Its All Go! Granny Flat Rules – Update #6

Approved: Time to Make a Move

70m² granny flat rules in New Zealand: what you actually need to know.

On 15 January 2026, New Zealand officially approved new building rules allowing homeowners to build a self-contained granny flat of up to 70m² without a building consent. This is a significant change. It removes one of the most expensive and time-consuming barriers to building a small home.

However, and this is the critical clarification, no building consent does not mean no rules. Licensed professionals are still required, councils must still be notified, and every build must fully comply with the New Zealand Building Code.

At Cosy Cabins, our role is to make the process clear and manageable, covering planning, compliance, documentation, and construction support, so you can focus on the outcome, not the bureaucracy.

If you understand the 10 points below, you’ll already be ahead of most homeowners considering a granny flat under the new rules.

1. What the Approved Rule Change Means

As confirmed on 15 January 2026, building legislation now allows a new, standalone, self-contained dwelling up to 70m² to be built without applying for a building consent, provided all exemption criteria are met. The intent is to improve housing supply and make small, high-quality homes more accessible.

What this change does not remove:

• Professional design requirements
• Licensed Building Practitioners (LBPs)
• Full Building Code compliance
• Council involvement

This is a simplification of process, not a free-for-all.

2. Why Planning Still Matters

Even with the rules approved, good design, site checks, and council processes still take time. Homeowners who plan properly can:

• Resolve site constraints early
• Confirm compliant layouts and placement
• Avoid redesigns or consenting issues

Rushing in without preparation is where most problems start.

3. The 10 Things You Must Get Right

1. The 70m² Net Floor Area Rule

What it means: The 70m² limit is measured between the finished internal faces of the external walls.

Why it matters: Exceed the limit, even slightly, and the project may require a full building consent.

How Cosy Cabins helps: We design efficiently from the outset, ensuring layouts remain compliant while still feeling generous and comfortable.

Common misconception: Wall thickness isn’t included, but inefficient layouts can dramatically reduce usable space.

2. Single-Storey, Standalone, Fully Self-Contained

To qualify for the exemption, the granny flat must be:

• New and standalone
• Single storey (no mezzanines)
• Fully self-contained for one household

Attached or multi-storey designs do not qualify. Cosy Cabins designs are developed specifically to meet these criteria.

3. Licensed Building Practitioner (LBP) Supervision Is Mandatory

All work must be carried out or supervised by Licensed Building Practitioners. Plumbing, drainage, electrical, and gas work must be completed by licensed trades. DIY or unlicensed work can:

• Void the exemption
• Create serious compliance and resale issues

LBPs are legally responsible for code compliance and final documentation.

4. Council Notification Is Still Required (PIM)

Before construction begins, a Project Information Memorandum (PIM) must be obtained from council. A PIM identifies:

• Site services
• Natural hazards
• Infrastructure or development constraints

A PIM is not an approval. It is essential site information.

5. Natural Hazard Checks Still Apply

Councils will assess risks such as:

• Flooding
• Erosion
• Land instability

If hazards are present, design changes, or a building consent, may still be required. Early assessment prevents expensive surprises.

6. Height, Boundary, and Placement Rules Must Be Met

There are limits on:

• Overall height
• Floor level above ground
• Distance from boundaries and other dwellings

Incorrect placement can disqualify an otherwise compliant build. Design must suit the site, not the other way around.

7. “Simple Design” and Material Requirements Apply

The exemption applies to simple, lightweight construction systems. Despite no building consent:

• Full Building Code compliance is mandatory
• Structure, durability, and weather-tightness standards still apply

Shortcuts here create long-term problems.

8. Plumbing, Drainage, and Services Must Be Compliant

Services must:

• Connect to approved networks where available, or
• Meet acceptable on-site solutions

Non-compliant services are a common cause of post-build issues. Licensed installation and correct records are essential.

9. Records and Certificates Are Required at Completion

Homeowners are responsible for ensuring submission of:

• Records of Work
• Certificates of Work
• Electrical and gas safety certificates

Missing documentation can lead to penalties or resale complications.

10. The Exemption Is Not Retrospective

The exemption applies only to work started after the rule approval. Starting construction without meeting the exemption criteria can:

• Trigger full consenting
• Add unnecessary cost and delays

Correct timing and preparation matter.

4. What This Means for You

If you’re considering a granny flat for family, rental income, or flexible living, the rule approval removes a major barrier, but responsibility still sits with the homeowner. The most successful projects are:

• Properly planned
• Professionally designed
• Correctly documented

That’s how you protect both value and compliance.

5. A Clear, Supported Path Forward

The new rules remove friction, not expertise. Working with an experienced, compliance-focused builder ensures:

• Clarity from day one
• Fewer delays
• A finished home that stands up long after completion

That’s the foundation of Cosy Cabins.