Architecture need not always be serious. And nowhere is lightheartedness more fitting than in a vacation house. One such playful example is the Tower House'a 2,500-square-foot structure on a sloping, wooded site in Ulster County, New York, about 100 miles north of Manhattan. Designed by New York City'based Gluck+ as the mountain retreat for one of the firm's principals, Thomas Gluck; his wife, Anne Langston; and their two children, the house resembles a cross between a Modernist skyscraper and a tree house. It is completely glass-clad and has three bedrooms and adjoining baths stacked one on top of the other to support a living and dining room cantilevered 30 feet from the ground. A switchback stair, with bright-yellow treads and risers, connects all four levels and leads to a rooftop deck. The goal, says Gluck, was to create an aerie within the trees and take advantage of views of nearby Catskill Park, a vast state forest preserve.

Completed last summer, the house is the most recent structure built on the 19-acre parcel purchased more than 40 years ago by Peter Gluck, Thomas's father and firm founder and principal (the practice was known until recently as Peter Gluck and Partners). The site contains an almost 200-year-old farmhouse and two other buildings the office designed'a guesthouse completed in 1995 (RECORD, April 1996) and a study space built in 2003 for the senior Gluck's wife, Carol, a Japan scholar.