There's a new plan for Plan B Burger Bar taking shape at the site of the former downtown Post Office.

Originally slated to open sometime last fall, Steve Grathwohl, an assets manager with Westport Property Management, the property owner, said it now looks as though the renovated building won't be ready for the popular restaurant chain to be open until spring.

Work on the site at 1262 Post Road came to halt for a period, he said, as the developers waited for a crusher to come on site to pulverize bricks from the demolished section of the former postal building.

All but the building's facade has been demolished. The facade, built in 1936, will be incorporated into the multi-tenant commercial structure. Plan B will be the anchor tenant.

"It's full steam ahead now," Grathwohl said. "You should see a lot of progress between now and the spring."

He said once the new section of the structure is completed, "the tenants have to get in and their own fit-out."

While the burger restaurant will take up 4,600 square feet of the building that fronts on the Post Road, the rear of the building will house four retail tenants.

"We are actively talking with four other groups," for the other space, Grathwohl said, although he declined to identify those groups.

The former Post Office was purchased by 1262 Post Road Holdings, LLC, an affiliate of Wilton-based real estate investment firm Westport Capital Partners, for $4.3 million in 2012.