Building consent exemptions in New Zealand. What you can do without a building consent

Tracey Potter
Feb 9
5 min read

If you are planning a deck, pergola, fence, shed, or a backyard room, the question usually comes up early.

Do I need a building consent in NZ, or is this exempt work?

MBIE updated its guidance in January 2026, and the core principle is straightforward. Some building work does not require a building consent, however it still needs to comply with the Building Code. In addition, council planning rules can still apply even when a building consent is not required.

This article outlines the most common situations homeowners ask about, using plain language and the key thresholds that tend to matter in practice.

Before you start – three separate systems to keep clear

A lot of confusion comes from mixing these up.

Building consent
This answers whether council approval is required before building work starts.
Building Code
This sets the safety and performance standards the finished work must meet, whether or not a consent is required.
Planning rules (district plan)
These control things like height, setbacks, site coverage, and where structures can be located on a site.

Being exempt from a building consent does not mean the Building Code or planning rules do not apply.

Decks – when a building consent is usually not required

Most deck questions come down to how high the deck sits above the ground.

A deck is commonly exempt from needing a building consent if it is not possible for someone to drop more than 1.5m to the ground below, even in a worst case scenario.

What “worst case scenario” means

The measurement is the largest possible drop from the deck to the ground below, not just the neat measurement when everything is intact. On sloping sites or where the ground falls away, the biggest drop may be higher than it appears from one side.

Safety barriers are a separate requirement

A safety barrier is generally required when the drop is 1m or more, even if the deck itself does not need a building consent.

Practical deck checks

Measure the biggest drop from any edge of the deck to the ground below
If the drop is 1m or more, a compliant barrier is usually required
If the drop could be more than 1.5m anywhere, consent requirements should be checked before building

Pergolas – when they are exempt

Pergolas are generally exempt, whether attached or freestanding, and there is no size limit.

The key condition

A pergola must not be roofed.

This is where people often get caught. A pergola may be built without a roof, then roofing is added later to make it usable year round. Once roofing is added, it may no longer fall under the pergola exemption and may require a building consent.

If a covered structure is the goal from the outset, it needs to be treated as a different type of building work.

Fences and garden walls

Fences and garden walls are commonly exempt if they:

Do not exceed 2.5m in height, measured from the ground supporting the fence or wall

Two important exceptions

Pool fences are treated differently and are not covered by the standard fence exemption
Planning rules may still restrict fence height, especially on front boundaries, corner sites, or in certain zones

Fence height limits under the Building Act and under district plans are not always the same, so both need to be considered.

Sheds, sleepouts, cabins, and backyard rooms

This is where most misunderstandings occur, largely because everyday terms do not line up neatly with how the rules are applied.

A few common realities

A shed can stop being a shed once it is wired and fitted out like a living space
A sleepout can stop being a sleepout once cooking is added
A “garden studio” is not a legal category, it is a marketing term for a detached backyard room such as a home office, studio, or gym, and is treated the same way as a shed or detached building for consent purposes

What matters is size, height, distance to boundaries, and what is inside the building, not what it is called.

Detached buildings up to 10 sqm

A small detached building can often be exempt if it:

Is single storey
Stays within height limits
Does not include plumbing, a toilet, a shower, or drinking water storage

Sleeping use can be allowed in some situations when used with a dwelling, however adding cooking facilities typically removes the exemption.

In practical terms, storage sheds, workshops, and basic studios often fit within the exemption. Self contained spaces generally do not.

Detached buildings from 10 to 30 sqm

Buildings in this size range can still be exempt, but the conditions are tighter.

Common requirements include:

No plumbing, toilet, shower, or drinking water storage
Single storey and within height limits
Set back from boundaries and other residential buildings
Work may need to be carried out or supervised by a Licensed Building Practitioner
If used for sleeping, smoke alarms may be required

Once a bathroom or kitchenette is introduced, a building consent is usually required.

Kitset and prefabricated buildings

There is an exemption pathway for certain kitset or prefabricated buildings up to 30 sqm where:

The design has been reviewed by a Chartered Professional Engineer
The building is installed in accordance with that design

This can provide clearer documentation, however the same limits still apply around plumbing, bathrooms, and cooking facilities.

Granny flats and minor dwellings

If a building includes:

Cooking facilities
Bathroom facilities

It is generally moving away from simple exemptions and toward requiring a building consent, and in some cases planning approval as well.

Calling a building a sleepout does not change how it is assessed. Its layout and intended use are what matter.

Discretionary exemptions

Some building work is low risk but does not fit neatly into an exemption category. In those situations, councils may consider a discretionary exemption on a case by case basis.

Why this matters later

Building work that does not meet the Building Code, or that should have had consent and did not, can create complications later, particularly around:

buyer due diligence
insurance
lending
sale timeframes

Understanding how exemptions work before building can help avoid unnecessary issues down the track.

A practical self check

Before starting any work, it helps to be clear on:

What is being built
The size in sqm
How high it sits off the ground
How close it is to boundaries and other buildings
Whether it includes plumbing, a toilet, a shower, drinking water storage, or cooking
Whether it will be used for sleeping