"We wanted the building to be a good 21st century citizen," says Ripley Rasmus, senior vice president and design principal at HOK St. Louis, the lead architect of the Midfield project. "The terminal will have a minimum service life of 50 years so it must be a highly functional, effective tool that addresses the issues of the age. Sustainability is a natural function of that. We want the building to shape future ideas and attitudes."

Measures designed to lessen the new terminal's impact on the local environment include recycling 7,000 tons of old taxiway and roadway material as site fill, and the use of specific paints, concrete sealers, caulking, and carpets to lower emissions of volatile organic compounds. More than 90 percent of the materials were sourced from within a 500-kilometre radius of the site. IAA hopes that this "local is best" strategy lowered transportation costs, energy use, and pollution while boosting the local economy.

The terminal roof is constructed using a special membrane that is designed to shelter and shade the terminal's glass walls from the sun, but will still allow natural sunlight in through skylights. The roof surface also reflects energy, reduces heat gain, and channels rainwater for collection and use inside the terminal. The heating and cooling system is another notable sustainable design feature in the naturally lit Civic Plaza: a 43,000-square-foot circular central area containing shops, restaurants, security screening, check-in, and baggage claim. The heating and cooling system will only supply cool air to the 10-12 feet of space from Civic Plaza's floor upwards, while much hotter air gathers at the top of the building. The new system should save more than $12,000 a year.

"There will be a kind of natural convection," explains Rasmus. "It allows hot air to rise to the top and stratify. Meanwhile, the floor is cooled with water piped beneath, which keeps the temperature comfortable for people at floor level, although it will be around 95 degrees at the top of the roof. It is a very efficient strategy."

Source: "Designs Get the Green Light," Jane's Airport Review, September 2006.