Thinking about building a granny flat? Here's what you need to know.
The granny flat building consent exemption allows certain new, single-storey, stand-alone dwellings up to 70 square metres to be built without a building consent, provided all exemption conditions are met and the work is carried out or supervised by a licensed building practitioner (LBP).
All building work under the exemption must comply with the New Zealand Building Code.
What is a granny flat and what is it called under the law?
A granny flat is a small, self-contained home that sits on the same property as the main house. It's designed to complement the main dwelling, and anyone can live in it - there's no requirement for them to be related to the people in the main house.
The name 'granny flat' changes depending on the legislation:
- Building Act: calls it a "Small Stand-alone Dwelling"
- Resource Management Act: calls it a "Detached Minor Residential Unit"
Both names refer to the same type of building.
One granny flat is permitted per site and must be in association with the principal residential unit.
Granny flats exemption guidance is available on building.govt.nz
To build a granny flat, you need to apply for a Project Information Memorandum (Small stand-alone dwelling) which will be issued within 10 working days. Applications are made online via: Objective Build.
Key conditions of the exemption
The dwelling must:
- Be new, stand-alone and single-storey
- Have a floor area of 70 square metres or less (including any internal garage)
- Be at least two metres away from any other residential building or legal boundary
- Be built using lightweight steel or timber framing and lightweight roof cladding
- Use wall claddings with a maximum weight of 220 kilograms per square metre
- Be connected to network utility operator (NUO) systems where available, or have compliant on-site systems
- Not contain a level-entry shower that requires a waterproof membrane
- Be designed and built (or supervised) by licensed building professionals
All plumbing, drainage, electrical and gas work must be carried out by appropriately licensed professionals and certified as required.
The build must be completed within two years of the PIM being issued - extensions may be granted by council before the two-year period lapses.
Homeowner responsibilities
Homeowners are responsible for:
- Applying for a PIM using Form 2AA under the Building (Forms) Regulations 2004
- Obtaining a PIM (Forms 2AAb and 2AAC under the Building (Forms) Regulation 2004) from council before starting any building work
- Making sure the granny flat meets all exemption conditions and complies with the Building Code
- Using licensed building professionals for all restricted building work
- Submitting all required documentation to council within 20 working days of completion
- Paying development contributions as notified in Form 3A. Please email developmentcontributions@tauranga.govt.nz or access the development contributions (DC) webpage if you require further information on DC requirements prior to applying for a PIM - Form 2AA
- Applying for a building consent if the exemption conditions are not met
- Non-compliance that may result in enforcement action, fines or prosecution.
Resource consent
- The building consent exemption operates alongside the Resource Management System
- In most cases, you won't need a resource consent under the Resource Management Act 1991 and National Environmental Standards (NES) for Minor Residential Units. Whether you need one or not depends on site-specific circumstances. Resource Management Regulations.
- Homeowners need to check planning rules and resource consent requirements separately.
Tauranga City Council has more lenient setback rules in a Residental Zone:
- 1m setback from side and rear boundaries
- 1.5m setback from front boundary
- Building Coverage is limited to 50% of total site for residential and 30% for Rural Residential
- All other permitted activities are the same as the National Environmental Standards (NES) and the Tauranga City Plan. For Planning advice, please contact the Duty Planner on 07 577 7000.
Other approvals
- Other approvals will be needed for network utility connections and vehicle crossings
- Water supply, plumbing and drainage must connect to an existing network utility operator (NUO). Homeowners will need to apply online for a Service Connection (SCA) before completing these connections
- If NUO services aren't available or lack capacity, you can use an on-site system. If On-Site Effluent Treatment (OSET) is required for wastewater, a regional consent will likely be required. If you have any queries about this, please contact Bay of Plenty Regional Council on 0800 884 880 or email permittedactivitymonitor@boprc.govt.nz
After completion
- Homeowners must provide all required documentation to council within 20 working days of completion.
- Licensed Building Practitioners are required to provide the Record(s) of Work (Form 6A) to both the council and homeowner
- Councils add these records to the property file and LIM, but do not issue a Code Compliance Certificate for exempt granny flats
- Councils may take enforcement action if notified of non-compliance or if the building is unsafe or insanitary
- Development contributions must be paid by the homeowner within 20 working days of completion if required
- Councils are not required to monitor progress or remind homeowners of deadlines – responsibility rests with the homeowner.
PIM expiry and development costs
The PIM is valid for two years. If it expires and you haven’t applied for an extension, the work will no longer comply with the exemption, and you will need to apply for a Certificate of Acceptance (COA). Council’s Fees and Charges and development contribution fees will be charged in line with the operative DC Policy at the time of lodgement of the COA.