Free Granny Flat Plans Launch to Aid Intergenerational Living

Homeowners in New Zealand can now access free architectural plans for granny flats, following the implementation of new legislation. The initiative, which takes effect today, aims to support families seeking intergenerational living solutions. Funded by Branz, New Zealand’s independent building research organization, the project is led by Professor Anthony Hōete from Auckland University.

The grant of $220,000 will finance an 18-month research project focused on developing open-source plans for buildings up to 70 square metres. Professor Hōete, of Ngāti Awa descent, emphasizes the potential benefits for various living arrangements, including transitional housing and accommodations for respected elders, known as kaumātua. He notes that these structures may help alleviate overcrowding in existing homes.

Research will begin with an examination of 1,000 properties to understand current living conditions. The team plans to create a range of designs, complete with full documentation, that homeowners can download at no cost. Partnering with Context Architects, known for their work on affordable housing, the aim is to produce aesthetically pleasing and sustainable homes. The estimated build cost ranges from $3,500 to $4,000 per square metre, totaling under $300,000 for a complete unit.

Some designs will prioritize universal accessibility, catering to individuals with disabilities and the elderly. Hōete expressed enthusiasm for the project, stating, “This is going to give people tangible options where they can be a little bit self-empowered.” He believes that providing a selection of designs can empower families to find builders and construct suitable living spaces.

The granny flat initiative is part of a broader funding program that allocates $11.5 million from the Building Research Levy to various projects. This levy, set at 0.1% of all building consents exceeding $20,000, is used to finance practical solutions aimed at improving housing quality and sustainability in New Zealand.

Other significant projects funded in this round include initiatives like Whakamaru i te Rangatahi, which focuses on housing solutions for young people and families, and various programs aimed at enhancing energy efficiency and resilience in homes.

The new legislation, formally known as the Building and Construction (Small Stand-alone Dwellings) Amendment Act 2025, was passed by Parliament in October 2025. It allows homeowners to construct qualifying granny flats without the need for a standard building consent, effective from January 15, 2025. The exemption applies to self-contained dwellings up to 70 square metres and includes specific design requirements, as well as the need for supervision by a licensed building professional.

Local councils must still be informed before and after construction begins, and homeowners are required to apply for a Project Information Memorandum (PIM) and pay any necessary infrastructure contributions. This legislative change aims to increase housing supply, with expectations of approximately 13,000 granny flats being built over the next decade, aligning with the goals set forth in the National–New Zealand First coalition agreement.

Overall, the initiative represents a significant step towards enhancing housing options in New Zealand, particularly for families seeking to integrate intergenerational living arrangements. Through the combination of accessible design plans and supportive legislation, homeowners are better equipped to create functional and sustainable living spaces.