Researchers Launch Free Granny Flat Plans to Aid Families

Homeowners in New Zealand will soon have access to free architectural plans designed for granny flats, thanks to a new initiative from researchers at Auckland University. The plans are part of a project funded by Branz, New Zealand’s independent building research organization, which has allocated $220,000 for this 18-month endeavor. This initiative coincides with the implementation of the Building and Construction (Small Stand-alone Dwellings) Amendment Act 2025, which takes effect on January 15, 2025.

Led by Professor Anthony Hōete, who is of Ngāti Awa descent, the project aims to create open-source plans for buildings up to 70 square metres. Hōete emphasizes that these designs will benefit many families, particularly those looking to establish intergenerational living arrangements. He notes, “They could be for kaumātua [respected elders] or transitional housing. Maybe the kids want a couple of extra rooms outside,” addressing the growing need for additional living space.

The initial phase of the research will involve analyzing 1,000 different properties to better understand various living conditions and lot configurations. Following this, the team plans to create a range of designs, complete with full sets of drawings, documentation, and specifications, which homeowners can download at no cost. This collaborative effort includes a partnership with Context Architects, known for their work in affordable housing through Kāinga Ora.

Hōete highlights the importance of affordability, aesthetic appeal, and sustainability in the designs. The estimated construction cost ranges from $3,500 to $4,000 per square metre, totaling under $300,000 for a complete unit. Some designs will also prioritize universal accessibility, ensuring that they accommodate individuals with disabilities, including elderly residents.

“This project is exciting,” Hōete says, expressing optimism about its timing. “We’ve come out of a difficult couple of years economically. This will offer people tangible options for empowerment. They can choose from a suite of designs, find a builder, and make it happen.”

The granny flat initiative is one of 22 new projects benefiting from a total of $11.5 million in funding from the Building Research Levy. This levy, set at 0.1% of all building consents exceeding $20,000, is assessed annually by an independent group to support projects that aim to improve building quality, reduce costs, and enhance sustainability across New Zealand.

Other notable projects funded in this round include:
– **Whakamaru i te Rangatahi**: Addressing housing solutions for rangatahi and whānau, led by the Pūrangakura Māori and Indigenous Research Centre.
– **Architecture for all**: Focused on building equity through AI and whānau-centered design, by Te Wānanga o Aotearoa.
– **Retrofitting homes**: Aiming to lower energy bills and enhance comfort, by the Centre for Research Evaluation and Social Assessment (CRESA).

Understanding the Granny Flat Legislation is essential for homeowners interested in this new opportunity. The legislation, officially titled the Building and Construction (Small Stand-alone Dwellings) Amendment Act 2025, was passed by Parliament in October 2025. Key points include:

1. The building consent exemption for granny flats will commence on January 15.
2. The exemption applies to self-contained dwellings up to 70 square metres.
3. Designs must comply with the Building Code and be supervised by a licensed building professional (LBP).
4. Local councils must be notified before and after construction, and homeowners are responsible for applying for a Project Information Memorandum (PIM) and paying infrastructure contributions.
5. The legislation aims to boost housing supply, with projections estimating around 13,000 granny flats built over the next decade.

As New Zealand grapples with housing shortages, this initiative presents a practical solution, empowering homeowners to enhance their living situations while contributing to the broader housing landscape.