Shorewood Heights, the 45-acre apartment community on the northeastern corner of Mercer Island, has been sold. Goodman Real Estate of Seattle and its investment partner, Pinnacle Investments, confirmed today that they have purchased the 645-unit complex for an undisclosed amount.

The Reporter first reported on the sale in late July.

Over the years, the apartment community has changed hands and expanded. The new owners plan to add more housing and amenities.

In 2002, 78 new homes were added. In 2007, the city approved a permit for the construction of 124 new apartments and town homes (to be converted into condos later). They were not built at the time and the permit remains open, city of Mercer Island officials said.

“Shorewood Heights is a landmark multifamily asset with the capacity for development of an additional 124 units,” a press release by the buyers said. The owners plan to complete additional improvements including a swimming pool, upgraded landscaping and an expansion of the existing fitness center.

The seller, Security Properties and Principal Global Financial, bought the property from HAL Real Estate for $141.3 million in December of 2005. The deal at the time was thought to be the region’s second-largest apartment transaction of the year behind Harbor Steps, a mixed-use, multi-story project in downtown Seattle. Seven years prior, the property had been purchased for $55 million. According to the King County Assessor’s Web site, the property is now valued for tax purposes at $100.1 million.

Pinnacle is a real estate investment, management and brokerage firm with offices and properties throughout the United States. The firm presently manages or owns more than 175,000 multi-family housing units (60,000 affordable housing units) in the United States and beyond.

Shorewood Heights was originally built in 1949 by Island resident Charles Clise.