Although their primary residence is an Art Deco apartment in Philadelphia, for 20 winters Ed and Betsy Cohen have retreated to a Casey Key home that famed Sarasota School of Architecture architect Paul Rudolph built in 1957. The horizontal, 4,500-square-foot beach house, built of Ocala sand, concrete and glass, hugs the ground between the Gulf of Mexico and the bay and offers spectacular views of both. When the Cohens purchased the property, their first round of work "took the form of redemption," says Betsy.

"There was shag carpeting over the terrazzo floors and previous owners had closed in the skylight," she explains. "Then in 1993, Ed and I began to renovate with current technology and with products that we think Paul Rudolph might have used had they been available."

The couple redid the electrical system, added a fireplace and moved a staircase to give themselves better views of the water. They remained sensitive to the house's original lines and its flow, says Betsy. "With everything we did, we strove to see the house through Rudolph's eyes," she emphasizes.

They replaced the thin veneer birch of the kitchen cabinets with birch wood and traded out the mica countertops (which had not worn well) with Corian. The Cohens furnished the home slowly, using modern furniture dating from the Bauhaus movement forward and maintaining the neutral colors that Rudolph chose. On the west-facing walls of glass they added disappearing blinds to manage the heat.

"We left the walls unfinished Ocala block, and we've used very little furniture," says Betsy. "The house is a marriage of living space and nature. The sand, the live oaks, water and sky are the principal decorations."

In 1995, the Cohens responded to their growing family's desire to vacation together-three generations use the property, the youngest member being only two years old. They purchased property next to their home and selected New York architect Toshiko Mori to design a guest house. The intention was to give everyone both privacy and communal space in a flexible floorplan. Governmental regulations that didn't exist during Rudolph's time meant that the new structure would have to be on stilts, 12 feet above ground. Mori's challenge was to design a new house that harmonized with the existing one and folded into the beachscape despite its height.

The Cohens and Mori met in Maine, where the Cohens have a home. They were on the board of trustees of the Farnsworth Museum in Rockland, and Mori was the museum's architect. They discovered they shared an admiration for the Sarasota School of Architecture and an interest in preserving its legacy. Subsequently, the Cohens invited the New York architect to Sarasota to see their Paul Rudolph home and the site for the guest house. Mori also spent time at Marie Selby Botanical Gardens, researching indigenous plants and studying landscape and weather patterns of this coastal community and of the barrier islands.

"I designed the guest house in my mind's eye while I was staying there in 1996," reveals the 40-something architect. "It is a splendid piece of beach property; and I knew I could not impose East Coast ideas on such a delicate site. It would have to be a thoughtful house, appropriate to the beach and to the climate and most of all to the Rudolph house already there. My design would have to respond to the Rudolph masterpiece without imitating it. But I definitely wanted to push forward the legacy of the Sarasota School. And, additionally, I needed to incorporate the Cohens' wishes for a house that addressed privacy issues for the people who would be using it. The project called for reacting, responding and creating."

The T-shaped, two-story house is 2,800 square feet (1,900 under roof) and constructed of concrete block, glass and galvanized steel. An exterior staircase leads guests to private suites as well as to the communal swimming pool area. The floors are terrazzo in the public rooms and bamboo in the three bedrooms. Stainless steel was the choice for the kitchen. The furnishings are neutral and spare, with Japanese baskets and photography providing the art. Nearly all the furniture and storage areas are built-in and are intended to be part of the architecture of the home.

Sarasota's Wilson Stiles, an interior designer and historic preservationist who is one of the participants in the upcoming Sarasota School of Architecture symposium and tour (Nov. 1-5), calls the guest house "a little jewel." Stiles says that the house, which is nestled in a hardwood hammock, is "really a delicate tree house that seems to float among the oaks in contrast to the way that the Rudolph house is very much a house of the earth. The elevation of the guest house is a response to building codes; but it offered the architect a nice challenge, and she made the most of it." Mori managed to blend the structure into its site and make it harmonize with the Rudolph house, he adds. "Yet Toshiko Mori's design is not a Rudolph reflection. Both in scale-for it's quite small-and in feeling, it seems to me Japanese and serenely Zen-like. The architecture is respectful of the existing house but it definitely stands on its own."

In 2000, Mori won the New York City/American Institute of Architects award for the Cohen guest house. The dwelling has subsequently been featured in Architecture magazine, Details and this past summer it was the cover story for an international architecture magazine published in Milan.

Betsy Cohen says that everyone in the family appreciates every moment in their winter retreat. "Wherever we are, either in the main house or the new guest house, it's like sitting in an art box between the bay and the Gulf with unimpeded views," she explains. "The property is extraordinary, the architecture is extraordinary, and we are extraordinarily lucky to have it."

The Cohen main house (officially called the Burkhardt House) and guest house will be venues for the "Dinner with an Architect" series during "An American Legacy: The Sarasota School of Architecture" tour and symposium. Each dinner will take place on Friday, Nov. 2, and tickets are $75 each. For more information call 388-1530 or purchase tickets on the Web at wwwSarasota-Architecture.org.