The future of social housing is healthy and sustainable
Kāinga Ora is the New Zealand Government's urban developer and public housing landlord, providing accommodation for some 187,000 Kiwis. The Crown entity aspires to be an industry leader in transitioning the property sector to climate-friendly construction practices.
Ngā Kāinga Anamata (meaning “Homes of the Future” in te reo Māori) is one of several initiatives under its Carbon Neutral Housing Programme. Ngā Kāinga Anamata is a sustainability-innovation pilot programme seeking to resolve many underlying problems with New Zealand’s housing sector including construction sector productivity, energy hardship, sick building syndrome, and climate change mitigation.
The programme involves the design of five almost identical three-level walk-up buildings in Glendowie, in inner East Auckland. Each building is to be constructed using a different building structural system (precast concrete, light timber frame, cross-laminated timber, light gauge steel frame, hybrid light timber and CLT) and to the following performance standards:
The Passive House Standard to achieve the proposed 2030 operational efficiency targets MBIE’s Building for Climate Change Programme
Net Zero Energy status via a roof top photovoltaic array
Where possible, reduced lifecycle embodied carbon through lower carbon and long-lived materials
Lifecycle carbon impacts calculated and reported against the BRANZ/Massey University 1.5°C science-based target/budget for new residential buildings specific to New Zealand
Site wide, other holistic sustainability outcomes to enhance bio-diversity and minimise deconstruction and construction waste are proposed
Ngā Kāinga Anamata aims to understand the holistic cost and benefits by testing the design, construction, as-built and post-occupancy performance of low carbon public housing. It also considers commercial aspects such as cost, time, quality, productivity, and supply chain that will inform Kāinga Ora of industry capability and readiness. This programme is currently 90 per cent through design, with construction to begin early 2022 and completion expected 2024.
Benefits for residents and the environment
The new homes will benefit both residents and the environment, with the Passive House certification expected to result in lower energy bills while providing a healthy and comfortable living environment. Once tenanted, Kāinga Ora will monitor the energy consumption of each walk-up, to understand the impact of the different structural systems on energy use and the value of the Passive House and Homestar Ratings.
Aurecon has been engaged as the Passive House Designer of the project and is delivering building services (mechanical, electrical, hydraulic engineering and fire protection) and façade engineering peer review across all five walk-ups, as well as energy performance modelling. Bespoke mechanical solutions are needed for the buildings to achieve the Passive House certification, requiring extensive collaboration with the project architect.
Passive House is still a relatively new concept in New Zealand and Kāinga Ora should be commended for their ambition in delivering a development using the framework. Originating in Germany, Passive House is recognised internationally as a best practice benchmark for low energy use, indoor environmental quality, and health performance, especially when applied to social housing.