Auer's Boat House

The Herbert and Katherine Jacobs First House, commonly referred to as Jacobs I, is a single-family home at 441 Toepfer Avenue in Madison, Wisconsin, United States. Designed by the architect Frank Lloyd Wright for the family of the journalist Herbert Jacobs, it was completed in 1937 and is cited as Wright's first Usonian home. The house is a single-story, L-shaped structure covering 1,550 square feet (144 m2). It sits on a slope that descends toward Lake Wingra to the southeast.

The Jacobs First House was one of three major buildings that Wright designed in the 1930s, along with the Johnson Wax Building and Fallingwater. Prior to the Jacobs House's construction, most of Wright's clients had been wealthy; in contrast, Jacobs was a young newspaperman who worked for the Capital Times and earned no more than $35 a week. In August 1936, Jacobs asked Wright to design a house costing no more than $5,000; the architect devised the initial plans within two months. The structure ultimately cost $5,500 including land, and it became so popular that the Jacobses charged visitors admission. The Jacobses lived in the house only until 1942, when they moved to a farm in Madison, where they built their second house. The original house was then resold several times. The art historian James Dennis renovated the building after acquiring it in 1982; he continues to own the house as of 2025.

The Jacobs House is divided into two wings, which run near the western and northern boundaries of the site. It has a brick and board-and-batten facade facing west toward the street, as well as large windows and glass doors facing a garden to the southeast. The house rests on a concrete pad foundation, with a radiant heating system embedded into the floor, and it is covered by three levels of flat roofs with protruding eaves. There is a brick chimney mass at the corner of the L, as well as a carport to the north, which contains the house's main entrance. The house's western wing includes the living room and a dining niche, with a bathroom and combined workspace–kitchen inside the chimney core. In the northern wing are three bedrooms (one of which is labeled as a study), in addition to a room known as a "shop".

When the house was finished, observers commented on its materials, proportions, and relationship to the surrounding landscape. The popularity of the Jacobs House prompted people from across the U.S. to ask Wright to design their houses, and Wright devoted his later career to Usonian designs. Several of its architectural features were later widely used, including its board-and-batten walls, radiant heating system, and modular floor grid. Over the years, the house has been detailed in several books and depicted in numerous photography exhibits. The Jacobs First House was listed on the National Register of Historic Places in 1974 and designated as a National Historic Landmark in 2003. It was designated as part of The 20th-Century Architecture of Frank Lloyd Wright, a World Heritage Site, in 2019.