In 1982, Seattle named itself the Emerald City in appreciation of our region's natural green environment. We've expanded a great deal since then, with a growing population, bustling neighborhoods and a vibrant downtown. Today, as new buildings rise up from South Lake Union to Rainier Valley and Northgate, we face a crucial moment in the shaping of our future. Let's visualize ways we can live up to that name we gave ourselves over 20 years ago.

To do that, we need to take a hard look at how the buildings we build interface with the natural environment we so cherish and want to protect. How well do they save energy — and energy costs? How well do they conserve our precious natural resources? How well do they really preserve our quality of life?

A new breed of architects has worked hard in recent years to answer these questions. They've created what they call "sustainable green building." Sustainable green building is not a radical or divisive idea. It's practiced here in Seattle and across the country. There are nearly 1,850 green building projects spanning all 50 states.

What does it mean to build green? In essence, green building means we minimize the impact of a building on the environment and create a more sustainable community in which to work and live. It also means we build to meet our current needs without compromising the ability of future generations to meet their needs. There are many ways to make a building green, from using recycled materials to illuminating rooms with natural daylight. These benefits mean we save money too — by reducing our energy costs.

Sustainability is not a new idea. The federal government has promoted it for decades. There have been nationally mandated energy codes since 1973, following that year's oil crisis. Energy codes are a basic part of municipal authority as well. In 2000, the city of Seattle began requiring all new or renovated city facilities over a certain size to be rated on the U.S. Green Building Council's national rating system, set by Leadership in Energy and Environmental Design (LEED). This action reflects the city's strong commitment to sustainable building and environmental stewardship.

Today, Seattle is a national leader in sustainable building, boasting 16 civic buildings that meet those standards — including our new downtown Central Library, Southwest Precinct Police Station and City Hall — with more on the way, including fire stations, branch libraries and community centers that will be high-performance, sustainable buildings.

The Seattle City Council is taking steps to make sustainable building standard practice. High on my list are "green roofs." A green roof is a thin layer of natural plants growing on a conventional roof. This provides insulation, lowering energy costs. The roof also collects large quantities of rainwater and uses it to flush the building's toilets and to irrigate the grounds. A green roof significantly decreases the need to filter storm water through costly treatment plants.

Green roofs are not only visually attractive; they reduce noise inside and carbon dioxide outside. They save energy because the building below them requires less cooling in the summer and less heating in winter. There are a growing number of green roofs being built in Seattle, thanks to many architects and builders in our area who recognize the importance of green building.

Our new Justice Center across from City Hall has a beautiful green roof and, as every day passes, its initial investment is paying off. A 2003 study, commissioned by Seattle's Office of Sustainability and the Environment, revealed the Justice Center is saving as much as $148,000 each year due to its green roof. Let's eliminate the obstacles that prevent green roofs from being built here so everyone can share in the savings!

In the coming months at Seattle City Council, I will be introducing legislation to incorporate a new green-roof incentive program into the city's land-use code. By providing a substantial benefit, we will make green roofs a viable option for all homeowners and developers in the city. Similar incentives already exist to encourage public plazas and affordable housing. There is no reason we can't do the same to encourage green roofs.

As the costs of construction and energy escalate, we don't have the luxury to waste our precious resources or our valuable time. Let's take this opportunity to grow in a way that sustains our region's celebrated environment and sets an example for the nation — and maybe even the world.

An effective green-roof incentive in our building code will demonstrate our civic commitment to a healthier, more livable city. It's no longer enough for us to simply hope for green in Seattle. Together, with a strong and enduring commitment, we can truly make Seattle a shimmering Emerald City.

Seattle City Councilman Peter Steinbrueck, an architect and member of the American Institute of Architects, chairs the council's Urban Development and Planning Committee. He can be reached by e-mail at peter.steinbrueck@seattle.gov, or at (206) 684-8804.