Building Consent in New Zealand: What Actually Needs Consent in 2026?

Starting a renovation, extension, granny flat or new home project can feel overwhelming fast.

One builder says you don’t need consent. Someone online says you do. Council websites are full of technical wording. Then halfway through planning, you realise one small detail could completely change the process, timeline, or cost.

At MAV Studio, this is the stuff we help people navigate every day.

Whether you’re planning a renovation, a new build, a small second dwelling, or exploring the new granny flat exemptions, understanding the consent process early can save you thousands in redesign costs, delays, and stress.

This guide breaks down:

• What building consent actually is

• What work typically needs consent

• What may now be exempt in 2026

• How the new granny flat rules work

• Common mistakes people make

• How MAV helps clients navigate the process properly from the start

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What is a Building Consent?

A building consent is formal approval from your local council confirming that your proposed building work meets the New Zealand Building Code.

It exists to ensure buildings are safe, structurally sound, weather-tight, healthy to live in, and built properly.

If work requires consent, you generally cannot legally start construction until consent has been issued.

After construction, council inspections occur throughout the build, and a Code Compliance Certificate (CCC) is issued at the end confirming the work was completed in line with the approved consent.

What Projects Usually Need Building Consent?

As a general rule, most structural work needs consent.

That includes:

New Homes

Any new standalone dwelling requires building consent.

This includes:

• New family homes

• Duplexes

• Townhouses

• Transportable homes

• Cabins used as permanent accommodation

Renovations and Alterations

Consent is often required when renovations affect:

• Structural walls

• Roofing structure

• Foundations

• External cladding systems

• Waterproofing

• Fire safety systems

• Plumbing or drainage layouts

A kitchen replacement alone may not need consent. Removing a load-bearing wall beside it probably will.

Extensions and Additions

Projects like:

• Extra bedrooms

• Second storeys

• Garage conversions

• Enlarged living spaces

typically require consent because they affect structure, compliance, and often site coverage or planning rules.

Bathrooms and Plumbing Changes

Adding new sanitary fixtures like:

• Toilets

• Showers

• New bathrooms

usually requires consent because drainage and plumbing systems are involved.

Decks

Decks higher than 1.5m above ground generally require consent.

Lower decks may still require compliance with boundary setbacks or other planning rules.

Retaining Walls

Retaining walls often need consent when:

• They retain more than 1.5m of ground

• They support additional load such as driveways or buildings

Relocated Buildings

Moving a house or building onto a site requires consent and usually additional engineering and compliance work.

What Work May Not Need Building Consent?

New Zealand’s Building Act includes exemptions under Schedule 1 for certain low-risk work.

Common examples include:

• Small detached sheds within size limits

• Certain pergolas

• Low decks

• Some internal alterations

• Lightweight fences

• Minor repair and maintenance work

But this is where people often get caught out. Just because something is exempt from building consent does not mean it is exempt from:

• The Building Code

• District plan rules

• Boundary setbacks

• Site coverage rules

• Easements

• Infrastructure requirements

This is one of the biggest misconceptions we see.

The New Granny Flat Rules in 2026

One of the biggest changes in New Zealand building right now is the new granny flat exemption pathway.

As of 2026, certain small standalone dwellings may be exempt from requiring building consent if strict criteria are met.

This has created huge interest across New Zealand, especially for:

• Multi-generational living

• Rental income

• Downsizing parents

• Rural accommodation

• Additional space for teenagers or extended family

But there’s also confusion. A lot of people are hearing: “You can now build a granny flat without consent.”

That is not fully accurate, the exemption pathway is conditional and site-specific.

What Qualifies for the Granny Flat Exemption?

Current guidance generally requires the dwelling to be:

• Standalone

• Single storey

• 70m² or less

• Built by authorised professionals

• Designed to comply with the Building Code

You still need to comply with planning rules and council requirements around:

• Site coverage

• Setbacks

• Infrastructure connections

• Flooding

• Access

• Wastewater

• Zoning

Some sites will still require resource consent even if building consent is exempt. This is why feasibility matters early.

At MAV Studio, we help clients assess:

• Whether the exemption pathway is realistic

• Whether consent may still be required

• The best layout for the site

• Infrastructure and servicing implications

• Long-term value and usability

We’re already seeing cases where people purchase granny flat plans online assuming they can simply start building, only to discover later their site doesn’t qualify.

That can become an expensive mistake.

Common Consent Mistakes That Cause Problems Later

Getting consent wrong can create expensive problems later, especially when assumptions are made early without properly checking council rules, exemptions, or how the site actually performs against planning requirements.

Assuming exempt work means “no rules”

Exempt work still needs to comply with the Building Code and district planning rules.

Designing before checking the site properly

A design might look great but fail due to:

• Site coverage

• Height recession planes

• Flood overlays

• Boundary setbacks

• Easements

• Wastewater limitations

Starting work too early

Beginning work before consent is issued can create:

• Stop work notices

• Fines

• Insurance problems

• Issues when selling the property later

What Happens if You Build Without Consent?

If consent was required and work proceeds without it, councils can issue:

• Notices to fix

• Stop work orders

• Fines

• Requirements to remove or rebuild work

It can also create serious problems when:

• Selling the property

• Refinancing

• Insuring the home

Banks and buyers regularly request documentation confirming work was consented properly.

How MAV Studio Helps

This is where good early advice matters.

At MAV Studio, we help clients navigate:

• Feasibility assessments

• Council rules

• Site constraints

• Building consent documentation

• Resource consent pathways

• Granny flat exemption assessments

• Consultant coordination

• Engineering and geotech coordination

• Builder collaboration

We work nationwide and regularly help clients long before drawings are finalised.

Sometimes the best outcome is adjusting the approach early before time and money are wasted heading down the wrong path.

Thinking About Building?

Whether you’re:

• Renovating

• Adding a second dwelling

• Exploring a granny flat

• Planning a new build

• Trying to understand if consent is required

the smartest step is usually getting clarity early.

The difference between a smooth project and a painful one is often the decisions made right at the beginning.

MAV Studio helps homeowners and small developers cut through confusion around council rules, feasibility, granny flats, renovations, and new builds before costly mistakes happen.

If you're planning a project and want honest advice about what’s possible, what’s not, and what the smartest next step looks like, get in touch with the team at MAV Studio.