Granny flat rules in Waitaki.
Ōamaru has large established sections and demand for homes for family members, port and processing workers, health staff and tourism workers. Farms in the Waitaki Valley also need staff accommodation. A 70 m² home may suit these uses where the property meets the exemption conditions. Local considerations include heritage rules in older Ōamaru streets, flood mapping near the Waitaki River and water and wastewater systems on rural land.
Building consent and resource consent requirements
The building consent exemption and the national planning standard are separate. A project can proceed without either consent only when all the relevant requirements are met.
Schedule 1A, under the Building Act 2004
Building consent, if all Schedule 1A conditions are met
A new, detached, single-storey home up to 70 m² may be built without a building consent if every exemption condition is met. Licensed professionals, Building Code compliance, a Project Information Memorandum and council notifications are still required.
NES-DMRU, under the Resource Management Act 1991
Resource consent, if all relevant requirements are met
The national planning standard can permit one detached minor dwelling without resource consent when its standards and other relevant requirements are met. Some district and regional rules remain, including those for hazards, infrastructure and earthworks.
Both took effect on 15 January 2026. They do not retrospectively approve existing dwellings.
National planning standards
The NES-DMRU is the national planning standard for detached minor dwellings. These measurements apply when its requirements are met. A district plan can allow more generous measurements. Other relevant site restrictions still apply.
| Standard | Residential zone | Rural zone |
|---|---|---|
| Maximum internal floor areaMeasured to the internal face of the external walls. An attached or internally accessed garage counts inside it. | 70 m² | 70 m² |
| Maximum area of the site covered by buildingsThe 50% standard overrides any district plan coverage standard below 50% in a residential zone. | 50% | As required by the zone |
| Minimum distance from the main homeDistances are measured from the outside face of the wall cladding. | 2 m | 2 m |
| Minimum distance from the front boundary | 2 m | 10 m |
| Minimum distance from side and rear boundaries | 2 m | 5 m |
The permitted activity rule: One detached minor residential unit per site. It applies in residential, rural, mixed use and Māori purpose zones, as defined in the National Planning Standards, or the equivalent zones where a council has not implemented them yet.
- Special character, design guides and visual amenity
- Screening for rubbish and recycling storage
- Wall and roof colour, reflectivity and external finishes
- Minimum outdoor open space, privacy or sunlight access
- Minimum window area
- Parking
- Minimum site size
- A design that satisfies a local character guide
- A minimum private outdoor space around the unit
- A sunlight or privacy assessment for the neighbours
- An on-site car park
- A minimum site area under the district plan
- Neighbour notification for a permitted activity
Other requirements for your property
Check the district plan requirements for the property. Heritage rules in Ōamaru's whitestone precinct and older streets may affect visibility and materials. River-adjacent properties need a review of flood mapping. Rural projects also need suitable water, wastewater disposal and separation from farm effluent areas.
Flooding, coastal hazards, fault lines and land stability can affect the building location, floor level and need for consent. Check the council information and obtain site advice where needed.
Check connection requirements and capacity. Relevant regional plan rules still apply, including requirements for an on-site wastewater system.
Buildings near electricity lines and other significant infrastructure must meet the relevant safe-distance and planning requirements.
Rules can apply near airports, ports, industry and farming operations, or on contaminated land. They may affect where a home can be built and what design measures are needed.
Earthworks may need resource consent even when the dwelling does not. Subdivision requirements are separate and remain in place.
Relevant protections for heritage, cultural sites and outstanding natural features still apply.
Check covenants and easements on your property title. The national planning standard does not override private covenants, and more stringent council bylaws can still apply.
Development and financial contributions may be payable. Ask your council to confirm which charges apply to your project.
A district plan may allow a larger home or a smaller boundary setback. That does not change the separate Schedule 1A requirements. For example, an 80 m² dwelling or a 1 m setback would not meet the 70 m² and 2 m conditions for this building consent exemption.
Check the main eligibility conditions
Check these conditions with your designer and council. They are a starting point; all relevant exemption requirements must be met.
The minor dwelling must be physically separate from the principal home. An attached extension is assessed under different requirements.
The NES-DMRU planning standard requires a minor dwelling to be secondary to a principal home on the same site and in the same ownership. If both are proposed together, confirm the construction order and requirements with the council.
The NES-DMRU allows one detached minor dwelling per site. For a cross-lease, the site includes all the land under the cross-lease. A district plan may allow more, subject to its requirements.
The building consent exemption applies to new dwellings. A building conversion may meet the planning standard, but it is not covered by this building consent exemption.
Ground, climate and construction
Terrace gravels and downland clays require different foundation designs, based on the ground report. The indicative construction period is 9 to 12 weeks on site. Your builder needs to allow for access, deliveries and weather.
Steps to plan your project
Review the title, planning requirements and services with your designer, builder and council before construction.
Check covenants and easements that could restrict a second home, its size, location or access.
Review council maps and relevant district and regional rules for natural hazards, infrastructure and other restrictions.
Identify the water, wastewater and stormwater connections and confirm capacity. Check any requirements for an on-site wastewater system.
Apply for and receive a Project Information Memorandum before construction starts. It records the council information relevant to the property and proposed work.
Your designer confirms the design requirements for the property and prepares the required plans and documentation. The Schedule 1A exemption requires appropriately licensed professionals.
Notify the council before construction and provide the required completion documents afterwards. Your designer and builder must supply the records and certificates required for their work.
Frequently asked questions
Do the whitestone heritage rules affect a backyard build?+
Heritage rules may apply to properties in the whitestone precinct and older streets. A dwelling behind an existing house may have less effect on the street, but its visibility and materials still need to meet any rules that apply to the address.
What affects rental returns in Ōamaru?+
Land and construction costs both affect the return. Potential tenants include port, processing, health and tourism workers. Compare current local rents with the full project cost, ongoing expenses and an allowance for periods without a tenant.
Can valley dairy farms house staff under the exemption?+
Staff accommodation may qualify where the dwelling and property meet the exemption conditions and licensed professionals design and build it. Rural projects also need suitable water supply, wastewater capacity, service trenches, access and separation from farm effluent areas.
Anything to check near the Waitaki and its tributaries?+
Check flood mapping for land near the Waitaki River and its tributaries. Some low-lying properties need different floor levels or a different position for the dwelling. The requirements depend on the address and need to inform the design.
Official guidance
Use the official guidance below and confirm current district requirements with your council before construction.
- NES-DMRU: Frequently Asked QuestionsMinistry for Cities, Environment, Regions and Transport, September 2026 (INFO 1387)
- National Environmental Standards for Detached Minor Residential UnitsMinistry for the Environment
- Granny flats exemption guidance and resourcesBuilding Performance, MBIE
- Changes to allow granny flats to be built without a building consentBuilding Performance, MBIE
Checked against these sources in September 2026. Confirm the current requirements for your property before construction.
More information for Otago
Regional guidance and nearby council guides.