Ropp and Castrodale paid $177,000 for the property in January 2007. The 1,800-square-foot home was built in 1923 in Lake Union.
Hammond is a research fisheries biologist at the National Oceanic and Atmospheric Administration.
He received an M.S. in fisheries from the University of Washington-Seattle.
Castrodale is a senior associate at Point B Inc., a management consulting firm.
He previously was vice president of professional services at RBE Inc. and as an engineering program manager at Boeing.
He received his B.A. and M.E. in aerospace engineering from Iowa State University.
According to BlockShopper.com, there have been 102 home sales in Wallingford during the past 12 months, with a median sales price of $512,500.
Address: 3435 Densmore Avenue N
Buyer(s): Carwyn F Hammond
Seller(s): Jonathan D Castrodale and Mary Katherine Ropp
Sale date: Nov. 2, 2010