Tangelia Sands watched Ario Lundy build affordable houses in her Liberty City neighborhood for several years, admiring them from afar. Next month, she and her four children finally will move into one of those homes.

Not only will it be affordable, it will be the first affordable ''green'' house in Miami-Dade County.

Sands, who arises every morning at 3:15 to begin driving her Metrobus at 4, recently visited her under-construction home with two of her children to see exactly what they will be getting -- completely by chance, as Sands chose the site and not the house. They met with the architect, the builder, Opal Jones of the Miami-Dade Housing Foundation and Patricia Braynon of the Housing Finance Authority.

''I put out the challenge to build green affordable housing, and one architect and one builder responded,'' Braynon said. ``Here they are.''

Lundy's Palmetto Homes of Miami is the builder; Steven Ross Luria of Miami is the architect who converted the original house plan done by Arcon Engineering of Hialeah into a green prototype.

The construction cost of the home will be between $165,000 and $180,000, estimates Lundy. (Sands is paying $225,000, a standard price for an affordable home, according to Braynon).

The additional green components add $12,850 to the cost of the house. But, says Luria, these upfront costs mean Sands will save $2,000 a year in energy bills, which delights her as much as having impact-resistant windows. The green materials will pay for themselves in only six years.

GREEN ELEMENTS

Among the green elements are insulated, solid concrete walls; insulated air conditioning ducts; recycled oak flooring; energy-efficient appliances; compact fluorescent lights; low VOC paints and drought-resistant landscaping. The house will be quiet as well from all the insulation.

There are about 150 people in the process of applying for affordable housing through the Miami-Dade Affordable Housing Foundation at any one time. They take financial classes, set up a saving account and join the waiting list. The process can take a month or years. For Sands, it took about a year. She looks forward to the day ''when I come home from work, I can shower and lie down in quiet,'' she said.

To assemble the green components, Luria studied the standards of the U.S. Green Building Council, the Florida Green Building Coalition and the federal Energy Star program and selected those he felt would qualify the house for a green LEED residential certification.

LEED, awarded by the Green Building Council, means Leadership in Energy and Environmental Designs, and it signifies that the building performs exceptionally well in five arenas: sustainable site development, water savings, energy efficiency, materials selection and indoor environmental quality.

Additional standards set by the Florida Green Building Coalition include hurricane protection, such as impact-resistant windows and reinforced garage doors.

Here are some of the elements Luria and Lundy have used to build a green home:

• Solid concrete walls were poured using a insulated concrete forms that result in walls 5 ½ inches thick. Styrofoam on the interior and exterior of the concrete remains in place, giving the walls an R value of 25 to 30. The R value measures the resistance to heat transference. (The South Florida building code requires R5 for masonry walls.) The walls will prevent so much heat build-up that the air conditioning unit for the home can be 2.5 tons compared with a 3-ton unit required for the identical nongreen house next door.