From the moment Rob and Hayley Larman moved into their architecturally-designed house it felt like home.
“I think it’s because we’ve been so invested right from the design phase through the build. It’s awesome,” says Rob.
“It’s a really personal thing,” says Hayley. “You want to make sure the money you are investing is right.”
During the design process they asked Kane DeRaat, their architectural designer from Davista, to make some changes.
“We took Rob and Hayley’s feedback, went back to the site and skewed the wings to face the views better,” says Kane. “Repositioned it, made subtle changes, gave it a slight trim in area and lowered the stud height slightly.”
“We had to re-evaluate what we wanted,” says Hayley. “Our frustration was that it was going to cost more than what we were prepared to spend but this was more to do with us, as we realised we had been a little bit unrealistic.”
They continually reassessed their finances through the build, with Justin Horler, their builder from JBH Building, helping Hayley set up a spreadsheet to track everything.
“I knew what costs were coming in,” says Hayley. “We shopped around for the best prices.
“Justin has been really open with us about costs, which really helped in terms of figuring out what we could spend. Obviously we didn’t want to put ourselves in a huge lot of debt and not be able to enjoy the house.”
From the start their owner-builder relationship was one of mutual trust and respect.
“Having a good working relationship is really important,” says Justin. “Hayley and Rob put a lot of trust in me; this is their future and mortgage. Being able to communicate directly with clients on the spot means that prompt decisions will save a lot of time. With a running budget throughout the build, if a client wants to make a change on material we can get figures together, quickly communicate and make those changes.”
One of the elements that Rob had liked about JBH Building was the company’s use of Ambionse ICF building blocks. These provide the framework for concrete walls, as well as providing the wall insulation.
“Ambionse allows you to create homes that are more energy-efficient, stronger, more sound-resistant, and more environmentally-sustainable than if you use timber framing,” says Justin. “Also Ambionse is faster, lighter, cheaper and warmer than conventional masonry.”
The concrete was poured into the polystyrene, which was first boxed and braced. Left in place, the polystyrene becomes the insulation and cladding.
“It’s strong and robust,” says Justin. “It’s more than double the insulation value of the standard conventional build but it’s efficient. It takes a week, to a week and a half to get the walls up, but in that time we do all the fixings, framing, cladding and insulation. So there’s four weeks’ worth done in a week and a half. This added efficiency in the build saves on labour, and that saving gets passed on to the client.”
The results speak for themselves. It was a cold day when we arrived to view Rob and Hayley’s completed home. Hayley came to the door barefoot, wearing a sleeveless mini, clearly enjoying the internal warmth.
“If you’ve got the right site orientation to maximise the solar gain, the home will heat itself,” says Justin. “With ICF the temperature will only fluctuate a few degrees, rather than more than 10 degrees fluctuation experienced in timber homes.”
“Kane got it perfectly right with how he placed the house on the site,” says Hayley. “As the winter sun comes across, the whole house captures it.”
We’re led through the entrance hall into the main living area which opens up to a stunning view of the Tauranga harbour.
The kitchen, by Prestige Benchtops, continues the black and wood theme, simple and sleek and designed for easy flow. Hayley’s upcycled bar stools, with legs painted black complement the new dining table and chairs.
The concrete floor, polished by Grind King, perfectly underpins the overall white-on-white theme, with black highlights picked up in the floor’s pebble flecks. The concrete slab base and edge has also been completely insulated, generating a high-performing thermal envelope underfoot. Justin calls it “solar gain on the thermal mass”.
“You can lose 60 per cent of your heat through the floor,” says Justin. “So we wrap the whole house with a warm blanket.”
The up-scaled large windows use low E glass filled with argon gas, capturing and hold the sun’s warmth. This double glazing, along with the wrapped concrete flooring, helps lift the performance of this energy-efficient home. Timber trim was removed from around the windows with plaster board returned into the window reveal. This keeps a sharp, clean line around the view capture.
High attention to detail is reflected in the builder’s oak stud features.
“We set up a mitre jig to drill the holes in the stud in the perfect position every time so when it was plugged they’re all consistent,” says Justin. “It makes the overall finish a lot better.”
Outside the front door the builders also perfectly aligned the cedar battens from corner to corner, with the cedar’s knot feature creating added interest, setting the modern, industrial-looking house alive.
The deck, made of garapa – king of hardwood decking timbers and an all-round performer – has a golden to brown colour which will weather nicely to a silver patina. Well-protected from the wind, it is flush with the lawn, and overlooks the newly planted 200 native plants along the east flanking bank.