SOMBA K'E/YELLOWKNIFE - Yellowknife has been named the most sustainable small city in Canada for the third year in a row.

The honour comes from Corporate Knights magazine, a quarterly publication which describes itself as "the magazine for clean capitalism" on its website.

Mayor Gord Van Tighem said there are many factors that puts Yellowknife ahead of other small cities, including neighbouring capital Whitehorse -some the city actively capitalizes upon while others come with the territory.

"A lot of it relates to work we've been doing on community energy planning work we've been doing on reducing our environmental footprint, greenhouse gas reduction," said Van Tighem.

The mayor pointed to the city's stringent energy-efficiency standards for homes and businesses, and the switch made to wood pellet boilers in its facilities as reasons why the city scores so well.

"We have the most commercial wood pellet boilers in any community in North America right now," said Van Tighem.

"Then there's the amount of people who walk, bike, or cross-country ski to work.

"It's a very compact city, so it is easy to get around on a bicycle, walking, skiing. You're never more than 20 minutes from anywhere, really. That's partly planning, partly an accident."

City councillor Bob Brooks described Yellowknife as a "mini metropolis in the middle of the wilderness."

Van Tighem said the city's high energy-efficiency standards are now being adopted by the territorial government. City council passed a bylaw in January, 2008 requiring new homes to meet a national EnerGuide rating of 80, which is relating to how well the home retains heat. Energy standards elsewhere typically fall at an EnerGuide rating between 65 and 72.

Brooks said the city has already met its target of 20 per cent reductions in greenhouse gases below 1990 levels, which was set out in 2002 with a deadline of 2013.

"We're trying to set new targets so we can be even more of an example of what could be done," said Brooks.

Tighem did acknowledge a few challenges the city faces. One of which is affordable housing, a point the mayor reiterated in his annual state of the city address to the Yellowknife Chamber of Commerce on Wednesday.

"It's all well and good to come up with policies and strategies, but are they affordable to the end-use?" asked Van Tighem.

The mayor said the cost of transporting materials up to Yellowknife, and the housing market itself, have driven costs up sustainability.

Also, the price of power is much higher than he would like it to be.

"There's almost a fixed cost of producing electricity and there's not enough of us to drive it down," said Van Tighem. He added that the NWT Power Corporation should try to be more innovative in its ways of reducing costs.

"Other than housing and utilities, we're pretty well-off," said Van Tighem. He said the city will continue trying to reach new sustainability goals like tapping the potential of geothermal heat from Con Mine.

"All the new construction planned right now has been in here to see that, if the geothermal gets up, if they can get hooked up to it," said Van Tighem.

"Some of the existing buildings have come in and inquired about it. There's great interest in that."