Plan a granny flat: step-by-step guide
Last updated: 3 July 2026
This guide provides step-by-step instructions and process stages for planning granny flats built using the building consent exemption. It clarifies roles and responsibilities for key parties and explains important steps and considerations.
Step 1: homeowner decides to build a granny flat
A homeowner decides to build a granny flat (small standalone dwelling) on their property. They research the building consent and granny flats building consent exemption pathways and begin to gather information about their site.
Step 2: homeowner preliminary investigation
The homeowner researches the Resource Management Act (RMA) requirements for their property by checking with the Ministry for the Environment (MfE) and their local council to understand the National Environmental Standard for Detached Minor Residential Units (NES-DMRU) and other permitted development rights for their site.
National environmental standards for detached minor residential units [PDF 253KB] – environment.govt.nz
Step 3: homeowner does their due diligence
The homeowner checks if development contributions (DCs) are payable. The specific amount varies depending on the location and what is being built, so they check with the local council what the amount is likely to be for their granny flat.
The homeowner uses the due diligence checklist to check that they have carried out thorough research.
- Due diligence checklist [PDF 357KB]
- Due diligence checklist [PDF 358KB, simplified Chinese]:祖母房豁免：业主尽职调查清单
Step 4: LBP designer is selected
The homeowner visits the Licensed Building Practitioner (LBP) website to find an LBP designer or check that their chosen designer is an LBP. They meet with them to discuss what they want to build.
Search the LBP register for a designer – lbp.govt.nz
A designer, as referenced in this guidance, is an LBP. They have a design licence or equivalent qualification such as a Registered Architect, or CPEng Engineer.
Step 5: LBP designer is contracted
The LBP designer provides the homeowner with a contract, who gets it checked by their lawyer and both parties sign the contract.
Step 6: granny flats exemption conditions are investigated
The homeowner and LBP designer discuss the granny flat exemption conditions, technical requirements and process. They review the information that they have gathered about the site.
The homeowner and designer discuss whether the proposed build will meet the exemption conditions. The homeowner and designer are confident that the proposal will fit fully within the scope of the granny flats exemption.
- Building design conditions checklist [PDF 350KB]
- Building design conditions checklist [PDF 344KB, simplified Chinese]: 祖母房豁免：建筑设计条件清单
- Comparison of exempt and consented building types [PDF 1MB]
Compare small building types to choose the right exemption or consent pathway.
Step 7: cost/benefit comparison
The homeowner compares the costs and benefits of using the granny flats exemption against obtaining a building consent for their project.
The LBP designer helps them understand the roles and responsibilities of each party involved, and the risks and liabilities of using the granny flats exemption pathway.
Step 8: granny flats exemption pathway is confirmed
The homeowner and LBP designer discuss what pathway is most appropriate for the project. The homeowner decides to build a granny flat using the exemption pathway.
Step 9: preliminary design
The LBP designer prepares preliminary design plans for the granny flat. They ensure the plans show how the granny flat complies with the exemption.
The homeowner approves the design and is ready to apply for a PIM.