Vancouver is known in many circles as the city of glass, a nod to the glass condominiums that dominate its skyline.

But a University of British Columbia urban design expert says the city's reliance on glass towers is contributing to climate change and undercutting the city's goal of being the greenest city in the world by 2020.

Patrick Condon, a UBC chair in landscapes and livable environments, says glass is a terrible insulator that forces condo dwellers to crank up their heat in the winter and blast air-conditioning in the summer.

"It's wonderful to see beautiful sunsets across the water," Condon told CBC's On The Coast. "But it's five hours of blazing sun coming into your living room. That's not so great."

Condon's remarks come after recent reports that global architects and engineers are calling for a ban on glass buildings as scientists warn of a climate crisis.

New York City Mayor Bill de Blasio announced in April a ban on all-glass buildings, but later backtracked to a revised plan that called for more energy-efficient materials. The city is aiming to become carbon neutral by 2050.

'It's so hot in here'

About 40 per cent of global carbon emissions come from building, heating, cooling and demolishing buildings, according to the International Energy Agency, an inter-governmental organization.

Architects say glass buildings aggravate the problem because they allow heat to easily pass in and out, making it difficult to keep temperatures stable inside.

A BC Hydro report this year found that newer highrise buildings use twice as much electricity as highrises built in the 1980s. (Christer Waara/CBC)

Developers have refuted those claims, pointing to more energy-efficient alternatives such as double-pane glass. The floor-to-ceiling windows also lure in buyers seeking Vancouver's ocean and mountain views.

"My own experience is the view, after a while, is not as fantastic as it was the first couple of months," Condon said.

"You become more aware that, 'Oh my God, all my pictures are turning blue, my carpets are sun-scorched and it's so hot in here.'"

A BC Hydro report earlier this year found that newer highrise buildings use twice as much electricity as highrises built in the 1980s, even though the newer buildings are marketed as energy efficient.

Condon said the inefficiency of glass is at odds with Vancouver's greenest city action plan, which fails to address the use of glass in new developments.

For the city to meet its 2020 emissions targets, "you'd have to rip the glass skins off of every building," he said.

The glass on buildings must also be replaced every 30 to 40 years due to wear and tear, Condon said. When that time comes, he said, developers could incorporate better insulating materials.

Listen to the full interview with Patrick Condon: