|September 19, 2011|
Part office building, part power plant
|Imagine: An office building with no carbon footprint. |
It may seem like a tall order, but that's the plan for the GreenLife Business Centre in Milton, Ont., scheduled to begin construction in February. By combining leading-edge energy conservation techniques and a huge solar array, the building will likely be Canada's first "net positive" office building, which means it will produce more energy than it consumes.
"There will be times, particularly at night, when we'll be taking energy from the grid, but in the daytime we'll be putting it back," said Dave De Sylva, a partner in Markham, Ont.-based Del Ridge Homes, the building's developer. "On balance, we'll be putting back a lot more than we'll be using."
The four-storey building will have 32,000 square feet of office space and require 137,500 kilowatt-hours of energy a year -- 22 per cent of what a conventional building of the same size would use, Mr. De Sylva says.
The structure will be heated and cooled geothermically and built with insulated concrete forms enhanced with an extra layer of extruded polystyrene. It will have triple-glazed, gas-filled, thermally "broken" windows. On top of this, the building will produce about 328,000 kwh of energy a year from its photo-voltaic solar array. Mr. De Sylva estimates that 190,500 kwh of excess "clean" energy will go back into the power grid.
From Mr. De Sylva's perspective, the construction industry is reluctant to undertake projects like this one because it is wary of change. "It's so easy to repeat what you did yesterday, and the formula seems to put money in your bank account," he said. "Also, it's new territory, and when it's new territory people are afraid they might fail."
But is it really the fear of failure that prevents this kind of project from being built in Canada? Only a handful of commercial building projects designated "net zero" -- meaning they produce as much energy as they consume -- are being built across the country.
One of the big issues is scale, says Stephen Pope, a sustainable-building design specialist for Natural Resources Canada. It's possible for a four- to seven-storey building such as the GreenLife Business Centre to attain net-zero status, but office buildings in big cities tend to be 20 or 30 stories and contain many more people, which means more energy-gobbling computers, lights and ventilation.
"With that many people on one piece of land, it's difficult, if not downright impossible, to generate all the energy you need on the site," said Mr. Pope.
Canada's climate also puts great demand on an office building. "If it's 40-below in Winnipeg, not only do you have to bring the fresh air in and heat it from minus-40 to plus-20, you also have to 'boil a kettle' to make some steam, to get some moisture in the air," said Mr. Pope.
An office building's positioning can also hamper the amount of solar energy that can be produced, particularly in big cities, says Chris Ouellette, senior manager of sustainable business at Royal Bank of Canada and a board member of the Canada Green Building Council's Toronto chapter. Buildings that fit into the city grid often can't be angled for optimum sun exposure, or may be shaded by the building next door.
Another important issue, says Mr. Ouellette, is the business community's architectural preferences, which have become entrenched. "We've been conditioned to like floor-to-ceiling glass," he said. "And glass is probably the worst thing you can use -- it's a building material that is almost incompatible with building net-zero energy buildings."
Mr. Ouellette applauds Del Ridge's efforts and says there's "no reason" why developers shouldn't be able to create office buildings that are 80 per cent more energy-efficient than the level required by building codes. But he admits that developers often see such efforts as risky.
"As an industry, they're used to doing things a certain way," he said. Designing a building that reduces energy consumption requires "a different type of thinking.
"A company needs deep pockets so if it goes over budget, it's not the end of the world. For some developers, it might be."
When asked whether he thinks the Del Ridge office building will attain net-positive status, Mr. Ouellette says, "Maybe not, but it's a moot point if it gets to 92 per cent more energy-efficient than the code."
Builders need more "carrots," or economic incentives, to be persuaded to build net-zero or net-positive structures, says Ian Theaker, a member of the Canada Green Building Council.
A typical office building can easily be made 30 per cent more energy efficiency than required by Leadership in Energy and Environmental Design standards, and it's "definitely doable" to get up to 50 or 60 per cent more energy efficiency.
"But to get to net-zero is another order of magnitude," he said. "We're talking 20 to 50 per cent more expensive than a regular building."
Mr. Pope says "handfuls" of developers have asked the government for money to build net-zero projects, but no specific federal programs encourage it.
Provincially, Ontario's Feed-in Tariff program provides incentives for developers to consider renewable energy such as solar or wind projects, but recent statements by the provincial Conservatives may put that program in jeopardy.
Del Ridge's Mr. De Sylva says he has encountered more hassle than support for energy-saving building plans at the municipal level.
"I was asked by a [city] councillor in January, 'How is it that you can do this and the other developers and builders say you can't?' I said, 'I get asked that a lot. Go ask them why they don't do it, because I know I can,'" he said.
"There's no [financial] incentives, none," Mr. De Sylva says. "I tell them they have a golden opportunity to treat this differently because when you treat it the same, you tell my competition 'Don't bother with green, don't waste your money or waste your time.'"
Another way for developers to designate their buildings "net-zero" energy users is to employ "scale jumping," says Mr. Theaker.
It works like this: When you can't produce enough energy onsite to bring a building to net-zero, developers can "allocate" the energy produced at another location to offset the shortage. "You can actually get to net-zero when you start expanding your boundaries and thinking about the process overall, to the district or the neighbourhood," he said.
The Centre for Green Cities at Toronto's Evergreen Brick Works is a good example, Mr. Theaker says. Because the office building's roof was not large enough for the 5,000-square-metre solar array that would be needed to achieve net-zero energy use, some of the required energy will come from the roof of a nearby industrial building.
Dave De Sylva of Del Ridge Homes has used this principle for a net-zero residential building under construction in Milton, Ont. The company is allocating the energy generated from a wind farm in Windsor to help the building hit its net-zero target.
In addition, because the company's GreenLife Business Centre in Milton is predicted to generate a surplus of 190,500 kwh of energy, Mr. De Sylva plans to allot that to residential projects that are having difficulty achieving the "net-zero" status on their sites.
But if its energy is being generated elsewhere, can a building really be called net-zero? Mr. Theaker says we must fundamentally change the way we develop our cities, and think about "district energy systems," instead of the energy consumption of just a single building. This concept is the norm in most of Europe, he says.