Owners must meet all building consent exemption conditions. Otherwise, owners are required to get a building consent. Anything existing (built before) or building work already underway before 15 January 2026 is not eligible to be exempt from requiring a Building Consent.

Granny flats exemption: Guidance and resources | Building Performance

The Council retains its power to address non-compliant building work.

THE KEY CHANGE
From 15 January 2026, certain small standalone dwellings (commonly referred to as Granny Flats) can be built without requiring:
•    a building consent, and
•    a resource consent,
provided all statutory conditions are met.
 
This change is delivered through:
Amendments to the Building Act 2004
Building and Construction (Small Stand-alone Dwellings) Amendment Act 2025
Resource Management (National Environmental Standards for Detached Minor Residential Units) Regulations 2025
 
WHAT YOU CAN DO
You can build a granny flat without a building consent and without a resource consent if all of the following apply:
 
1: Size Limit
•    The dwelling must be 70 square metres or less (gross floor area).

2: Standalone dwelling
•    It must be a new, standalone building.

3: Simple Design
•    The dwelling must be a simple design
•    It must fully comply with the Building Code

4: Licensed Professionals
•    All building work must be carried out or supervised by Licensed Building Practitioners
•    Restricted Building Works rules still apply

5: Council notification
•    Homeowners must notify the Council:
•    Before construction starts
•    Once construction is completed

6: Resource management compliance
•    The dwelling must comply with the National Environmental Standards for Detached Minor Residential Units (NES-DMRU), or any more permissive Council rules.

The exemption does not apply to:
•    Extensions,
•    Conversions,
•    Internal alterations to existing dwellings. 
If any one of these conditions is not met, the exemption does not apply.
 
WHAT YOU CANNOT DO
The new rules do not allow you to:
•    Build a dwelling larger than 70m² under the exemption.
•    Avoid Building Code Compliance.
•    Avoid engaging licensed professionals.
•    Ignore council processes altogether.
•    Assume development contributions no longer apply.
•    Ignore site-specific constraints (hazards, servicing, access, covenants).
•    Retrospectively legalise existing unconsented dwellings.
“No consent” does not mean “no regulation”.
 
WHAT STILL APPLIES
Even where the exemption is used:
•    Project Information Memorandum (PIM)
•    A Project Information Memorandum (PIM) remains a critical step.

Councils use the PIM to:
•    Identify site-specific constraints,
•    Confirm infrastructure servicing,
•    Levy development contributions.

Development contributions
•    Councils can still charge development contributions for granny flats.
•    These are issued via the PIM process.

Documentation and Records
•    Records of Work and design memoranda must still be completed and lodged.
•    Plumbing and drainlaying records remain mandatory.
•    Enforcement and liability
•    Councils retain enforcement powers for non-compliance.
•    Insurance and resale risks remain where documentation is incomplete.
 
WHO IS RESPONSIBLE FOR WHAT
Homeowners
•    Confirm the project qualifies for the exemption.
•    Notify council before and after construction.
•    Apply for a PIM.
•    Pay any applicable development contributions.

Designers and Builders
•    Ensure the design qualifies as “simple”.
•    Ensure full Building Code compliance.
•    Complete and lodge all required documentation.

Licensed Building Practitioners (LBPs)
•    Carry responsibility for restricted building work.
•    Complete Records of Design Work and Records of Building Work.
•    Clearly explain to clients what the exemption does — and does not — cover.
This reform shifts risk away from Councils and onto Professionals and Owners. It does not remove that risk.
 
OFFICIAL SOURCES AND LEGISLATION
Primary Legislation
Building and Construction (Small Stand-alone Dwellings) Amendment Act 2025
 
Building Consent Exemption Guidance
MBIE: Granny Flats Exemption – Guidance and Resources
 
MBIE Announcement
Ready, steady, go for Granny Flats (15 January 2026)
 
Ministerial statement
Granny flat consent exemption takes effect
 
LBP guidance
Upcoming changes: granny flats building consent exemption
 
Planning Framework
National Environmental Standards for Detached Minor Residential Units (NES-DMRU)
 
 
WHAT THIS MEANS FOR THE CONSTRUCTION SECTOR AND THE PUBLIC
For the construction sector, this is a procedural reform, not deregulation. Consent processing has been reduced, but design discipline, documentation, and professional accountability increase.
 
For homeowners, the opportunity is real — particularly for:
•    Intergenerational Housing,
•    Rural and Staff Accommodation,
•    Small-scale Intensification.
However, misunderstanding the exemption carries real risk. Poor advice, incomplete documentation, or non-qualifying designs will surface later through insurance, finance, or resale.
 
THE BOTTOM LINE
This reform removes friction from the system — not responsibility.
 
Used correctly, it will:
•    Speed up delivery of small dwellings,
•    Reduce unnecessary consenting delay,
•    Support housing flexibility. 
Used incorrectly, it will simply shift risk from councils to owners and professionals.
 
As with all planning and building reform, the intent is sound. The outcome will depend on how well it is applied in practice.
 
More updates as implementation experience builds.

The Government's new 'granny flat' rules, which came into force on 15 January 2026, have been widely promoted as a win for property owners and housing supply.

Small standalone dwellings can now be built without some of the consents that previously applied, making it a simpler, low-cost process according to the narrative from Building Minister Chris Penk and Housing Minister Chris Bishop.

However, for property owners, the reality is far more complicated - and risky.

Rather than removing regulation the reforms effectively shift it. Where councils once checked compliance through formal consent processes, much of that responsibility - and risk - is now on homeowners themselves.

If you misunderstand the rules or miss a requirement, the consequences are no longer caught early. They arrive later, and they arrive expensively. This risk is also transferred in theory to the builder/designer with the safety net supposedly being implied warranties, builder's insurance and professional indemnity insurance.

The new pathway relies on exemptions under the Building Act and the National Environmental Standard for Detached Minor Residential Units (NES-DRMU). These exemptions are narrow and highly conditional. Councils still review applications through the Project Information Memorandum (PIM) process - but there is no formal approval. A PIM does not authorise construction. It simply provides information.

That matters. A PIM does not certify compliance or protect property owners from liability. It flags potential issues and leaves it to the applicant to identify, interpret and act on them correctly. Miss one, and the risk sits squarely with the property owner.

The issues commonly identified in a PIM are not minor technicalities. They can include building over boundaries, exposure to natural hazards, infrastructure requirements, development contributions, covenants or easements, and the need for resource consent under other national standards - such as contaminated land rules. Any one of these can derail a project or push it back into a full consent process after construction has already started.

The exemption does not apply to extensions, alterations or relocated buildings that existed before 15 January 2026. Assuming an older structure can be brought under the new rules is a compliance failure waiting to happen.

Even where a granny flat meets exemption criteria, the applicant needs to tick the building process regulations. All work must comply with the New Zealand Building Code and be carried out by Licensed Building Practitioners (LBPs). Work is deemed completed only when owners receive Certificates of Work, Records of Work from the LBPs, registered plumbers/drainlayers, and electrical and gas certification, and final design documentation.

From that point, strict timeframes apply. Applicants have 20 working days to pay the development contributions, if required.

Failure to get the documentation and pay the development contribution will trigger problems such as the lapsing of the PIM after 12 months from issue; likely enforcement after this point resulting in requirement to 'legalise' the work which may require lodging COA and /or building consent - costly, uncertain and stressful processes.

Long-term consequences can be even more troubling. Non-compliant buildings may create insurance problems, complicate financing, or surface years later during a property sale, when lawyers and valuers uncover missing documentation or regulatory breaches.

Granny flats can still be a valuable housing option. But property owners should go into this process with eyes wide open. Read the MBIE guidance carefully. Choose Licensed Building Practitioners wisely. Scrutinise the PIM and act on every issue it raises. And when in doubt, talk to your local council to ensure you understand ALL the rules - not after.

Under the new rules, granny flats may be easier to start - but they are far easier to get wrong.  

By Karel Boakes (BOINZ President)  

Beware the granny flat: the risks homeowners need to consider | The Post

The exemption applies only to a new building – what is “new”? - Paragraph

For the purposes of the granny flat exemption, “new” means a newly constructed standalone building that:

• did not previously exist, and
• is constructed as a separate building, rather than being created by altering, extending, or converting an existing building.

In practical terms, the exemption applies only where the building work results in a new, separate small standalone dwelling being built from scratch.

Is a prefabricated or transportable or relocated building “new”?

How or where the building is constructed (for example, off‑site in a factory) does not prevent it from being considered new.

A prefabricated or transportable building is considered “new” for the purposes of the granny flat exemption if:

·         the building is newly manufactured or newly constructed on or after the exemption came into force (15 January 2026), and

·         it has not previously been used or occupied, and

·         it is installed as a new standalone building on the site.

It must also meet all other Schedule 1A exemption requirements, such as:

• comply with the NZ Building Code
• be designed and constructed by Licensed Building Practitioners (LBP) 
• receive a PIM before building work starts
• have the required certification including a Certificate of Work for design work and Records of Work for all restricted building work, and safety certificates for energy work installations.

MBIE is continuing to review its guidance and policy as the exemption is implemented and beds in, and policy settings may be updated by the Government or refined over time to reflect emerging practice and lessons learned.

Does a PIM need to relate to the final site for a relocated building (if allowed)?

Yes. A Project Information Memorandum (PIM) must always relate to the site where the building work will be carried out.

A PIM provides information about site‑specific matters that may affect the proposed building work. For that reason, it must be issued for the land on which the building will ultimately be located.

Can a dwelling built overseas be deemed as a granny flat (work caried out overseas does not need consent)?

Currently, building work on a granny flat that is not carried out in New Zealand would need to meet the requirements of the New Zealand Building Act and Building Code when the granny flat is imported for use in New Zealand. 

For granny flats constructed offshore all the exemption conditions would apply, so the imported building would need to:

• comply with the NZ Building Code
• be designed and constructed by Licensed Building Practitioners (LBP) 
• receive a PIM before building work starts
• have the required certification including a Certificate of Work for design work and Records of Work for all restricted building work, and safety certificates for energy work installations

All other relevant exemption conditions must be met, and there is information explaining these in MBIEs guidance Granny flats exemption: Guidance and resources | Building Performance.

MBIE is continuing to review its guidance and policy as the exemption is implemented and beds in, and policy settings may be updated by the Government or refined over time to reflect emerging practice and lessons learned.

What does “associated with an existing dwelling” mean?

For the building consent exemption there is no requirement that a principal or main dwelling already exists, or the granny flat be secondary to another dwelling at the time of construction. The exemption does not depend on the order of construction (main house first vs granny flat first).

The phrase “associated with an existing dwelling” commonly arises from planning rules, not the Building Act. In particular under the Resource Management Act and the National Environmental Standards for Detached Minor Residential Units (NES‑DMRU), a minor residential unit is often required to be associated with an existing principal dwelling to be permitted without resource consent.  

This means a granny flat may be exempt from building consent, but still require resource consent, if planning rules are not met.

Can a granny flat be built on an empty section? / Is it possible for a granny flat to be built prior to the main dwelling?

Yes. However, it is important to distinguish between building consent requirements and resource consent / planning requirements:

Building Act 2004 (building consent exemption)
The Schedule 1A exemption does not require the granny flat to be associated with an existing dwelling at the time it is built. A granny flat may therefore be constructed first, or as the only dwelling on a site, without a building consent, provided all exemption conditions are satisfied.

Resource Management Act / NES‑DMRU (planning rules)
Planning rules are separate. In most cases, the National Environmental Standards for Detached Minor Residential Units (NES‑DMRU) require a minor residential unit to be associated with an existing principal dwelling in order to be permitted without resource consent. The exception to this is where a district plan would otherwise have more permissible rules (eg. would not have required a resource consent prior to the NES-DMRU coming into effect).

As a result, while a granny flat may be exempt from building consent on an empty section, it may still require resource consent, depending on the applicable planning framework.

Can a granny flat be associated with a main dwelling but on a separate section/ land title?

The Building Act does not recognise an “association” between dwellings on different titles. If a granny flat is built on a separate section, it is assessed as a standalone dwelling on that section, regardless of whether there is a main dwelling on another nearby title.

This is reflected in the way the exemption operates:

• a Project Information Memorandum (PIM) must be issued for the site where the granny flat will be built, and
• the exemption conditions, including natural hazard considerations, apply to the land the building is on, not to neighbouring or related titles.

It is also important to distinguish between building consent requirements and planning (resource consent) rules. The idea of a granny flat being “associated with” a main dwelling comes from planning rules (such as the NES‑DMRU), not from the Building Act. Meeting the building consent exemption does not determine whether resource consent is required.

How many granny flats can be on a site and/or section? NES-DRMU indicates one but the Building Act suggests it could be many.

Under the Building Act, there is no specified limit on the number of granny flats that can be built on a site for building consent purposes, provided that each granny flat independently meets all of the Schedule 1A exemption conditions.

In principle, this means more than one granny flat could be built under the building consent exemption, as long as all conditions are met for each dwelling.

The National Environmental Standards for Detached Minor Residential Units (NES‑DMRU) are separate from the Building Act. The NES‑DMRU generally provide for one minor residential unit per site as a permitted activity.

Where more than one granny flat is proposed on a site, this is likely to exceed what is permitted under the NES‑DMRU and may require resource consent, even if the granny flats meet the Building Act exemption conditions. There could also be natural hazard considerations as well depending on the nature and size of the section.

While aligned, the building consent exemption and planning rules operate independently. Meeting the Building Act exemption does not determine whether a proposal is permitted under the NES‑DMRU, and vice versa.

What is classed as own independent source of power?

An independent source of power means that the granny flat is supplied by a single, dedicated electricity supply arrangement for that dwelling. This ensures the granny flat can be safely supplied, isolated, and managed independently of any other dwelling on the site.

An independent source of power does not necessarily require a new connection from the electricity network. A granny flat may be supplied from an existing connection on the site, provided that:

• the granny flat has its own independent switchboard and circuits, and
• the supply is not taken from the main dwelling’s internal wiring (for example, it must not be connected via a shared household circuit or extension lead).

Whether an existing connection can supply both dwellings will depend on:

• the capacity of the existing connection, and
• compliance with the Electricity Act and associated regulations 

These matters are to be determined by a registered electrician and the local lines company. Upgrades may be required to ensure the supply is safe and compliant.

What are onsite effluent disposal system requirements?

Where a network wastewater system is not available or does not have sufficient capacity, a granny flat may use an onsite effluent disposal system (for example, a septic tank system), provided all exemption conditions are met.

For the purposes of the granny flats building consent exemption:

• an onsite effluent disposal system must be designed, installed and operated to comply with an existing AS or VM e.g. G13/VM4, designed to AS/NZS1547:2012
• the system must be appropriate for the site conditions and the expected loading from the granny flat e.g. 30 fixture units.
• if an existing onsite system is proposed to be used or modified, it must have sufficient capacity and condition to service the additional dwelling. This may require a review of an existing building consent of resource consent.

Compliance may involve assessment against or other relevant technical standards, as appropriate.

Regional council rules relating to wastewater discharges to land continue to apply. The building consent exemption does not override regional plan requirements or any resource consent requirements for effluent disposal. Any separate approvals required under regional rules must still be obtained.

Does an onsite effluent disposal system need to be a new one or can an existing system be used or modified?

An onsite effluent disposal system does not need to be a new system. An existing onsite effluent disposal system may be used or modified, provided it can be demonstrated that the system:

• has sufficient capacity to service the granny flat, and
• is in a suitable condition to continue to operate effectively.

Under the building consent exemption, the owner is responsible for ensuring that any onsite effluent disposal system used for a granny flat complies with the Building Code. Where an existing system is relied on, the owner is responsible for obtaining appropriate professional advice or assessment to demonstrate that the system has adequate capacity and is suitable for continued use. This may include assessment against G13/VM4, AS/NZS1547:2012.

Because this is a building consent exemption, councils:

• do not approve or certify onsite effluent disposal systems for granny flats, and
• are not required to assess or verify system capacity or condition.

Any information prepared to demonstrate capacity and condition forms part of the owner’s due diligence and project documentation.

Regional council rules relating to wastewater discharges to land continue to apply. The building consent exemption does not override regional plan requirements or any resource consent requirements for onsite effluent disposal.

How can the capacity and condition of an existing onsite wastewater system be confirmed under NZS1547?

Under the granny flats building consent exemption, under G13/VM4, AS/NZS 1547:2012 is used as a recognised technical standard to assess whether an onsite wastewater system is suitable, rather than as an approval or certification process.

Confirming capacity and condition under AS/NZS 1547:2012 means that a suitably qualified professional assesses whether the existing onsite wastewater system:

• Has capacity to service the additional wastewater loading from the granny flat, and
• is in a condition that allows it to continue operating effectively.

The outcome of an AS/NZS1547:2012 based assessment forms part of the owner’s evidence that the exemption conditions are met and supports the owner’s obligation to ensure Building Code compliance.

Because this is a building consent exemption:

• councils do not assess or certify onsite wastewater system capacity or condition under AS/NZS 1547:2012, and
• councils may rely on the owner and their professionals to ensure appropriate assessment has been undertaken.

Information may be requested by a council if compliance is later questioned, or through other processes (for example, regional council requirements), but it is not a pre‑approval step under the Building Act exemption.

Regional council rules relating to wastewater discharges to land continue to apply. Any resource consent or discharge authorisation requirements under regional plans must still be met, regardless of the building consent exemption.

How can the capacity and condition of an existing onsite wastewater system be confirmed under NZS1547?

Under the granny flats building consent exemption, under G13/VM4, AS/NZS 1547:2012 is used as a recognised technical standard to assess whether an onsite wastewater system is suitable, rather than as an approval or certification process.

Confirming capacity and condition under AS/NZS 1547:2012 means that a suitably qualified professional assesses whether the existing onsite wastewater system:

• Has capacity to service the additional wastewater loading from the granny flat, and
• is in a condition that allows it to continue operating effectively.

The outcome of an AS/NZS1547:2012 based assessment forms part of the owner’s evidence that the exemption conditions are met and supports the owner’s obligation to ensure Building Code compliance.

Because this is a building consent exemption:

• councils do not assess or certify onsite wastewater system capacity or condition under AS/NZS 1547:2012, and
• councils may rely on the owner and their professionals to ensure appropriate assessment has been undertaken.

Information may be requested by a council if compliance is later questioned, or through other processes (for example, regional council requirements), but it is not a pre‑approval step under the Building Act exemption.

Regional council rules relating to wastewater discharges to land continue to apply. Any resource consent or discharge authorisation requirements under regional plans must still be met, regardless of the building consent exemption.

Does a BCA need to confirm regional rule requirements around discharge to ground e.g. with respect to effluent discharge, should the BCA insist on a design at application stage to show compliance?

Under the granny flats building consent exemption, BCAs are not responsible for confirming compliance with regional council discharge‑to‑ground rules.

Regional wastewater requirements remain the responsibility of the owner and the relevant regional council, and BCAs should not require wastewater design information as part of administering the building consent exemption.

A BCA may:

• clearly advise owners that regional rules still apply, an
• direct owners to the relevant regional council for advice on effluent discharge requirements.

What responsibility does Council have to confirm the granny flat designer is an LBP when the application is received? Applications for Granny flat exemptions are only vetted not checked by Councils so plans not drawn by an LBP would not necessarily be picked up at the time of receipt.

Submitting preliminary plans that have not been prepared by a suitably licensed designer does not in itself mean that the building work fails to qualify for the Schedule 1A exemption at the PIM stage.

The PIM process is a notification and information provision step, not an approval or assessment of exemption eligibility or Building Code compliance. Preliminary plans submitted with a PIM are used to help describe the proposed building work and identify relevant site information. They are not treated as the final design for the purposes of determining whether restricted design work has been lawfully carried out.

Design work for a granny flat will involve restricted building work, and under section 84 of the Building Act, restricted design work must be carried out or supervised by an appropriately licensed designer. If that requirement is not met by the time restricted design work is relied on for construction, the building work will not qualify for the exemption and the usual compliance and enforcement provisions of the Act may apply.

In practical terms, this means councils should accept and process the PIM application, clearly advise applicants of their restricted design work obligations and seek clarification where information is missing or unclear, without treating this as a refusal or eligibility decision.

What happens if on lodgement of the final documents it is established that the designer is not an LBP? Does that negate the whole project? (It is noted that Council does not have responsibility for checking content of the documents.)

Because councils do not check or approve design content for consent‑exempt granny flats, the issue will usually arise because the owner is unable to provide a valid Certificate of Design Work (CoW) at completion.

Because councils do not check or approve design content for consent‑exempt granny flats, the issue will usually arise because the owner is unable to provide a valid Certificate of Design Work (CoW) at completion.

Under the granny flats building consent exemption:

1. restricted design work must be carried out or supervised by an appropriately licensed person (for example, an LBP (Design), Registered Architect, or CPEng).
2. evidence of this is provided through a Certificate of Design Work on completion
3. the owner must provide all required completion documentation to the council within 20 working days of completion. This includes a Certificate of Design Work for restricted design work

If the designer is not an LBP (or equivalent), the owner:

• cannot obtain a valid Certificate of Design Work, and
• cannot meet the documentation requirements of the exemption.

Without a valid Certificate of Design Work a mandatory exemption condition is not met, the building work cannot be treated as having been completed under the Schedule 1A exemption and an alternative compliance pathway is required for example a Certificate of Acceptance.

Can a definition of what constitutes light timber or steel framing be provided?

For the purposes of the granny flats building consent exemption (Schedule 1A), light timber or light steel framing refers to a structural framing system where the primary load bearing structure is made of lightweight timber or cold formed steel members, consistent with typical low rise residential construction in New Zealand.

Light timber framed buildings are commonly designed and detailed in accordance with NZS 3604, or to an equivalent engineered solution that still uses a light timber framing system as the primary structure.

Light steel framing generally means cold formed light gauge steel framing, and wall, floor and roof framing systems consistent with standards such as the NASH Light Steel Framed Buildings Standard.

Can other Building Act exemptions also apply to a granny flat?

Other Schedule 1 building consent exemptions do not apply to the construction of a granny flat. A granny flat must be built entirely under Schedule 1A or under a building consent. 

Once a granny flat has been lawfully completed, Schedule 1 exemptions may apply to future work in the same way as for any other dwelling.

At what stage, if any, can additional building work be undertaken that does not require a building consent (for example, decks or verandas), and must such work only occur after the granny flat has been completed and confirmed as lawfully established under Schedule 1A?

A granny flat must be constructed to comply fully with the requirements of Schedule 1A of the Building Act 2004, or a building consent is required. 

Other work that is exempt under Schedule 1 or carried out under a building consent that does not comply with the conditions of schedule 1A should not modify any part of the granny flat itself before it is completed.

Schedule 1 exemptions may still apply to other, separate building work on the site, provided the relevant exemption criteria are met and the work does not affect the granny flat’s compliance with the exemption conditions and/ or Building Code compliance.
 
Three common scenarios explaining how this would work and be permissible in practice:
 
1.    The granny flat is deemed complete (as set out in section 42B) and meets all Schedule 1A conditions. After completion, a deck is built on the granny flat and it independently meets the Schedule 1 exemption criteria.
2.    The deck is built at the same time as the granny flat and forms part of or is integrated with the dwelling and both the deck and granny flat meet all Schedule 1A conditions.
3.    The granny flat is being built and meets all Schedule 1A conditions. The deck is built at the same time and is physically and functionally separate from the granny flat (by the 2m minimum separation) and independently meets the Schedule 1 exemption criteria.

What should a BCA do  when it sees obvious noncompliance to Building Act Schedule 1A ( 2) Requirements for a small standalone dwelling (e.g. no light timber/steel framed is 6m high or has a ground level over 1m)?

Where a BCA identifies building work that is clearly outside the scope of Schedule 1A (for example, the dwelling is not lightweight timber or steel framed, exceeds the permitted height, or has a finished floor level more than 1 metre above ground), the matter should be treated in the same way as any other building work being carried out without a required building consent.

The exemption does not create a separate or alternative compliance regime. Once it is clear that the Schedule 1A conditions are not met, the project simply falls back into the standard regulatory framework under the Building Act.

Responsibility for ensuring eligibility for the exemption rests with the owner and their engaged building professionals, not with the council.

How should changes to the design of a granny flat that occur during the build, be treated?

Any change to the design must be considered against the Schedule 1A conditions and the Building Code. Even minor changes can affect eligibility for the exemption. If a change means the building work no longer meets the Schedule 1A requirements, the exemption no longer applies and building work must stop until a building consent is obtained. 

Changes that do not affect eligibility for the exemption should be managed through standard design and construction practice. Licensed building professionals remain responsible for ensuring that:
•    the building continues to comply with the Building Code, and
•    the work remains within the scope of Schedule 1A.

All design changes made during construction must be fully and accurately documented, including:
•    updating plans and specifications to reflect what is actually built
•    issuing updated Certificates of Design Work (CoDW) where                   restricted building work design has changed
•    ensuring Records of Work (RoW) clearly reflect the work carried out or supervised.

At completion, the final design plans provided to the owner and council must show the as built outcome, including all variations made during construction. These documents form part of the permanent property record and may be relied on for future alterations, compliance, insurance or sale of the property.

How should additional building work done on the site be treated if the granny flat is incomplete? 

A PIM will automatically lapse if the building work is not completed within two years of the PIM being issued. To avoid this, a homeowner must apply to the council for an extension before the two-year deadline. 

If the granny flat is not completed and the PIM lapses, the granny flats exemption no longer applies. 

If the PIM lapses before the granny flat is complete the homeowner may need to apply for a certificate of acceptance for building work already completed and/or building consent to obtain regulatory approval for the remaining building work.

Is it appropriate to accept and process building consent applications for work outside the granny flat exemption prior to final confirmation that the granny flat has been lawfully established? 

Whether it is appropriate to accept and process a building consent application for work outside the granny flat exemption before final confirmation that the granny flat has been lawfully established is ultimately a matter for each council to determine, based on its own systems and operational practices. A PIM will automatically lapse if the building work is not completed within two years of the PIM being issued. To avoid this, the homeowner must apply to the council for an extension before the two-year deadline.

However, a granny flat built under the Schedule 1A building consent exemption must be completed in accordance with all exemption conditions before it is treated as a lawfully established dwelling. The exemption applies to the entire dwelling as a whole, and compliance must be maintained throughout construction. Building work that is intended to be carried out under a building consent and that forms part of, modifies, or relies on the granny flat itself should not begin until the granny flat has been completed under the exemption. This avoids overlap between exemption and consent pathways.

Councils may choose to accept and process a building consent application in advance (for example, for future work) or defer processing until the granny flat has been confirmed as complete, provided that no consented work affecting the granny flat itself is carried out until the exemption pathway has been properly completed.

The timing that matters is when consented building work begins, rather than when the application is processed.

Would accepting an application for other building work on the same site as an incomplete granny flat undermine reliance on the exemption provisions or create unintended compliance or enforcement risk for Council?

See answer above.

How will future alterations to a granny flat be treated?

Once a granny flat has been lawfully completed under the Schedule 1A building consent exemption, it is treated as a lawful existing dwelling for the purposes of the Building Act.
After completion:
•    the granny flat is no longer assessed under Schedule 1A, and
•    future building work is assessed in the same way as for any other         existing dwelling.
This means that any later alterations, additions, or upgrades must follow the appropriate regulatory pathway based on the nature of the proposed building work.

Is there anything to stop a 3-level granny flat being built 2m from the front boundary with a building consent? To help clarify this and provide some context around the reason for asking, I’ve received the following additional explanation:

The NES does not specify the 1 level requirement just that it must be less than 70m2. The building act exemption does say one level so would not fit this criteria but if you obtain a BC then you can legally build 2m from the front or side boundary 2 or even 3 storey’s high and be legally complaint with the planning rules. Issues around sunlight protection for neighbours etc. The NES and Building Act exemptions are not linked in any way, you can use each one separately.

The Building Act does not prevent a two or three storey dwelling being built close to a boundary where a building consent is obtained and the proposal complies with the Building Code and the applicable planning rules.

The granny flat building consent exemption (Schedule 1A) applies only to a narrow set of buildings, including a requirement that the dwelling is single storey. A building that does not meet those conditions cannot use the exemption and must instead be built under a building consent.
Once a building consent is used, the Schedule 1A design limits no longer apply. Building height, number of storeys, and setbacks are then managed through:
•    the Building Code (building performance and safety), and
•    the planning framework (NES DMRU, district plan rules, or a resource consent where required).

The NES DMRU and the Building Act exemption operate independently. Meeting (or not meeting) one does not determine whether the other applies.

Schedule One of the Building Act 2004 sets out the building projects that do not require Building Consent, ie are exempt work. If you have questions about the exemptions contained in Schedule One, and after you have read the Exempt Building Work Information you should contact the Building Consent Authority.

The list below is a summary of, but not limited to, building work that may not need a consent:

• certain structural building work relating to minor additions, alterations, re-piling, some demolitions
• plumbing and drainage where the number of sanitary fixtures is not increased including some repair and maintenance)
• installing an air-conditioning system into a residential dwelling
• retaining walls less than 1.5 metres in height that do not have a surcharge or 3.0 metres high in rural area if designed by a chartered professional engineer
• fences or walls less than 2.5 metres high (any residential swimming pool fencing is not exempt)
• decks, platforms or bridges less than 1.5 metres above ground level
• certain earthworks.
• SOME single-storey detached buildings such as sleepouts, sheds and greenhouses up to 30 square metres (see 'Sleepouts' and 'Accessory Buildings'). 
• Carports (up to 40 square metres )
• Ground floor awnings, verandas and porches (up to 30 square metres).
• Repairing and replacing some existing building elements. 

Solar panel arrays, permanent outdoor fireplaces or ovens, water storage bladders for irrigation and firefighting purposes, short-span small bridges, hay barns and pole sheds are also included.

Even though these building projects may not need a building consent, all work must meet the Building Code and some work requires a professional. Some projects also require Resource Consent (see 'Resource Consents' tab in the side bar). It's important that homeowners know there are still rules that need to be followed.

If you own the property, you own the responsibility. This means you must check whether your building project requires a Building Consent or Resource Consent.

All the information you need to make your decision is available at https://www.building.govt.nz/buildit

Important note

An exemption, of itself, does not permit building work if that building work would be in breach of any other Act e.g. the Resource Management Act 1991, as exempt building work may still require planning approval (Resource Consent) or a Services Consent (connection to sewer, water, storm water).

All exempt building work, including discretionary work, is the responsibility of the building owner to ensure compliance with the Building Code is achieved, as council will not be inspecting any building work.

If your proposed work doesn't fit into any of the exemption requirements, there is an option for you to seek a "Discretionary Exemption". This approval process must be sought (from Council) if you wish to have your building work considered using Schedule 1, Clause 2. There are many considerations pertaining to this process. 

It is worth noting that the Discretionary approval process is a "one off" chance for the owner or applicant to demonstrate compliance, meaning council will not be requesting further information (RFIs).