“The last of the three houses in the Troutner Historical district, the Ada Poitevin house, was built in 1956 to provide living accommodations for Frances Migel’s mother. It is located on a 0.5 acre lot carved from the northeast corner of the Migel parcel next door. The house is a single story multi-sided building approximately 45 feet in diameter and about 1,400 square feet. An attached garage increases the floor space another 485 square feet. In plan, the house essentially has sixteen sides, although extensions for the living room and the carport modify this depiction somewhat as described below. The house supports a low, built-up gravel roof which slopes gently from the center outward to the building’s perimeter. The original roof configuration featured a skylight at the center, approximately 12′ in diameter, which covered the dominant feature of the interior – a circular “rose lanai” which serves as the focal point of the interior. It was quickly found that the skylight, although excellent for letting in natural light to the house, caused a significant “greenhouse” effect which proved unbearably warm during Idaho Falls’ hot summers. In about 1983, the owner reconfigured the skylight by covering it with a raised roof segment with windows around the side to keep some light infiltration. This modification successfully reduced the heating effects to a manageable level. Interestingly, Art Troutner visited the house after the roof alteration and is said to have remarked that “that is exactly what it needed.” This raised roof segment is the only major modification of the original building design, but it was done in a very compatible and appropriate manner.
For the most part, the exterior walls consist of numerous panels of between three and six horizontal courses of rabbited lap cedar siding beneath either large glass windows or panels of cemesto. Most of the side wall panels are 8′ wide, although three are 11′ wide for the living room. The windows were originally either single-pane plate glass or “thermopane,” but most of the single-pane units have now been replaced with doublepane windows. The appearance of the original design remains unaffected. One of the most intriguing and innovative aspects of this house is the roof structure. The roof depends on a large continuous steel ring, 1/4″ x 8″, at the center. This ring supports sixteen joists; most of the joists are 4″ x 10″, but 4″ x 14″ joists cover the living area and extended porch roof, and 4″ x 16″ joists extend outward for the carport roof. The ring is supported on the interior by 4″x 4″ timber posts and stone walls, arranged in arcs, to form the “rose lanai” described above. The lanai floor consists of quartzite flagstones which also extend outward toward the front entry and dining area.
In plan, this house can be described as a giant doughnut with the lanai at its center. As one faces inward at the front door, moving leftward around the house’s perimeter is the living room, master bedroom, bathroom, guest room, the access to the carport, a utility room, and the kitchen. Because of the basically circular configuration, each room is wedge-shaped.
Architecturally, the primary interest of the Poitevin house is the sixteen-sided plan with the central lanai underneath the original circular skylight above. The huge steel ring which supports the umbrella-like splay of roof beams is not only structurally interesting, but it is also major visual element of the interior. It is a tribute to the present owner that his design for covering the roof with a compatible modification retains the essential character of the original design (while solving the overheating problem of the summer sun). The fact that Troutner himself approved of the change many years later is a tribute to Mr. Benson’s innovation.
Source: National Register of Historic Places, Troutner District nomination form (https://history.idaho.gov/wp-content/uploads/2018/09/Art_Troutner_Houses_Historic_District_08000868.pdf)