In a first, trade students at One Tree Hill College, a co-educational state secondary school in Penrose, are carrying out a deep retrofit on an ex-state house as part of their building apprenticeships.
The house, typical of 70,000 homes around Aotearoa, was relocated from Māngere East where Kāinga Ora has a major redevelopment. The students are upgrading it into a healthy, dry home, aiming to achieve New Zealand Green Building Council (NZGBC) Homestar 7 accreditation.
The 65 students enrolled in BCITO’s level 2 and level 3 trade programmes at the college are being supervised by licensed builder Paul Williams and Head of Trade Charlotte McKeon. The students work on the house during the school day and can contribute on Saturdays and during the holidays.
Kāinga Ora and BCITO involved
Kāinga Ora is a partner in the project, and BCITO has been engaged, providing training advisors that support the different trades working on the house.
While the priority is training students to become apprentices, working to Homestar means they learn practices that exceed the Building Code and about new technologies. The focus is on materials, recycling and energy consumption.
Energy efficiency challenge
Before the project started, NZGBC warned that exceeding the requirements of clause H1 Energy efficiency would be the first hurdle and achieving a tight thermal envelope would be challenging.
Homestar designer Sarah Elicker has used NZGBC’s Energy and Carbon Calculator for Homes (ECCHO) tool to calculate thermal comfort, energy and carbon emissions. Timber used in the structural walls has been reduced by 20% by removing all nogs, and the walls are double insulated and incorporate a layer of ply for bracing. Those wanting to become electricians have wired a smart panel that will reduce electricity costs by 10–25%.
Additionally, an interior decorator is working with students interested in kitchen and bathroom design, and four students are on work placements at the factory where windows and doors for the home are being manufactured. Their work is supported by former students finishing apprenticeships at the factory.
To support cross-curriculum learning at One Tree Hill College, students studying other disciplines have visited the house. For example, level 1 history students studying state housing in Aotearoa took a first-hand look at the original construction and learned about the challenges of heating older homes.
The house will be auctioned at the end of the year - fully furnished and staged. The buyer will relocate the fully furnished home to the site of their choice and proceeds will fund another ex-Kāinga Ora home for students to upgrade in 2025.