for members of the public to enter, occupy or work in.

Certain systems are known as ‘specified systems’ and require a compliance schedule (under the Building Act).

Examples of specified systems include:

• automatic systems for fire suppression (such as a sprinkler systems)
• automatic or manual emergency warning systems for fire or other dangers.

If your building design involves any specified systems, you must also include the following information with your application:

• a list and description of all the specified systems
• the performance standards for each of the specified systems
• and a description of the inspection, maintenance and reporting procedures.

This requirement does not apply to buildings used wholly as a single household unit except where a cable car is attached to it or servicing it.

Compliance schedules can explain this further.

Design Alternatives

You need to include all alternatives you are likely to use in each individual build in your MultiProof application.

If the alternatives are covered by your MultiProof you will have the flexibility to:

• cater for local conditions such as differing exposure, wind or earthquake zones
• make changes once the building consent has been issued.

To help you decide what design alternatives to include in your MultiProof application, think about the common modifications your clients request.

You must include alternatives that you consider minor. If you don’t, the BCA will assess the design as it does for any building consent application and may require that you provide additional supporting information.

The BCA’s normal 20 working day time limit will then apply.

Using MultiProof has more information about applying for a building consent with the statement.

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.

If a range of alternatives are proposed you will need to provide a design and options summary, along with an index of the plans and specifications.

These documents will make it easier for the BCA to check which of the alternatives is proposed and which documents need to be submitted with the building consent application.

This summary and the index can also be included in the public register to provide information for potential customers.

If you find you don’t have the flexibility you require, you can also apply for an amendment to your MultiProof.

Waivers or Modifications

Section 30F(2)(a) of the Building Act also allows for waivers or modifications of the Building Code to be granted as part of the MultiProof.

If you are seeking a waiver or modification you need to identify this in your application and provide a separate written request which incorporates supporting material.

The following framework will be used as a methodology for deciding if it is reasonable to grant a modification:

• The extent and possible consequence of the non-compliance with the specific performance clause.
• The availability of other reasonably practicable solutions that would result in the building work fully complying with the Building Code and associated costs.
• Any special and unique circumstances of the building work subject to the waiver or modification.
• The extent to which the modification will still be consistent with the purposes and principles of the Act.
• The modification complying with the relevant objective and functional requirements of the specific clause of the Building Code.

Housing Density

This understanding is consistent with the definition of Household unit in the A2 clause of the regulations and clause A1 2.0.2 detached dwellings which allows also for up to 6 boarders. The occupants intend to live under a single management arrangement and the owner determines those arrangements for the whole detached dwelling. 

MultiProof – Structural Design Requirements

Information about the adequacy of the structural system is needed before we can approve a MultiProof application. This will include:

• a design features report
• evidence that the design intent described in the report is achieved.

The design features report tells us how you intend the structural design to work. The clearer it is, the easier it is for us to be confident about your design.

The report should detail:

• which elements are structural and which are non-structural
• how loads are transferred to the foundations (for vertical and for lateral loads)
• the design standards used
• any design assumptions that have been made
• loads (snow, wind and earthquake) the building has been designed for
• assumptions or limitations that have been made about ground bearing capacity.

If your structural design is in accordance with a non-specific design standard cited in an Acceptable Solution then your report may only be a few paragraphs long.

For a one or two storey structure without unusual or special characteristics, your report should be no more than two pages long.

Providing evidence

You need to provide evidence that the design intent you describe in the design features statement or report is achieved.

Where specific design has been undertaken, you may need to provide the following types of evidence:

• structural design calculations
• a product certificate (CodeMark^TM)
• information from testing (this needs to be thorough and complete)
• supporting information such as manufacturer test data and literature for proprietary products or components
• a statement by an appropriately qualified Certified Professional Engineer about the adequacy of the structural system. This statement must explicitly state the basis of design (for example it is linked directly to the design features report above). In this case, we would expect you to provide the design calculations or other information relied on by the engineer.

The evidence could cover:

• all structural elements including but not limited to:
  • foundations (if included in the application)
  • floor members
  • wall, posts and columns
  • bracing elements
  • roof members
• connections between all structural elements, including the connections to the foundations.

MultiProof – Building Plans and Specifications

The drawings and specifications you submit as part of your MultiProof application should:

• describe the intended construction of the building
• demonstrate how compliance with the relevant performance requirements of the Building Code is achieved
• provide sufficient dimensions, detail and information to enable the builder to construct the building as intended
• state if all or part of the building is to be prefabricated
• define all design alternatives.

The specifications should complement the drawings. This means information on the drawings should not be repeated in the specifications, and vice versa.

A brief description on the drawings should be backed up in the specifications by:

• a full description
• statements relating to relevant reference documents
• technical trade literature.

You can also include the proposed inspection procedures and request they be approved as part of the MultiProof.

What not to include

You should not include the following in your application:

• construction outside the scope of the application
• contractual information
• site specific information
• references to ‘or equal/other approved equivalent’
• general references to clauses within an AS/NZS standard or Acceptable Solution (the actual clause should be included)
• details of work that is not required to be assessed for Building Code compliance (such as shop drawings or internal joinery details).

Components, materials and products

Your drawings and specifications should include details about components, materials and products.

This includes any product technical statements that are available from manufacturers or suppliers for critical building products or systems. Including this information tells us what items are to be used and how they comply with the relevant clauses of the Building Code.

Product technical statements gives you further information on this.

If you use multiple suppliers for products, such as plasterboard, you must also nominate the manufacturers’ brand names and provide full details of the materials you intend to use.

This means we can approve them as part of your MultiProof and you can simply choose from these options for each individual build.

Demonstrating Building Code compliance

As part of your application you will need to provide enough evidence to demonstrate that your design, when built, will result in a building that complies with the relevant performance requirements of the Building Code.

To do so, you will need to provide a compliance assessment report.

The compliance assessment report lists all the relevant Building Code clauses and summarises how compliance with each clause is achieved. View an example of a compliance assessment report.

To show compliance you may be able to:

• follow Acceptable Solutions or Verification Methods to show compliance
• reference building products or methods covered by product certification or supported by any other product assurance pathway
• utilize alternative solutions

If you are proposing to use building methods, materials or products new to New Zealand and you are not able to follow one of the above pathways, you will need to provide additional supporting information.

If you plan to use a new and innovative building product, you need to provide test results of a recognised standard demonstrating the performance of the product for New Zealand conditions (such as wind and exposure zones).

You also need to provide other documentation such as installation details and maintenance requirements.

You will need to use an expert with the relevant technical expertise to:

• provide an opinion on the test methods and results
• explain how the different Standards relate to the Standards referenced in the Building Code
• translate these to New Zealand conditions.

Example

You want to use a new window product in your design. The main Building Code clauses relevant to this are:

• B1 Structure
• B2 Durability
• E2 External Moisture.

The main reference document is NZS 4211:2008 Specification for performance of windows.

For tests such as for deflection, air infiltration, water penetration and ultimate strength you need to provide separate results for the different sizes (or at least for the largest size) and types of windows you propose to use.

For durability you need to demonstrate that the frames (along with all the various elements: reveals, fixings, flashings, gaskets, glass etc.) comply with the performance requirements of Clause B2 for the various exposure zones. Refer also to Table 1 in Acceptable Solution B2/AS1 as a guide, and Verification Method B2/VM1 regarding testing and other methods.

Detail drawings

You will also need to provide detailed drawings of the manufacturer’s installation requirements to provide compliance (such as fixings, flashings, seals etc.) for the different installation situations, along with additional details for any specific New Zealand installations.

These should include any critical dimensions that affect moisture ingress (such as for sealant to perform, to prevent capillary action, and for overlaps).

Maintenance

You may also need to provide product literature documenting any maintenance requirements that are essential to ensure that the product as installed will continue to meet the requirements of the Building Code.