Harvey Newport — Licensed Building Practitioner
Building Advice
One of the first questions homeowners ask when planning a renovation is:
‘Do I actually need building consent for this?’
Sometimes the answer is obvious. If you are adding a large extension, altering structural walls or substantially changing the building envelope, a building consent will normally be part of the project.
Other renovations are less clear. Replacing internal linings, moving kitchen cabinetry or carrying out some maintenance work can often be done without building consent. Then there are projects that sit somewhere in between — bathrooms, internal layout changes, new doors and windows, decks or plumbing alterations — where the exact scope determines what approvals are required.
The important point is to work this out before construction starts, rather than after part of the house has already been pulled apart.
The simple answer: it depends on what you are changing
Under the Building Act, most building work requires a building consent unless it falls within an exemption.
Schedule 1 of the Building Act contains a range of exemptions for lower-risk work. But, as discussed in our article about replacement windows and the Building Code, exempt work must still comply with the New Zealand Building Code.
MBIE’s current guidance makes this distinction clear: structural work including additions and alterations will commonly require consent, while certain lower-risk work can proceed under a Schedule 1 exemption.
For a homeowner, the useful question is not simply ‘Is this a renovation?’ It is ‘What individual pieces of building work are included in the renovation?’ A single renovation may contain both consented and exempt work.
Renovation work that commonly needs building consent
Projects that commonly require building consent include work involving:
additions and extensions;
structural changes;
removing or significantly altering load-bearing walls;
repiling;
substantial changes to the exterior envelope;
new plumbing or drainage in situations not covered by an exemption;
certain tiled or wet-area shower installations;
decks where the relevant height threshold is exceeded; and
other work where compliance with structural, moisture, fire or safety requirements needs to be formally assessed.
Building Performance lists additions, structural alterations and repiling among work that generally requires consent. Kāpiti Coast District Council provides similar guidance for additions, alterations, repiling and plumbing or drainage work unless a specific exemption applies.
That does not mean every renovation becomes complicated. It simply means the design and consent pathway should be established before work begins.
Renovation work that may not need building consent
There is also plenty of work that can be exempt. A good example is internal linings.
Building Performance confirms that replacing or altering internal wall, ceiling and floor linings in an existing dwelling can be exempt from building consent. That exemption is quite broad, although care is still required where the linings form part of a bracing or fire-resistance system.
Depending on the circumstances, other maintenance, repair and replacement work may also be exempt. The key issue is that exemptions have conditions.
It is risky to take a broad statement such as ‘You don’t need consent for internal renovations’ and apply it to an entire project. You might not need consent to replace plasterboard, but you may need consent if the same renovation also involves altering structural framing or adding plumbing fixtures in a way that falls outside the exemptions.
Kitchens and bathrooms: where homeowners often get caught out
Kitchen and bathroom renovations are a good example of why the details matter.
Replacing kitchen cabinetry, benchtops, flooring or finishes does not automatically mean you need building consent. But once you start altering plumbing, installing new sanitary fixtures, moving showers or creating new wet areas, the requirements can change.
Hutt City Council’s kitchen and bathroom guidance advises that consent is required for work such as new drains, new toilets or showers where there was not one previously, and tiled wet areas. It also notes that some minor plumbing or drainage alterations can be exempt, although the work must still comply with the Building Code and plumbing or drainlaying rules.
That is why a bathroom renovation should be scoped properly before demolition. A project that starts as ‘We are just updating the bathroom’ can quickly become a consented project if the layout changes significantly.
Removing or changing walls
Removing a wall is another area where the answer depends on what the wall actually does.
A non-load-bearing partition may be relatively straightforward. A wall that supports roof framing, floor framing or another structural element is different. Removing or modifying structural elements generally requires design consideration and often building consent.
The same can apply where an internal wall forms part of the building’s bracing system. Modern homes commonly rely on specific wall lengths and plasterboard systems to resist wind and earthquake forces. Removing one of those walls without checking the bracing design can affect the structure even if the wall does not appear to be carrying vertical loads.
For Wellington homes in particular, structural and bracing considerations should not be treated as an afterthought.
Extensions and changes to the exterior
If your renovation increases the footprint of the home, you should expect building consent to form part of the planning process.
Extensions involve more than simply adding floor area. They can affect foundations, structure, bracing, roofing, external moisture, insulation, windows and doors, stormwater, boundary clearances and sometimes resource-consent requirements.
New building work forming part of an alteration must comply with the applicable Building Code provisions. For existing buildings being altered, the wider building must also continue to comply to at least the same extent as before the alteration.
This is one reason it makes sense to involve the builder and designer early rather than completing the design in isolation and pricing it afterwards. You can learn more about Newport Construction’s approach to renovations and extensions.
Building consent and resource consent are different
Homeowners sometimes assume that if building consent is not required, no other approvals are required. That is not necessarily the case.
Building consent deals primarily with how building work complies with the Building Act and Building Code. Resource consent and District Plan rules look at different issues, including building location, site coverage, height, boundary relationships, earthworks, natural hazards and effects on surrounding properties or the environment.
A project can require a building consent, a resource consent, both, or potentially neither depending on the proposal. The same basic principle applies throughout the Wellington region.
What happens if the design changes during construction?
Renovations rarely go exactly as originally drawn. Once walls, ceilings and floors are opened up, unexpected framing, old plumbing, rot, wiring or previous alterations can appear.
Small changes to an approved building consent may sometimes be dealt with as a minor variation. Larger or more significant changes require a formal amendment.
The important point is that the variation or amendment needs to be dealt with before the affected work proceeds. That is another reason good communication between the owner, builder, designer and council matters during a renovation.
The best time to check consent requirements
The best time to establish the consent pathway is before detailed drawings and pricing are finalised.
A practical early review should answer:
What is actually being altered?
Is any structure or bracing affected?
Is plumbing or drainage changing?
Is the building footprint changing?
Is the exterior envelope being altered?
Does Schedule 1 clearly cover any part of the work?
Are there District Plan or resource-consent considerations?
Will restricted building work be involved?
Who needs to design or supervise the work?
Once those questions are answered, the project can be designed and priced around the correct pathway. It is much easier to deal with consent requirements on paper than halfway through construction.
Frequently asked questions
Do all home renovations need building consent?
No. Some lower-risk work can be carried out under exemptions in Schedule 1 of the Building Act. However, structural alterations, additions and many plumbing or drainage changes commonly require consent. The exact scope needs to be assessed before work starts.
Do I need consent to renovate a kitchen?
Not necessarily. Replacing cabinets, benchtops and finishes may not require building consent. New or significantly altered plumbing and drainage can change the requirements.
Do I need building consent to renovate a bathroom?
It depends on the work. Replacing finishes may be exempt, while new drains, certain new sanitary fixtures and tiled wet areas can require building consent.
Can I remove an internal wall without building consent?
Potentially, if the wall is genuinely non-structural and does not affect bracing, fire protection or another Building Code requirement. Structural or bracing walls require further assessment and will commonly require consent.
Can my renovation plans change after building consent is issued?
Yes, but changes need to be dealt with correctly. Minor changes may be approved as minor variations, while more significant changes require a formal amendment. Approval should be obtained before the changed work is carried out.
Planning a renovation in Wellington?
If you are thinking about renovating or extending a home in Porirua, Wellington, Lower Hutt, Upper Hutt or Kāpiti, Newport Construction can help you work through the practical construction side before the project gets too far down the design path.
That can include reviewing the existing house, identifying likely structural or consent issues, discussing the scope and helping establish a realistic route from concept through to construction.
Get in touch with Harvey to discuss your renovation and what you are trying to achieve.