Bader Ventura

Bader Ventura is a multi-award-winning, Passive House certified public housing development in Māngere, delivered for Kāinga Ora — Homes and Communities. As Australasia's first government-funded Passive House project, it sets a new benchmark for low-carbon, climate-safe housing in New Zealand.

The development comprises 18 warm, dry apartments across three-storey walk-ups — 12 three-bedroom and 6 two-bedroom homes — with 2.7-metre high ceilings over living spaces. The Passive House standard delivers superior thermal comfort and indoor air quality through a high-performance airtight thermal envelope, maintaining an average year-round internal temperature of 20–25°C with very low energy use.

Walls and roof feature around 1.5 times higher insulation than standard construction, combined with smarter framing that eliminates thermal bridging. Compared to standard 6 Homestar v4 homes, Bader Ventura reduces operational energy carbon by 35% and space heating electricity by approximately 62% — with average heating energy use of less than 15kWh/m²/year, an annual power bill of around $360 versus $700, and heating and cooling costing around $1.00 per day.

The project pioneered several construction innovations in New Zealand. Extremely weak soil conditions were addressed with stone column ground improvement and reinforced gravel rafts — a non-vibration method used for the first time in Auckland — eliminating the need for an expensive pile foundation. Precast reinforced concrete foundations, among the first used in an apartment complex in New Zealand, were developed in collaboration with the builder to eliminate foundation formwork and increase construction efficiency.

The wall system uses Thermomass insulated precast concrete panels, with Neocrete low-carbon concrete saving over 14 tonnes of cement and 9 tonnes of carbon — the equivalent carbon sequestered by 170 twenty-year-old native trees. Free-standing balconies were cast in precast concrete with castellation to reduce thermal bridging connectors, while thermally broken connections were used for the breezeways to minimise thermal loss.

BIM modelling and LOD400 detailing enabled off-site manufacturing with high precision, allowing the contractor to price the project accurately at building consent stage. The development achieved both a 7 Homestar v5 rating and an 8 Homestar v4 rating, and meets MBIE's Building for Climate Change 2035 'final' thermal performance cap 12 years ahead of schedule.

The design also carefully considered the changing needs of New Zealanders, including wheelchair-friendly bathroom and kitchen areas. From the first precast panel to handover, the main construction duration was 11 months.