Yale prof designed house for his sister and brother-in-law Edward McCormick Blair Jr. and his wife, Frances, have sold their Lincoln Park house—an orange brick building whose façade masks a light-filled, 1,369-square-foot courtyard.

The house had its origins in 1993, when the Blairs paid $840,000 for a quarter-acre lot and commissioned Frances’s brother, the Yale architecture professor Peter de Bretteville, to design a ten-room house on the site. Completed in 1995 and spanning four city lots, the house has three bedrooms, a metal roof, and a 71-foot-long gallery illuminated by high, south-facing black-framed windows.

Edward Blair is a principal at the wealth-management firm William Blair, which was cofounded by and named for his grandfather. He is also a descendant of Robert McCormick, who helped his brother Cyrus develop and manufacture the revolutionary mechanical reaper. Frances is a descendant of the San Francisco-based Spreckels family, whose fortune came from California beet sugar.

The couple listed the house for sale in May 2006 with a $5.2-million price tag (which later dropped to $4.9 million). In October 2007 they closed a deal to sell the house and a small adjacent lot for $5.075 million. Neither the Blairs nor their agents, Heather Bilandic and Ellen Benninghoven of Koenig &Strey GMAC, would comment on the sale.

Photograph: Chris Guillen