Buildings are the single largest contributor of greenhouse gases.

But with so much emphasis on the contribution of transportation emissions to global warming, this may come as a surprise to the average person.

"Forty-eight per cent of greenhouse gas emissions can be directly attributed to building, maintaining and operating buildings," says Rodney Wilts, founding director of Toronto-based Loop Initiatives Inc. Loop consults with developers across Canada, helping them implement environmentally sustainable practices.

Thankfully, he says there is a growing awareness of this huge contribution to climate change, and more and more developers are adopting environmentally sustainable building design and construction practices.

James Midwinter, executive vice-president of GWL Realty Advisors Inc., says about half of his commercial real estate development company's current building projects are incorporating significant 'green design' elements, with many seeking to meet Leadership in Energy and Environmental Design (LEED) standards.

"We think 'green design' is just going to become synonymous with 'good design' as we advance into a future of finite resources," says Mr. Midwinter.

Two such buildings GWL Realty Advisors is involved with are 18 York in Toronto and Bankers Court in Calgary, which are being designed for LEED Silver and LEED standard certification respectively.

Mr. Midwinter says most of the company's sustainability elements involve energy efficient design. "These include…better insulated building skins with triple-glazed windows, much more efficient and flexible mechanical systems, and lighting systems that dynamically reduce energy output based on the intensity of the daylight," he says. "We have also engaged in recycling of construction waste to significantly reduce the amount of waste going to landfill…and specified the use of low volatile organic compound (VOC) paints and carpets resulting in healthier, odour-free working environments."

GWL Realty Advisors is among many leaders who are designing or constructing green buildings in Canada.

According to Canada Green Building Council numbers, over 450 building projects are registered with the LEED program, with over 30 projects completed and certified in the last two and a half years.

Mr. Wilts says LEED is only the tip of the iceberg of what is happening globally in terms of green building trends. "People are also building green homes, more energy efficient buildings and aren't certifying," he says. "We're seeing more projects touting sustainability and more places mandating it."

Referring to organizations such as the Department of National Defence, the City of Toronto, Public Works Canada, and the Vancouver Organizing Committee for the 2010 Olympics - all of which are requiring their new buildings incorporate environmentally sustainable development practices - Mr. Wilts says green building is taking off across the nation.

And he says even more development would be green if people were aware that their businesses don't have to compromise profitability for sustainability.

According to Loop, there are three main advantages that corporations are now seeing they can gain through green building: they become known for meeting consumer demand for sustainable alternatives; they save money through the inherent economic efficiencies of green building practices; and they create environments that further employee attraction, retention and productivity.

"Knowledgeable building occupants - our customers - are increasingly becoming aware of these important building design attributes," Mr. Midwinter agrees. "Attributes that will affect their staff's level of comfort and the quality of the environments in which they operate. And, the fact is, while some green design elements may cost more, they frequently result in lower building operating costs…another benefit for owners and occupants.