Detached Minor Residential Units (Granny Flats)

The Government has changed the rules to make it easier to build to detached minor residential units (granny flats). This guidance is specific to the changes that have been made to the RMA through the new National Environmental Standard for Detached Minor Residential Units (NES-DMRU), which came into effect on 15 January 2026. A Detached Minor Residential Unit is also known as a granny flat, a minor dwelling or a small stand-along dwelling under the Building Act..

This NES will override some rules in the District Plan, unless the District Plan rules are more lenient.

This is general guidance only. Every property is different. We encourage you to contact our Customer Service Planners to clarify site specific requirements.

Under the NES-MRU, a detached minor residential unit of up to 70 square metres can be built without a resource consent, as long as the required standards are met.

In the Western Bay the regulation applies specifically to:

• residential zones
• medium density residential zones
• rural zone
• lifestyle zone
• rural-residential zone
• commercial transition zone (a mixed-use zone)

These regulations do not limit any other legislative requirements that may apply to a DMRU. Information on requirements and exemptions for building work for DMRU can be accessed here: Granny Flats (Small, Self Contained Stand-Alone Dwellings) - Western Bay of Plenty District Council.

Please contact our Building Team for further information BuildingCounterEnquiry@westernbay.govt.nz

Financial/ Development contributions still apply when constructing a DMRU.

A full version of Resource Management (National Environmental Standards for Detached Minor Residential Units) Regulations 2025 is available on legislation.govt.nz

Summarised NES-DMRU Standards

Under NES-DMRU, one Detached Minor Residential Unit per site is a permitted activity subject to meeting the following standards:

• existing principal dwelling on site
• only one DMRU is permitted per site as a permitted activity. Where a site already contains a minor dwelling, that minor dwelling is classified as a DMRU, and no additional DMRU will be permitted on the site.
• maximum floor area: equal to or less than 70sqm
• building coverage:
• residential: no more than 50%
• rural: District Plan standard applies
• setback from principal residential unit: no less than 2m
• setback from the boundary:
• residential zone: 2m from the front, side and rear boundaries of the site
• rural zone: 10m from the front boundary and 5m from the side and rear boundaries of the site

Applicants must comply with the rules and standards in the district plan that deal with the following matters if they apply to the DMRU:

• subdivision of land
• matter of national importance under section 6 of the Resource Management Act 1991 (i.e. natural hazards, natural landscape areas, heritage areas)
• the use of the DMRU other than for residential activities:
• Papakāinga
• earthworks

Applicants must still comply with the rules and standards in a district plan that:

• apply to DMRU’s Principal Residential Unit (i.e. height and daylight standards)
• The requirements set out in Sections 5 (Natural Environment), 6 (Landscape Areas), 7 (Historic Heritage), and 8 (Natural Hazards) of the District Plan, where the site is subject to these provisions. Our District Plan maps show what layers apply to your site: Map - Western Bay of Plenty Operative District Plan .
• Reverse sensitivity, as defined in the NES-DMRU. This includes additional yard setbacks and noise sensitivity requirements for DMRUs located near a strategic road, railway corridor, or designated land. These provisions are zone-specific; please view the District Plan for further details.
• If DMRU is proposed to be located on contaminated land, you need to show that the proposed activity meets the permitted activity standards under the Resource Management (National Environmental Standard for Assessing and Managing Contaminants in Soil to Protect Human Health) Regulations 2011 (SR 2011/361) – New Zealand Legislation . Details about specific properties can be viewed online via the Regional Council map gallery: Hazardous Activities and Industries List (HAIL) | BayMaps
• any site-specific infrastructure requirements such as setbacks from utilities and industrial sites
• Earthworks.
• Papakāinga (communal Māori housing).

Where a DMRU cannot meet the NES-DMRU requirements, then the usual provisions in the District Plan apply and a resource consent for a minor dwelling (or additional dwelling) will be required and assessment against any matters of discretion or assessment criteria.

It does not apply to garages, carports, sheds, or sleepouts that are not self-contained.

For DMRUs, the usual district plan rules around amenity values, minimum outdoor space, privacy, sunlight access, glazing, and parking do not apply.

If a DMRU does not meet the permitted activity standards under the NES-DMRU, the relevant district plan rules will apply instead, including any matters of discretion or assessment criteria.

The recent legislative changes also enable Development Contributions to be charged for Detached Minor Residential Units (DMRUs) at the PIM stage.

As part of your proposed development, Development Contributions may be applicable. We recommend contacting our Customer Service Planner to confirm whether Development Contributions apply to your specific project.

Further Information

Please contact our Customer Service Planner if you would like further information or refer to information in the District Plan and application form.

Please note: This information has been produced to assist you in understanding planning rules and procedures. It does not contain all District Plan or statutory requirements.

Last update: 04/02/2026