A family building the largest passive house in the country could even be off-grid

At 660 square metres, this three-storey family home in Cockle Bay, Auckland is the largest certified passive house to be built in New Zealand – and possibly the Southern Hemisphere.

But it didn’t intend to be that big, admit owners Leonard and Sesame Lee, who say it looked much smaller “on paper”.

They started planning the six-bedroom house for their family of five, so the rooms could accommodate specific pieces of furniture – two of the bedrooms will be offices. And then, after Kim Veltman Architecture finished the design, the couple decided they needed to make it a passive house – and that’s how it developed.

Leonard Lee, pictured with his daughter Aria, builds New Zealand's largest passive house, with his wife Sesame, in Cockle Bay, Auckland.  It is a massif of 660 square meters.

Abigail Dougherty / Stuff

Leonard Lee, pictured with his daughter Aria, builds New Zealand’s largest passive house, with his wife Sesame, in Cockle Bay, Auckland. It is a massif of 660 square meters.

“Passive house requirements call for thicker walls (and lots of plants), which takes up space and makes rooms look smaller,” says Leonard Lee. “So everything was pushed to make sure the dimensions of the room would still be big enough.”

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Craft Homes builder Toby Tilsley doesn’t hide the project: “It’s absolutely the hardest thing I’ve ever done, because it wasn’t originally designed as a passive house. We had to make a lot of changes around thermal bridges for example. We’ve designed some great houses, but this is by far the biggest and most complicated we’ve worked on.

“It’s been a bit of a labor of love, but it’s a lot more rewarding (than a conventional build).”

The house overshadows the neighboring properties.  Photovoltaic panels on the roof will produce electricity which will be stored in batteries.  The windows are all triple glazed.

Abigail Dougherty / Stuff

The house overshadows the neighboring properties. Photovoltaic panels on the roof will produce electricity which will be stored in batteries. The windows are all triple glazed.

Toby Tilsley (left), owner of Craft Homes and project manager Nick Greer is committed to building high-performance homes, with projects scheduled through the end of 2024. The house is clad in thermo-modified pine Abodo, which will be covered every seven years.

Abigail Dougherty / Stuff

Toby Tilsley (left), owner of Craft Homes and project manager Nick Greer is committed to building high-performance homes, with projects scheduled through the end of 2024. The house is clad in thermo-modified pine Abodo, which will be covered every seven years.

Lee, who works in IT, undertook extensive research and consulted with passive house professionals. He describes the whole process as “a journey” and admits “there is an element of perfectionism in it”.

“When you buy into a philosophy of building something better, it’s not about making the norm. A Passive House is the evolution of how a house should be built, and this house is the evolution of the last one we built – it had to be better.

He attributes the current problem of houses that are too cold or damp, or too hot, to a failure of the people who set the standards: “Minimum standards are not enough.

And the couple have plenty of experience living in homes that aren’t up to snuff. Sesame grew up in a cold and moldy old villa in winter. And Lee himself lived on a leaky farmhouse, with no insulation in the roof, condensation in the windows, and mold on the curtains in the walls.

The three-story house sits on a section of just over 0.1 ha (quarter of an acre), which leaves enough space for a vegetable garden, greenhouse and orchard.

Abigail Dougherty / Stuff

The three-story house sits on a section of just over 0.1 ha (quarter of an acre), which leaves enough space for a vegetable garden, greenhouse and orchard.

“I’m a tech-savvy type of guy, and when you boil down a home to its first principles and ask what it’s for and why it exists, it comes down to people and what’s really important – being healthy, safe and comfortable.”

For this family, it’s also about sustainability and self-sufficiency – a Certified Passive House requires very little heating or cooling as the mechanically ventilated sealed interior keeps the house at an even temperature and low heat. year-round humidity. There are photovoltaic panels on the roof of the new construction, as well as batteries to store the electricity produced.

The solar power system allows the team to aim for the Passive House Plus standard (the second of three levels), as they will have renewable energy regeneration.

Rainwater is collected and there is a 600 liter hot water tank heated by an air to water heat pump which Lee says is “incredibly efficient”. A fully insulated hot water ring supply system will keep hot water circulating, so there is no need to wait for water to heat up when you turn on a tap, which saves water and saves energy.

Leonard Lee and Aria are standing in the main living area on the second level - the kitchen will be on the left.  The rimu flooring in this area was recycled from the original house on site.

Abigail Dougherty / Stuff

Leonard Lee and Aria are standing in the main living area on the second level – the kitchen will be on the left. The rimu flooring in this area was recycled from the original house on site.

“It’s similar to what you would find in a hotel or motel,” says Lee, admitting there are many “commercial” elements to the construction. There is an elevator, a huge plant room and a large cavity to accommodate plants that traverse all three levels.

The house requires two of the largest mechanical ventilation units. The adjoining pool house with indoor swimming pool has its own ventilation and sealing system.

Future-proof – “for the prepper in me”

For Lee, there is an element of durability. “There is a bit of a prepper in me. We could completely disconnect from the grid, if things go wrong,” he says. “It was designed so that we never had to leave the house (and the garden). We could literally cut the electrical wire to the house, and the water service, and we’d be fine. We are setting up a greenhouse, vegetable garden, chicken coop and orchard, so that we can grow our own food (the section is just over 0.1 ha – a quarter of an acre.)”

There will also be electric vehicle charging stations in the garages – Lee has been driving an electric vehicle for two years.

This is the billiard room at the back of the house.  It will house a swimming pool with swimming jets, and a balneotherapy pool.  It will have its own mechanical ventilation system and passive house certification.

Abigail Dougherty / Stuff

This is the billiard room at the back of the house. It will house a swimming pool with swimming jets, and a balneotherapy pool. It will have its own mechanical ventilation system and passive house certification.

The team recycled the rimu from the old house that once stood on the site. This is now the flooring for the main living area, which is on the second level to maximize views of the sea and site topography.

The two offices are also on this level, while the remaining bedrooms are on the third floor – the three girls, Aria, Hope and Gypsy each have their own walk-in closets, and there are en-suite bathrooms to several bedrooms. The floor on the upper level is made of Hebel aerated concrete – a strong but light material which reduces the thickness of the floor.

For the entire team working on the house, passive house certification takes on its full meaning. Project manager Nick Greer says he wouldn’t feel right building a standard house now: “You look at how other people are still building, and it almost makes you a little sick – they’re building something that isn’t not healthy and that doesn’t work, but they’re willing to spend hundreds of thousands of dollars on it.

Views are framed in every room.

Abigail Dougherty / Stuff

Views are framed in every room.

Tilsley is building his own certified passive house for his family in Raglan – meanwhile they live in a 37 square meter shed which is mechanically ventilated like a passive house. They didn’t have a cold or asthma.

Lee plans to share the family’s experience with others interested in building a passive house, saying people really need to step into a passive house to feel the difference in the living environment.

“We have seen all the Covids”

The Cockle Bay construction site has not been Covid-free, however. Self-isolations and lockdowns have hampered progress: “We saw all the Covids in this house,” says Tilsley. “Deadlines were stopped and started, which affected the schedule and price of the project. We had to change the price of a few elements to try to stay on budget – the price was fixed in 2018.”

The house is built on a slope, so the living room on the second level opens out onto flat ground.  The billiard room is on the right.

Abigail Dougherty / Stuff

The house is built on a slope, so the living room on the second level opens out onto flat ground. The billiard room is on the right.

Every day, a team of 10 to 12 people are on site, but this number has increased to 22 recently, as the interior finishes are being completed. The entire project is expected to be completed in July 2022. Lee says that removing all interruptions, construction took two years.

Compromise

Lee admits there were a few compromises along the way: “Some exterior doors aren’t as wide as we would have liked because Passive House doors have very thick frames. And the ceilings could have been higher, but again, the insulation eats up extra space.

“I originally wanted a massive north-facing roof to accommodate solar panels, but the design felt clunky. In the end, you achieve a balance between form and function.

But there’s also a lot to like about the design – Lee says Sesame planned the perfect laundry, and designer Mal Corboy designed a stunning kitchen that’s yet to be installed.

An aerial photo shows the extensive photovoltaic array on the roof.

Abigail Dougherty / Stuff

An aerial photo shows the extensive photovoltaic array on the roof.

Was he going to start all over again? “Yes, I would, but probably not on this scale.”

Lee’s advice for others: “It will be more expensive, so compromise accordingly. You have to educate yourself to know what you want and how to achieve it. Talk to passive house professionals early on and ask lots of questions.

“The devil is in the details, and there are a lot of details. Everything must be planned, designed and designed. Putting on something later will be expensive. Start small and try not to fall in love with the first (big) design – it’s harder to go back.

Thing will be back later in the year once construction is complete and the family is settled.