In this section

The granny flats building consent exemption allows certain up to 70 square metres to be built without a building consent.

To use this exemption, all of the following must apply:

  • It must be new, single-storey, and standalone.
  • You obtain a project information memorandum (PIM) from Council,
  • All exemption conditions are met.
  • The work is carried out or supervised by licensed building professionals (LBPs).

All building work must fully comply with the New Zealand building code.

Building work must be completed within two years of the PIM issue date, and  homeowners must have all required documentation by then.

If you need more time, you can apply for an extension before the PIM expires – email building.compliance@selwyn.govt.nz.

After the build is finished, the required documents must be sent to Council within 20 working days. These will be kept on file and included with future Land Information Memorandums (LIMs).

For full details see MBIEs Granny flats exemption guidance for details.

Council’s role

We will:

  • Issue the PIM within 10 working days.
  • Store the documents you provide on your property file.

We do not:

  • Approve, inspect or certify exempt granny flats.
  • Check that the building work complies with the building code.

Council may investigate however, if there are concerns or complaints.

Important: You can continue with the build even if the PIM identifies issues but do so at your own risk.

What this means for you

As the homeowner, you are responsible for making sure:

  • All exemption conditions are met.
  • All building work complies with the building code.

Other things to know:

  • Restricted building work (RBW) must be designed and done by a licensed building practitioner (LBP).
  • Owners can do only RBW work themselves if they are an LBP.
  • If the exemption conditions are unlikely to be met, you must apply for a building consent before starting work.
  • Non-compliance can lead to enforcement action against the homeowner and/or the licensed building professional involved – eg a notice to fix and/or infringement fine.

Applying for a project information memorandum (PIM)

Use Form 2AA: Application for project information memorandum for non-consented small standalone dwelling [PDF 207KB].

What to include with your application

  • Proof of ownership – e.g.
    • Record of title
    • Lease
    • Agreement for sale and purchase
    • Other document showing full name of legal owner(s) of the building.
  • Preliminary design plans, including:
    • Site plans
    • Elevations
    • Basic sections
    • Floor plans are also recommended.
  • Product certification(s) if relevant.
  • Completed design conditions checklist.

Email all documents to building.compliance@selwyn.govt.nz.

Helpful notes

  • We also recommend submitting a completed  National Environment Standards (NES) & Earthworks form with your application to reduce the risk of getting a resource consent requirement on the PIM.
  • A granny flat may be built offsite then relocated to its intended location, and the PIM must be obtained before any building work starts.
  • If more than one granny flat is proposed on a site; each one requires its own PIM.
  • You may still need a resource consent if the activity is not a permitted activity – contact Council’s duty planner for advice.

Other considerations

  • Even if building consent is not required, all other legal requirements still apply.
  • Confirm whether you need additional approvals from Council or other authorities before you start.
  • Any development contributions listed in the PIM must be paid:
    • These help cover increased demand on local infrastructure and services.
    • Payment is due within 20 working days after the build is completed.
  • A PIM automatically lapses after two years if work is not finished. You must apply for an extension before it expires.

What qualifies as a granny flat (and what doesn’t)

A granny flat is classified as Housing – detached dwelling, and must meet all relevant requirements of the building code.

What housing - detached dwelling means

This covers a building or use where people live together as a single household – e.g.

  • A dwelling
  • A holiday cottage
  • A boarding house housing fewer than six people.

Not all small buildings qualify as a granny flat, even if they are under 70m2.

Buildings that may qualify:

  • New  work - For the purposes of the granny flat exemption, “new” means a building that:
    • did not exist before, and
    • is a separate, standalone building.

The exemption doesn’t apply if work involve altering, extending, or converting an existing building.

  • Pre-fabricated or transportable building - A prefabricated or transportable building can be considered new if:
    • it is newly manufactured or constructed, and
    • it was built on or after 15 January 2026, when the exemption came into force.
  • Imported structures - Granny flats built outside New Zealand can qualify, but all exemption conditions must be met when the building is brought into New Zealand. This means the imported granny flat must:
    • Comply with the New Zealand building code
    • Be designed and constructed by Licensed Building Practitioners (LBP)
    • Have a PIM issued before building work starts
    • Have all required documentation, including:
      • Certificate of work for design work
      • Records of work for all restricted building work
      • Safety certificates for all energy work (e.g. electrical and/or gas).
  • First building on site - A granny flat does not need to be secondary to an existing house to qualify for the exemption. This means: 
    • A principal dwelling does not have to exist on site yet
    • The granny flat can be the first building constructed on site – however, you may need a resource consent.
  • On-site wastewater disposal - If a public wastewater network system is not available or does not have enough capacity, a granny flat may use an onsite effluent disposal system (e.g. a septic tank system), provided :
    • All granny flat exemption conditions are met.
    • The system complies will all relevant requirements.

More information