Granny flat resource consent exemptions locked in 

The National Environmental Standards for Detached Minor Residential Units (NES-DMRU) is now in force – removing the requirement for resource consents if granny flat exceptions are met, setting national permitted activity rules for granny flats and clarifying what builders must do to avoid resource consent 

The change follows earlier uncertainty reported across the sector, where inconsistent council interpretations created confusion around when resource consent exemptions applied. The new standards establish a single national framework, setting out when a granny flat must be treated as a permitted activity. 

According to the Ministry for the Environment, the NES-DMRU “introduces new standards to simplify the process” and applies across all territorial authorities. It requires councils to permit qualifying developments, provided specified conditions are met. 

Permitted activity subject to strict criteria 

Under the NES-DMRU, a detached minor residential unit (granny flat) must be treated as a permitted activity if it complies with defined standards covering size, height, setbacks and site layout. 

For example, the granny flat must have a floor area equal to or less than 70m2.  

Building coverage must be: 

• No more than 50% in a residential zone. 

• Comply with the district plan in a rural zone. 

• Comply with the district plan in a mixed-use zone. 

• Comply with the district plan in a Māori purpose zone.  

Granny flats must be set back no less than 2m from the principle residential unit, other setback requirements include: 

• A setback of 2m from the front, rear and side boundaries of the site in a residential zone. 

• A minimum front boundary setback of 10m – with side and rear setbacks of 5m in a rural zone. 

• Compliance with setback requirements in the district plan in a mixed-use zone. 

• Compliance with setback requirements in the district plan in a Māori purpose zone. 

One granny flat per site is a permitted activity within the following district plan zones: 

• Mixed use. 

• Residential. 

• Rural. 

• Māori purpose.  

The legislation states that councils must allow construction to proceed on these units without resource consent where the conditions are met, overriding more restrictive district plan rules. The NES-DMRU allows district plans to retain more lenient permitted activity standards than those in the NES-DMRU – although varying the granny flat design to meet more lenient standards in a district plan may mean it no longer meets building consent exemption conditions.  

Parallel obligations remain under building law 

The NES-DMRU operates alongside the Building Act rather than replacing it. Builders must still obtain building consent if required, ensure inspections are completed, and meet all structural and safety requirements. 

This distinction is critical for builders delivering granny flats under the new regime. Meeting the NES-DMRU standards allows a project to proceed without resource consent, but does not reduce liability under building legislation. 

Responsibility for compliance sits with those undertaking the work. Failure to meet either planning or building requirements may result in enforcement action. 

Implications for builders 

The introduction of national standards places greater emphasis on design compliance at the outset of a project. 

Builders must ensure that proposed granny flats meet all NES-DMRU criteria before construction begins, including site-specific considerations such as boundary setbacks and overall site coverage. 

The move to a consistent national rule set provides greater certainty, but also reduces flexibility. Projects that fall outside the defined parameters cannot rely on local interpretation and will require formal consenting pathways. 

The NES-DMRU establishes a clearer regulatory environment for granny flats. For builders, the focus shifts to strict adherence – ensuring every project aligns with permitted activity standards and the requirements of the Building Act.