But sustainability has created a new world. Advancing technology, whether software or hardware, increasingly is helping designers and construction professionals find the most cost-effective ways to determine and improve the sustainability of their projects.

"There are lots of tools to help people model buildings," says Alexis Karolides, a principal for the energy and resources team of The Rocky Mountain Institute, Snowmass, CO, and a member of the advisory board of the American Institute of Architects' committee on the environment (COTE).

Radiance Software, for example, allows architects to see where light will fall in a building. Other programs can profile the heating and cooling flow of a space, particularly important in odd-shaped spaces, or test for the presence of toxic materials.

The key is to use these programs as early as possible in the design process, notes Mark Dietrick, Director of Research and Development and a Senior Associate at the Pittsburgh office of architecture/engineering firm Burt Hill. The firm has used a beta version of the IES software.

"Certainly, energy consumption and environmentally sensitive design is increasingly important to us, and always has been," Dietrick says. "The only way to do performance-based design is with sophisticated tools, so that we get rapid feedback."

Technology doesn't just help during the design process--construction professionals also participate, and are not newcomers to using advanced software to test its equipment and installations. "Most companies that make air conditioning equipment have these programs too, and have for years," explains Richard Tilghman, a SVP of Chicago-based Pepper Construction Co., a Franklin Park, IL-based contracting mechanical engineering organization.

Where technology can prove useful in the future is eliminating the educated guesswork for the size of equipment needed, particularly critical with HVAC. Often, to avoid underperformance later on, engineers will install larger units than may actually be needed. Right-sizing based on scientific estimates could allow smaller units to be installed.

"Eventually, [technology] will tell us whether that's correct," said Bob Krier, president of Hill Mechanical Corp, a Franklin Park, Ill-based contracting mechanical engineering organization. But increasing dependence on technology can create an entirely new set of challenges--the old principle of 'garbage in, garbage out' can be compounded. "Things built virtually on the computer must be right, or we have a big problem," Krier says.

Another advantage of any of these programs is the knowledge of the cost and the rate of return of building green, and the costs and benefits of 'greening' specific design elements. "If you can quantify what you're doing, it takes away uncertainty," McLean says.

And the use of every possible tool will only become more popular as awareness increases and energy prices continue to remain high. Yet one thing, Karolides says, will never change. "There will never be a substitute for good design and a pencil."