The Irwin House is set on a steep hill on a densely wooded site. The upper floor of the flat-roofed structure extends beyond the base of the building on two opposing sides; the side facing the driveway is cantilevered with a deck on the upper floor and the opposite side is supported on wooden piers set into concrete footers. The front and rear facades are almost identical; each facade has a set of wood stairs at the center of the wall leading to an entryway consisting of a narrow-stile door with a large fixed sidelight sheltered by a cantilevered canopy, while the remainder of the facade is blank. The side facades are heavily glazed with fixed and casement sash and narrow-stile doors. The base of the building is finished with stucco and the upper floor is clad in flush vertical cypress wood siding. At the driveway is a two-car garage with an upper-floor studio. A brick patio and flagstone pavers connect the house to the studio. The property also includes an in-ground swimming pool.
The Irwin House was designed by Victor Christ-Janer as a speculative house in partnership with builder Robert Roles. Christ-Janer and Roles purchased the property in 1953, which overlooked a neighboring bird sanctuary. The two worked together on several projects in New Canaan. The Irwin House was almost certainly one of the houses referred to in a January 1953 article in House & Home, in which Christ-Janer remarked that he had convinced Roles to construct two Modern speculative houses on Wahackme Road, and Roles responded, "I now think we can do a good modern speculative house in this area. I don?t care whether it has a flat roof or not; give me the plans of a house that makes sense and I'll build it" (House & Home, January 1953, 137).
The Irwin House was completed in 1953 and purchased by William A. Irwin, Jr., et. ux., in 1954. It was included in the 1955 Modern House Tour in New Canaan and described as one of the most "spacious" homes in the tour. A newspaper article on the tour remarked on the house's open planning: "Living areas are separated from sleeping rooms by the utility corridor and kitchen. The home can be modified to include three or six bedrooms, and the children's play area, with its own terrace and access from the lower level, can be completely isolated from the living area" (New Canaan Advertiser, 5 May 1955).
In 1961, Irwin sold the house to John H. and Jane Temple. In 1963, it was sold to Jarvis B. Cecil, a vice president at the Continental Oil Co. An additional bathroom was constructed in 1964. On January 3, 1972, a fire destroyed the main floor of the Irwin House. The basement level suffered water damage but was salvageable, and the separate two-car garage was untouched. By October 1972, the house had been largely rebuilt to the original plans with only minor changes.
In 1973, Howell D. and Linda K. Wood acquired the property. The Woods added a second-story studio over the garage in 1976, which the current owner believes was also designed by Victor Christ-Janer. In 1979, John H. Masters purchased the house, which was then acquired by Joseph W. Powell III and Cynthia M. Powell that same year. The Powells built a swimming pool and a one-story frame shed in 1984.
At an unknown date after the early 1980s, some alterations were made to the porches and balcony on the house. Historic photographs show that both the front and back porches used to have metal balustrades and offset narrow stairs that extended off the front of the porches, rather than the wide stairs of the current configuration. In addition, the second-floor balcony on the side facade facing the driveway used to have a metal balustrade and was supported on non-structural piers that extended up through the second floor. Currently, the porch cantilevers and there is no balustrade. It is unknown when these alterations took place. In 1999, Douglas H. Marshall purchased the property.