Building up to Net-Zero
Some homes already make as much energy as they use
The spacious home in Guelph’s toney Heritage Lake Estates has all the bells and whistles you’d expect in a $6.5-million, luxury residence: seven bedrooms, eight bathrooms, 16-foot ceilings, high-end appliances, a wine room, home gym, theatre room and games room.
Outdoors, there are covered and open patios, an al fresco kitchen, limestone facade and walkways, feature walls and a concrete pool.
Built by Timberworx Custom Homes and completed in 2017, the total 9,200-sq.-ft. house has it all — except for costly energy bills.
As Canada’s first luxury certified Net-Zero home, it produces at least as much energy as it consumes, thanks in part to the expansive array of rooftop solar panels. To qualify as Net-Zero, it also includes enhanced insulation and air tightness, triple-glazed windows, superior indoor air quality, water-saving features and energy-efficient lighting.
This is the future of homebuilding. It’s a timely look ahead —Tuesday, June 5 is World Environment Day. As well, the provincial government requires that, by 2030, all new houses be constructed as Net Zero.
Ayear ago, the Canadian Homebuilders Association launched a labelling program to provide a system to recognize Net Zero and Net-Zero Ready homes. (NetZero Ready homes lack only the solar panels).
Fully Net-Zero homes are still rare in Canada and most are modest in size.
They have their challenges, such the high cost of some components, and insufficient hydro infrastructure that limits how many homes can be hooked up to the grid.
With his Heritage Lake Estates house, Shawn Marsh, president of Timberworx, wanted to prove that someone could have a large, luxury home yet still be a good eco-citizen. And he wanted to build a house that didn’t sacrifice curb appeal or features, such as 19-foot glass curtain walls.
“Initially, my designers said it couldn’t be done, but after a lot of ‘Why nots?’ they engineered a design that met all the Net-Zero criteria,” Marsh says.
“We didn’t want to build a one-off glass castle. We wanted to be able to integrate the technology and offer it to our clientele.”
He and wife Eve Claxton, who had a major hand in designing the house, moved into it last summer to gain first-hand insights and work out any issues since Marsh plans to build two Net-Zero estate subdivisions. He is installing a comprehensive monitoring system on every circuit in the home to show clients where the hydro goes and what the consumption is.
“My wife made it clear she did not want to see any solar panels,” says Marsh, who plans to sell the house later this year.
“So we designed a commercial-style flat roof, complete with parapet walls to hide the panels. This had the added advantage of allowing us to disregard home orientation. The home faces north and all our panels face south.”
Timberworx became the first builder to install the Tesla Powerwall 2 as its battery storage system for energy collected from the panels, and partnered with Panasonic for the solar component. The three Powerwalls store excess solar power and the system also sends power to the hydro grid for a rebate under Ontario’s microFIT program.
“The Powerwall 2 design and performance have been flawless,” Marsh says. “The Tesla app, which is quite beautiful, is addictive. One finds oneself constantly checking today’s (solar) production and consumption.
“The added benefit is you can double-check if you have turned off everything not being used in your home.”
Heating and cooling equip- ment is in the early stages of development for Net-Zero homes, Marsh says, and that was problematic; the reduced loads created by ultra-efficient insulation and windows calls for smaller mechanisms. Airsource heat pumps are used to heat and cool Marsh’s Net-Zero house.
There are other Net-Zero homes in the province, with more on the horizon. A few other examples. Country custom: Marc Fortier, 57, and his wife moved into a custom-built, 3,600-sq.-ft., two-storey home on a 68-acre rural property in Durham Region last year. The home, built by Steve Snider Construction, is currently Net-Zero Ready, with superior insulation, windows and doors and a groundsource heating and cooling system.
This year, they plan to add solar panels and make it fully Net Zero, taking advantage of the provincial government’s upcoming solar power installation incentive — pending the outcome of the election on Thursday. Fortier says they also plan to join Hydro One’s net metering program that will see them accumulate credits in the summer when feeding the grid, and use those credits in the winter. Small-town solar: When newly retired couple Karen and Wayne decided to sell their Newmarket home and downsize to a quieter community, they were also looking to scale back on utility bills.
Wayne, an engineer, started investigating and found certified Net-Zero homebuilder Doug Tarry Homes in Strathroy, a small town west of London. The couple customized one of Tarry’s plans and added a full solar system to their new 1,945-sq.-ft. bungalow they moved into in April 2017. It has a 10kW system with 22 solar panels on the roof, air-source heat pumps and a gas-powered generator that automatically starts during a power outage. Their solar array feeds into the grid and theirs was the first home the local hydro company, Entegrus Powerlines, hooked into its system. “We estimate it cost us $60,000 to go Net Zero, but we figured if we were going to build a new home, we’d put it in initially rather than tearing things apart later on,” Karen says. “Our hydro bill is $33 (plus about $30 a month for the transmission line to the grid), and our gas bill is $22. It’s been a very good move for us and good savings.”
(Doug Tarry Homes says the average cost is $7,500 to $10,000 to upgrade one of its new houses to Net-Zero Ready and another $30,000 to $40,000 for full Net Zero.)
Ryerson University, in conjunction with Union Gas, has been monitoring the house since last fall to track how the systems work and how much energy it generates and uses. Zero House: Created by Ryerson students for last fall’s EDIT — Expo for Design, Innovation and Technology — Zero House is a modular home that can be adapted as a single home for infill lots or used as a stacked townhouse.
It was built in partnership between EcoStudio, a research cluster founded by a trio of Ryerson professors, and the Endeavour Centre, a Peterborough not-for-profit agency that teaches and promotes sustainable design and construction.
The 1,100-sq.-ft. house was bought and reconstructed on the new owner’s land in Clarksburg, west of Collingwood. Its orientation and construction methods maximize passive solar heating and ventilation — straw bales and cellulose fibre provide dense insulation; it has high-tech breathable and weatherproof interior and exterior membranes; solar panels line the roof. The structure is unique among Net-Zero homes in that it also achieved zero embodied carbon emissions, zero toxins and zero construction waste. Its ash wood flooring was made from trees felled due to emerald ash borer infestation. By using organic materials, like wood and straw bales, the home “sequesters” 25 metric tonnes of carbon where a similar-sized conventional home’s materials would emit 45 tonnes into the atmosphere.
It is tied into the hydro grid and was one of the last homes accepted into Ontario’s microFIT program and earn credits for feeding energy into the grid, says Chris Magwood executive director of the Endeavour Centre
“The house isn’t certified Net Zero, but the Ryerson team did the energy modelling that indicated we would meet our NetZero energy-use target,” Magwood says.