They don't build office towers like they used to--and that's a good thing. Nowadays, they're built with sustainability in mind, and here in Toronto, there are hundreds of projects with LEED certification--which stands for Leadership in Energy and Environmental Design.

Although the program isn't perfect, it's a step in the right direction, and while the lower levels of certification may not be exceedingly difficult to attain, Platinum certification, the pinnacle of green construction seals of approval, only goes to projects that score above 80 on the LEED scorecard. There are five categories on the scorecard, so there are many ways to go about achieving the approval.

Here's how some of our local environmental champions have done it.

TD Centre Tower
TD is the green bank, after all, so why not have a green public image? The TD Centre Tower at 100 Wellington is the first office complex in Toronto to achieve platinum level certification under the Existing Buildings: Operations and Maintenance Program. They set up a Green Portal which displays the real time energy usage stats of all six TD Centre towers; the Wellington tower currently has the lowest energy usage of the bunch, with 739,362 kwh used between August 19 and November 19.

RBC WaterPark
Construction of the 900,000 square foot RBC WaterPark tower won't be complete until 2014, but it too will boast a bevy of environmental features elevating it to platinum level. It utilizes a deep lake water cooling system which sucks in chilly lake water to cool the air, and most of the windows have glazing which provides better insulation and brighter natural light. An outdoor air system will keep warm and cool air separated, generating a cleaner indoor atmosphere.

Chapelview Apartments
This Brampton apartment building is the first affordable housing unit in Canada to reach platinum status. The 200-unit building uses 50 per cent less power and 46 per cent less water than a regular apartment of similar size. It has a trash sorting system with separate chutes for different types of waste. Double glazed, argon-filled windows minimize heat loss, and individual ventilation ducts in each unit stop odours from drifting over from other units. New tenants even receive a care package upon moving in which contains low VOC cleaning products.

Archetype Sustainable House
This model house uses enough sustainable building practises to rack up a solid 92 out of 100 on the LEED checklist. The Archetype model home is on display at the Living City Campus at Kortright in Vaughan if you care to take a peek at it. It contains so many environmentally friendly features that listing them all would make this article a mile long. To name a few: a micro-cogenerating station produces heat, A/C, electricity, and hot water, cisterns capture and store rain water, and low flow plumbing reduces water usage.

Knoll Toronto Showroom
Since 1938, Knoll has crafted intelligent office furnishings and has been regarded internationally as a leader in design. They consider themselves pioneers in clean technology and all Knoll architecture is required to be LEED certified. So, in 2009, Knoll upgraded their Toronto showroom to platinum specs. They built their showroom with low-VOC paints, carpeting made from post-consumer materials, big windows for loads of natural light, Energy Star-rated appliances, and locally-sourced wood. Oh yeah, and all their products are made out of sustainably sourced materials.

Enermodal Toronto Office
Enermodal Engineering is a design firm focused on developing sustainable buildings. They have overseen 250 LEED projects in North America, with a third of those being in Canada. Naturally, they build their own offices with environmental standards in mind. The Toronto office saw significant reduction in water usage, construction waste, and VOC emitting paints to gain its platinum seal. With a specialty in environmental design, it's only fitting to lead by example.

Writing by Chris Riddell. Photo of RBC WaterPark.