The rules around building granny flats in Auckland and across New Zealand have just had a significant change. Changes to the law mean that, for the first time, many small standalone dwellings can be built without a formal building consent potentially cutting cost and time for homeowners looking to add a self-contained unit to their property.

Here’s what that means, how it works, and what you still do need to consider as you plan your project.

What’s Changed?

Under recent law changes, small standalone dwellings (often called granny flats) up to 70 m² may be built without a building consent, provided all exemption criteria are met. This removes one of the biggest cost and time barriers for homeowners and is part of a wider push to increase housing supply and make better use of existing residential land.

What You Still Need to Comply With

Even without a building consent, a granny flat must still:

• Fully comply with the New Zealand Building Code
• Be built or supervised by appropriately licensed professionals
• Be notified to Council (typically via a PIM and completion notice)
• Meet planning controls, including zoning, setbacks, height, site coverage, and servicing
• Limited to one per property and there must be an existing house on the site.

In other words, the paperwork may be lighter - but the technical, legal, and design responsibilities remain.

Why You Should Still Engage an Architect

The removal of a building consent doesn’t remove the need for good design - in fact, it makes it more critical.

Here’s why working with an architect is especially valuable under the new rules:

1. Ensuring You Actually Qualify for the Exemption

Not all granny flats are eligible. An architect can assess:

• Site constraints including reviewing natural hazards and zoning rules
• Propose a design fits within exemption limits, or advise on the suitability of your site or options such as a minor dwelling with a building consent to overcome site constraints or other site factors.
• Servicing, access, and fire separation requirements

Getting this wrong can mean retrofitting compliance later at significant cost.

2. Designing to the Building Code (Without Council Checking It)

When there’s no consent, there’s also no council review of your drawings. An architect ensures the design:

• Is structurally sound
• Meets fire, moisture, insulation, and durability standards
• Is robust enough to stand up to future scrutiny (e.g. insurance, resale, or disputes)

This protects you long after construction is finished.

3. Better Use of Space (Especially Under 70 m²)

Small buildings demand smart design. An architect can:

• Make compact spaces feel generous and functional
• Optimise sunlight, privacy, and indoor-outdoor flow
• Design layouts that work for real people - not just minimum dimensions
• Design a dwelling that is specific to your site and works with your existing house.

This often makes the difference between a “basic sleep-out” and a genuinely livable home. 70m2 is more than enough for a comfortable one bedroom home and makes for a comfortable two bedroom house and is bigger than many apartments.

4. Future-Proofing Your Investment

A well-designed granny flat can:

• Increase property value
• Attract better long-term tenants
• Be easier to insure, finance and sell

Architectural documentation also provides a clear record of compliance if rules change in the future. This record must be submitted to Council along with documentation from the construction team, at the completion of the construction including any changes that were made during the construction phase.

Why It Matters

For many homeowners, this change could mean:

• Lower upfront costs: by avoiding a building consent application (and reduced fees).
• Shorter project timelines: fewer council steps can reduce delays.
• More flexibility - a broader opportunity to add a minor dwelling for family use or rental income.

Indeed, the new regime is part of a broader government push to boost housing supply and make it easier to utilise existing land more efficiently.

Tips for Auckland Property Owners

If you’re considering a granny flat:

• Check your property’s zoning rules first. Even if the building consent isn’t needed, council planning controls still apply - especially around boundaries, coverage, height and natural hazards. If your site does not meet all the requirements to comply with the building consent exemption it may still be suitable to build minor dwelling with a building consent.
• Engage licensed designers and builders early. They will ensure your design meets the exemption criteria and Building Code and help manage the council notifications.
• Budget for infrastructure charges and other costs. In Auckland for instance these can include development contributions and service connection costs (e.g., wastewater or water supply) and these need to be allowed for in your overall budget along with costs associated with a loan for the construction costs.

Final Thoughts

The 2026 changes make building a granny flat more accessible than ever before - but they don’t remove the need for good design, quality construction, or informed planning.

Engaging an architect helps ensure your project:

• Meets the exemption criteria
• Complies fully with the Building Code
• Is thoughtfully designed, durable, and future-proof

With the right team and planning, this new regime could be your chance to unlock extra space, income, or multi-generational living options on your property. If you’re thinking about building a granny flat, now is the time to start planning - because the rules have fundamentally shifted.

At Archoffice we can help step you through the whole process, design and documentation through to site observation and completion documentation.

Useful Links

1. Building Performance NZ (MBIE): Check if you need consents The authoritative source on what exactly qualifies under the new rules.
2. Auckland Council (Unitary Plan): What can I do in my zone? Advice surrounding the requirement that homeowners still need to check boundaries, coverage, and natural hazards even if a consent isn't required. This explains property zoning and provides direct access to the Unitary Plan GeoMaps.

Images copyright of Archoffice Ltd.

Article provided by Archoffice Ltd, Locally based, experienced registered architects with fresh ideas helping take your ideas into concept and reality. Ph: 021-790-908, Email: th@archoffice.co.nz, Web: archoffice.co.nz