Energy efficiency and aesthetics merge

An exciting collaboration between two high-calibre construction and architectural teams has delivered a stunning high-performance home on New Plymouth’s Beach Street, combining contemporary design with technical excellence and energy efficiency.
The project was the result of a partnership between Slate Construction and Imagine Architecture, two firms with complementary expertise and a shared passion for building homes that perform as beautifully as they look.
Slate brand and marketing manager Heinrich Swartz says although the home is not a certified Passive House, it was designed with a strong focus on energy performance and sustainability with Imagine Architecture’s Tony Biesiek, a certified Passive House designer, leading the design.
The result is a home that delivers exceptional comfort, thermal efficiency, and environmental responsiveness.
“The clients were really clear on their vision – they wanted a warm, comfortable, and efficient home that would save them on energy costs in the long term,” Heinrich says.
“They’ve moved in now and absolutely love it. It’s a high-quality, high-performance build, and we think it’s a great way forward for residential construction.”
The home features airtight construction, a mechanical heat recovery ventilation system, SIPs construction by Formance, high levels of insulation, and uPVC windows and doors.
Natural ply ceilings, extensive timber finishes, and feature glulam beams add warmth and character, while large panes of glass bring in light and views of the landscaped section.
Tony Biesiek, director of Imagine Architecture, says the design brief was both exciting and challenging, with the clients downsizing from a lifestyle block and needing to maximise space on a smaller section.
“We hugged the house back to the southern boundary so we could open up the north side for outdoor living,” Tony says. “We also had to design around a baby grand piano and significant artwork. The piano is now the centrepiece of the living space, which is exactly where something that beautiful should be.”
Tony says his practice specialises in high-performance, sustainable design, with a focus on combining comfort, efficiency, and aesthetics.
The Beach Street home showcases that philosophy, with clever design moves like a large north-facing picture window overlooking the garden. Above it, a sheltered aperture has been created for the clients to grow a tree through, strengthening the connection between house and garden.

“On one of their first days moving in, the client emailed me to say the doors had been opening and closing all day, but the temperature inside stayed at 16.9 degrees with no heating,” Tony says. “That really shows the level of comfort and energy efficiency that has been achieved.”
For Slate, the project demonstrates the value of collaboration between construction and design. The company’s team brought their technical expertise to resolve the challenges of building a high-performance home, including complex negative details and the integration of mechanical systems.
“We worked closely with Imagine Architecture to ensure the design intent was met while also managing cost and constructability,” Heinrich says. “There was a lot of value engineering, and we made sure everything came in on budget. High-end residential projects are often open-ended, but we prefer to offer our clients fixed-price contracts, which is unusual at this level.”


Slate was formed through the merger of BuildtechNZ and Fortyone Architecture, a partnership born from years of successful collaboration.
The company now delivers both design and construction, with a focus on seamless integration and quality outcomes.
Heinrich says the Beach Street project is the third high-performance home Slate has built, and he expects more to follow.
“Mechanical ventilation and airtight construction make such a difference to comfort and liveability,” he says. “We’re excited to keep building in this energy-efficient space and to partner with more firms like Imagine Architecture to deliver homes that are both beautiful and resilient.”

The home features airtight construction, a mechanical heat recovery ventilation system, SIPs construction by Formance, high levels of insulation, and uPVC windows and doors.
