Housing on Grassy Key is seeing big changes.

The grand opening of the U.S. Coast Guard's Green Building home project on Gibson Street is rapidly approaching. The first of three three-bedroom homes, three duplexes and a maintenance building will be open to the public on March 24 from 1 to 5:30 p.m.

The homes are certified by LEED, Leadership in Energy and Environmental Design, for meeting rigorous technical requirements for energy and water efficiency, indoor air quality, non-toxic materials and environmental performance. LEED Commissioning Services were performed by SEQUIL Systems Inc. of Delray Beach.

"These homes are healthier, more comfortable, more energy efficient, more durable, and have a much smaller footprint than many conventional homes," said Susan Grant, project manager for Viteri Construction Management Inc., which is under the U.S. Green Building Council umbrella.

The U.S.G.B.C. is a nonprofit membership organization whose vision is a sustainable built environment within a generation. Its membership includes corporations, builders, universities, government agencies, and other nonprofit organizations.

Since UGSBC's founding in 1993, the Council has grown to more than 14,500 member companies and organizations, a comprehensive family of LEED green building rating systems, an expansive educational offering, the industry's popular Greenbuild International Conference and Expo (www.greenbuildexpo.org), and a network of 77 local chapters, affiliates, and organizing groups.

Thinking ecologically is nothing new to the Florida Keys. It was not long ago island homes used cisterns and septic tanks. Modern Green technology has the same concept, but focuses on conservation of scarce resources rather than the holding tanks of old.

Green buildings -- structures created using processes that are environmentally responsible and resource-efficient throughout a building's life-cycle -- focus on decreasing the carbon footprint of a home through various reusable and energy efficient materials. Reducing the amount of carbon dioxide, believed to be a primary cause of ozone depletion, generated in both the long and short-term is the goal of sustainable building projects.

Builders and designers, in this case Viteri and architectural and engineering Firm Wolfberg Alavarez Partners of Coral Gables, go out of the way to incorporate erosion controls during construction, recycled metal studs and tresses, special paints and adhesives, landscaping with no invasive plants or need for irrigation, high-efficiency electrical and plumbing fixtures, energy efficient appliances and specially insulated wall panels.

"These houses have been designed and constructed as exceptional housing," said Construction Branch Chief Robert Hueller, U.S.C.G. Facilities Design and Construction Center. "It is one of the first Coast Guard homes to be built as a LEED home.

"The Coast Guard is excited about this project. The new home owners are excited about these homes. ... A lot of consideration has gone into these homes so that it will all fit into the design of the neighborhood. The construction is way above normal standards."

Hueller added that the project was important for the Coast Guard because it's hard to find good rentals for military personnel who are here for short periods of time. As the Coast Guard looks for ways to meet its needs, it will continue to measure up to these silver level LEED homes, he said.

The Coast Guard and its personnel aren't the only ones to benefit, according to local officials.

Marathon City Manager Roger Hernstadt said The City of Marathon is extremely proud that the U.S. Coast Guard has successfully completed the construction on Grassy Key.

"We congratulate Lt. Commander Robert Hueller, Project Manager Carlos Viteri and Contractor Paul Peterson for their efforts, and thank their team for the close collaboration with the City of Marathon staff," Hernstadt said. "We believe this project is a model that can be adapted and replicated to provide affordable housing to meet the needs of working families in our community."

Peterson said he is very pleased the Coast Guard brought this project to Marathon.

"We're glad they did it here, and glad they went through the extra cost to keep the carbon footprint as small as possible. This is a hometown project with 95 percent of the workers on the project from the Keys and Homestead."

After the public open house on March 24 from 1 to 5:30 p.m., there will also be a ribbon cutting ceremony on Wednesday, April 9, at 9:30 a.m.