Granny Flat Exemption – Key Information

Overview

 

Building an exempt granny flat

1. Plan and design your granny flat

A granny flat does not need a building consent if:

• It is a new, standalone building. Refitting or adding on to an existing building will still need a building consent.
• The building is a dwelling. This means that it is a self-contained unit that includes somewhere to cook, sleep, live, wash, and use a toilet.
• The floor area is seventy square metres (70m2) or smaller. This includes an internal garage, if applicable.
• The unit is at least two metres (2m) away from other buildings or property boundaries.
• It is designed and built (or supervised) by licensed building professionals.
• All plumbing, drainage, electrical and gas work is done by licensed tradespeople and certified.

Construction requirements

To qualify for a building consent exemption, granny flats must be built with specific materials. There are also requirements for plumbing and drainage. To be exempt, your granny flat must:

• Be built with lightweight steel/timber framing and lightweight roof cladding.
• Use wall cladding with a maximum weight of 220 kilograms per square metre.
• Be connected to network water and drainage services. If there is no network service, or enough capacity, your unit must have a compliant on-site system.
• Have showers that do not require a waterproof membrane, such as prefabricated acrylic shower units. Level entry (no-step) or wet-floor showers cannot be used.
• Not have a solid-fuel heater. Solid-fuel heaters are heat sources that burn solids like wood, coal, or pellets. These include fireplaces and wood burners.

MBIE has produced a homeowner checklist, which can be found here. For detailed requirements information, refer to the guidance on building.govt.nz.

2. Apply for a project information memorandum (PIM)

Before you start construction, you need to apply for a PIM. This is a summary of information that we hold about your property. It will tell you if there are any natural hazards or legal requirements for the land.

Request a project information memorandum (PIM)

The PIM fee is $484.10, our full fees and charges can be found here.

3. Build your granny flat

The construction of your granny flat must be done by licenced building practitioners.

Find a licenced building practitioner | lbp.govt.nz

4. Tell us what you've done

You need to tell us when you have finished building your granny flat, and provide us documents for our records. Documents must be submitted within 20 working days of building completion.

You will need to provide:

• Final design plans for the building
• Records of Work (RoW) from licensed building practitioners
• Certificates of Work (CoW) from designers for any restricted design work
• Energy work certificates, including electrical safety certificates and gas safety certificates (if applicable)
• Records of Work (RoW) from a registered plumber and drainlayer

Submit your documents online through Simpli:

Submit work records | Simpli

Development and Financial contributions

For self-contained flats (having both kitchen and bathroom facilities), your granny flat will be subject to development and financial contributions. These are costs that help pay for the unit's impact on services, infrastructure and reserves/facilities.

Financial and Development contributions are payable at completion of the build.

Development Contributions are set fees, based on the size of the unit and whether it is in the residential or rural zone. Further information can be found at Development & Financial contributions policy

Financial contributions are not set fees, but are based on 4% (plus GST) of the value of the land (net site area of a residential unit up to 1000m2). Smaller dwellings will have a lesser valuation and therefore contribution. Further information can be found at the Financial Contributions chapter of the District Plan here

We will confirm the amount of contributions payable when you apply for your PIM.

Planning Requirements - National Environmental Standards for Detached Minor Residential Units Regulations 2025 and Upper Hutt District Plan

In addition to the exemption criteria of the building act, it is important to check that your project meets all the exemption criteria under the NES-DMRU (National Environmental Standards for Detached Minor Residential Units) and any rules under the Upper Hutt District Plan (Decisions Version).

When you apply for your PIM these will be checked by our team. The full list of criteria can be found here. Some of the criteria includes: 

Zones that are permitted for Detached Minor Residential Unit (DMRU/Granny Flat) exemption				Mixed use zone Residential zone Rural Zone
	General Residential	High Density Residential	General Rural	Rural Production	Rural Lifestyle	Mixed Use
Setbacks	2m front side and rear boundaries	2m front side and rear boundaries	10m front and 5m rear	10m front and 5m rear	8m front and 3m rear	2m from all boundaries
Distance from principal unit	2m
Building Coverage	50%	70%	NA	NA	NA	NA
Detached unit size	70m2
Across all zones	A DMRU must also comply with rules and standards in the District Plan that deal with the following matters where applicable:   subdividing land protecting important natural or cultural sites using the DMRU for non-residential purposes papakāinga (communal Māori housing) earthworks any health and safety requirements that also apply to the main house – such as: natural hazards (for example: minimum floor level requirements to manage flood effects) Reverse sensitivity (for example: setbacks from neighbouring industrial sites)

If your DMRU triggers resource consent in relation to the above rules, then you must apply for and obtain resource consent before building your DMRU. A full list of Upper Hutt’s planning rules can be found on our District Plan ePlan

Our team cannot provide advice on your development without seeing your plans. If you apply for your PIM, we will review your application and provide a full breakdown on if you are likely to meet the criteria for the permitted exemption status of the DRMU or if you require a resource consent before you build. 

Infrastructure Requirements 

There are requirements and restrictions applicable to infrastructure for DRMUs, these include (but are not limited to): 

• Check that your proposed location is not being built over or near council infrastructure using our  Xplorer Maps.  
• For new water supply connections or stormwater and wastewater connections to a main, you will require a connection permit. Please apply here   

Need help?

We are here to help. If you have questions on your project you can contact the Building Duty Officer, Thursdays 1.30 PM to 4.30 PM either in person at the Council Service Centre or by phone (04) 527 2169.