Don’t get caught out assuming a 70 m² granny flat means no Council fees in New Zealand
If you’re planning a granny flat in New Zealand, understanding the difference between Building Consent, Resource Consent, and Development Contributions can save you from turning a “small” project into an unexpectedly expensive one.
As an Architectural Designer working in New Zealand, I’m seeing growing confusion around recent announcements — and some costly assumptions being made.
There’s been a lot of discussion recently in New Zealand about proposed changes to granny flat rules, including statements suggesting that small standalone dwellings may no longer need Building Consent. Some people have taken this to mean they won’t need to pay the Council anything at all.
That assumption is risky — and in some cases, very costly.
While the intention of the proposed changes is to reduce red tape and building costs in New Zealand, they do not remove all Council approvals or fees.
What is being proposed is an exemption from Building Consent for qualifying granny flats — not a blanket exemption from Council requirements.
In the New Zealand planning system, Building Consent is only one of several approvals that may apply to a project.
Building Consent (New Zealand)
Building Consent is the approval process that demonstrates compliance with the New Zealand Building Act through the New Zealand Building Code.
It focuses on how a building is designed and constructed.
Resource Consent (New Zealand)
Resource Consent is entirely separate. It deals with how a development affects:
The site
Neighbouring properties
The wider environment
Resource Consent is governed by the Resource Management Act 1991 (RMA) and administered through your local District or City Plan.\
As at 1 January 2026, it’s important to note that:
The proposed granny flat exemption legislation has not yet been passed
It cannot be applied retrospectively to previously unconsented granny-flat-type dwellings
Development Contributions in New Zealand (often missed entirely)
Development Contributions are another layer again — and one that is frequently overlooked.
In New Zealand, Councils charge Development Contributions for:
Infill development
Additional dwellings added to a site
These contributions help fund infrastructure upgrades such as:
Water supply
Wastewater
Stormwater
Transport and community facilities
As more dwellings are added to existing neighbourhoods, infrastructure must keep up. Without this, we risk reduced water pressure, overloaded sewer systems, and broader neighbourhood issues.
What this could look like in the real world (New Zealand context)
No Building Consent (future proposed option)
Even if Building Consent is not required under the proposed rules:
You would still need Licensed Building Practitioners (LBPs) for both design and construction
Professional design and construction fees still apply
Insurance requirements for LBPs in New Zealand are tightening, with homeowner insurance discussions still evolving
For context, a typical Building Consent in New Zealand for a single story dwelling currently costs roughly between $5,000 and $10,000, including:
Council application and processing fees
Site inspections by Council officers
Resource Consent costs
Even where a granny flat qualifies for the proposed Building Consent exemption, it must still comply with:
District Plan rules
Planning controls such as site coverage, setbacks, height, density, and servicing requirements
If a project does not comply, a Resource Consent is required. In New Zealand, these can cost $10,000–$20,000 or more, including:
Council fees
Planning and technical consultant reports
Additional architectural design work
Development Contributions
Development Contributions are independent of Building Consent costs.
Indicative figures in parts of New Zealand (varying by Council) are:
One-bedroom ancillary dwelling: approximately $15,000
Two-bedroom dwelling: approximately $23,000
These charges apply whether or not Building Consent is required.
If you’re planning a granny flat or ancillary dwelling in New Zealand, it’s essential to understand the full regulatory and cost picture, not just the headline.
Getting early, site-specific advice from an Architectural Designer can help you understand:
Which consents apply to your site
What your real project costs are likely to be
Whether the project still stacks up financially
This is exactly what I cover in a Design Consultation — helping New Zealand homeowners understand where their project is heading before they commit time, money, or energy.
If you’d like to talk it through, I’m always happy to have an initial chat and help you make sense of what your New Zealand site and idea might really involve.