If you were clever enough to snap up a house by Louis Kahn, one of the most revered architects of the 20th century, in the Chestnut Hill section of Philadelphia in 1981, as Robert Gallagher, a dentist, and his wife, Lynn, did, it was $152,500. It had just one bedroom, but its lineage was awfully smart: it had been built between 1959 and 1961 for Margaret Esherick, a relative of the sculptor Wharton Esherick, who gave the home its name, Esherick House. By 2004 the assessed value of the home, according to 2006 county tax rolls, was $303,000. But what do bureaucrats know of beauty? On May 18, the Wright auction house in Chicago, which specializes in 20th-century art and design, will be offering Esherick House in its Important Design sale. Richard Wright, the firm’s president, estimates that it will bring $2 million to $3 million. “Louis Kahn only did three major architectural homes in his career,” Mr. Wright said. “Joe Rosa, the curator of the architectural department at the Art Institute of Chicago, who wrote a book on Louis Kahn, feels that it is his best residential structure. He articulates his mature style in the monumentality of the facade, in the treatment of the windows, and then the warm and human quality in the interior.”