Building a Granny Flat Without Building Consent—What Are the Limits?

 

New Zealand’s granny-flat rules changed on 15 January 2026.

Certain new, standalone dwellings of up to 70 square metres can now be built without obtaining a building consent. This provides a simpler pathway for qualifying projects, but it does not create an unrestricted right to build any small dwelling anywhere.

The exemption contains detailed conditions. Property owners must also consider planning rules, natural hazards, services, council notifications and professional supervision.

“Consent exempt” does not mean “rule free”.

What the exemption allows

The exemption applies to certain new, single-storey, standalone dwellings with a net floor area of no more than 70 square metres.

The design must be simple, the work must comply with the Building Code and construction must be completed or supervised by licensed building professionals.

The homeowner must notify the local council before construction begins and again after completion.

These requirements are designed to reduce consenting cost and delay while maintaining professional accountability.

The exemption applies only when every condition is met. If the proposed design falls outside the exemption, a building consent will still be required.

Building Code compliance is still mandatory

All building work in New Zealand must comply with the Building Code, including exempt work.

That means a granny flat must still meet requirements relating to:

• Structure.
• Fire safety.
• Access and safety.
• Moisture.
• Services and facilities.
• Energy efficiency.
• Durability.

The lack of a traditional building consent process places more responsibility on the homeowner and licensed professionals to confirm compliance.

Owners should resist the temptation to use incomplete plans or unverified products. The dwelling will need to remain safe, dry and durable long after construction is complete.

Planning rules remain separate

Building consent requirements and resource-management requirements are different.

A granny flat may qualify for the building consent exemption but still fail to comply with planning controls such as boundary setbacks, site coverage, height, outlook or natural-hazard requirements.

The National Environmental Standards for Detached Minor Residential Units also came into force on 15 January 2026. They provide a separate pathway for qualifying units to proceed without resource consent when the applicable standards are met. The resource-management standards and building consent exemption can operate independently.

Property owners should confirm both pathways before finalising the design.

Council records, easements, covenants and development controls may also affect the site.

Services require early investigation

Wastewater, stormwater, water, power and telecommunications can determine whether a granny-flat project is practical.

A site may have enough physical room for the dwelling but insufficient wastewater capacity. Existing private drainage may need alteration, while some sites may require pumping or upgraded connections.

Stormwater treatment and discharge must also be considered. Adding a roof and paved access increases impermeable area.

These issues should be assessed before detailed design begins. Service upgrades can significantly affect the total project cost.

Ground conditions and natural hazards

A small dwelling still needs a reliable foundation.

Sloping land, uncontrolled fill, flooding, liquefaction potential and poor bearing conditions may require engineering input or move the project outside the simplest design pathway.

A Land Information Memorandum and council hazard information can help identify known constraints. Building Performance guidance recommends professional engineering advice where sites are within identified liquefaction hazard areas.

Owners should avoid assuming that a lightweight or compact dwelling can be placed on any available part of a section.

Professional supervision

The exemption requires qualifying work to be carried out or supervised by licensed professionals.

This is important because there may be fewer council inspection points than under a conventional building consent.

The project team should maintain good records, including:

• Approved plans and specifications.
• Product information.
• Licensed professional details.
• Construction photographs.
• Producer statements where relevant.
• Electrical and plumbing certificates.
• Council notification records.
• Completion information.

These records can be valuable when the property is sold, refinanced or insured.

Granny flats and multi-unit construction

A single minor dwelling is not automatically a multi-unit development. However, the same construction principles apply.

The main house and granny flat must work together on one property. Parking, privacy, outdoor space, access, drainage and services require coordinated planning.

Where a developer proposes several dwellings or a larger grouped development, the project is more likely to require conventional building and resource consents.

A commercial construction company experienced in multi-unit construction can help identify where a simple minor dwelling ends and a more complex development begins.

Establishing a realistic budget

Removing the building consent requirement does not remove the cost of design, professional supervision, siteworks or compliant construction.

A complete budget should include:

• Design and technical documentation.
• Surveying and site investigation.
• Engineering where required.
• Council notifications and development contributions.
• Service connections or upgrades.
• Earthworks and foundations.
• Construction.
• Driveways, paths and landscaping.
• Professional records and certification.

Owners should be cautious about headline prices that exclude site-specific work.

Choosing a construction partner

A successful granny-flat project requires a builder who understands the exemption conditions and recognises when specialist advice is needed.

The contractor should use documented plans, approved materials and clear quality-control processes.

For clients considering a granny flat as part of a larger development strategy, it can be useful to consult a commercial construction company familiar with both standalone and multi-unit construction.

Opportunity with responsibility

The new exemption may make it easier to create accommodation for relatives, rental income or flexible household use.

It should not be treated as a shortcut around sound design and proper construction.

The best projects will begin with site checks, realistic budgeting and a clear understanding of the legal pathway.

Savannah Construction undertakes residential, commercial and multi-unit construction across the Waikato. Details about the business and its project capability can be found at www.savannahconstruction.co.nz.