Issaquah, Washington-based Costco Wholesale Corp. has purchased the 20.5-acre site in Franklin where it plans to build a new store for $4.6 million, according to state records.

Construction of the store is expected to begin this week and be complete in November, according to a news release from the city of Franklin.

The store site is located northwest of South 27^th Street and Drexel Avenue and it was sold to Costco by Milwaukee-based financial services company Northwestern Mutual. The site is adjacent to Northwestern Mutual’s Franklin campus, which the company plans to vacate next year when it moves about 2,000 employees to its downtown Milwaukee headquarters campus upon completion of its $500 million project to rebuild its North Office Building.

Northwestern Mutual also recently sold 119 acres across South 27^th Street, in Oak Creek, to an affiliate of Wauwatosa-based real estate development firm Wangard Partners and Pewaukee-based real estate development firm Siepmann Realty Corp., which plan to develop hundreds of residential units and some commercial space there.

Costco plans to build a 162,000-square-foot store at the 27^th and Drexel site in Franklin.

The company is also building at store in the Pabst Farms area in Oconomowoc.

Google Street View images of the Franklin Costco store site: