Equity Residential, the country's largest apartment owner, paid $12.15 million this week for a half-block site in South Lake Union where it already has proposed a 275-unit complex.

The bulk of the site, mostly parking lots on Minor Avenue North between John and Thomas streets, was owned by Seattle developer Touchstone, which acquired it in 2010 from Cascade Natural Gas.

Touchstone still owns the building on other half of the block, facing Fairview Avenue North, that had been Cascade's headquarters.