WATERFORD — KBS Building Systems is reopening the local plant and putting 45 people back to work in mid-May.

The announcement came Thursday from Jerry McCormick, who heads the retail home center of the Paris-based business.

He said 45 people will be hired “to start off.” They will begin work May 16.

In December, KBS Building Systems shut down the Waterford plant and laid off 25 workers in a move that was called temporary. At that time, General Manager Ray Atkisson said he expected the plant to reopen April 1.

The company moved an additional 20 people from the Waterford plant to its Paris headquarters to work with its 155 employees on several major Massachusetts commercial housing ventures over the winter.

Atkisson said at the time that the lack of commercial building work in the state of Maine and overhead costs in the Waterford facility, including a propane heating system that costs $700 per day to operate, were major factors in the decision.

“It cost so much to heat that building,” McCormick of the plant where single-family modular homes such as Capes and Colonials and mufti-family units are built. The plant also had contracts with Massachusetts, including a 238 unit apartment complex in Lunenberg and 75 units in Hopkinton. “It’s just not cost effective.”

The main plant in Paris uses radiant heat from a boiler system, he said.

McCormick said Thursday that there are no firm plans to revise the heating system, and that any discussion would be dependent on how well business fares.

In late 2007, KBS Building Systems purchased the former Waterford Homes property in Waterford from a Massachusetts firm. Waterford Homes, a two-year-old high end manufacturing business, defaulted on mortgage and loan payments, and closed down in 2006.

The 17-acre property with a 30,000-square-foot manufacturing plant, located at 947 Waterford Road, was reopened for business early the next year with some 20 new hires and an increase of the KBS business by as much as a third of production.

But officials said the poor economy forced the plant to shut down about six to eight months later and to lay off its employees in that plant. It was reopened in 2008, but shut down temporarily when heavy snow caused the roof to collapse.

In 2010, more than 60 jobs were lost and the Waterford plant was shut down again when production lagged. But last spring, the plant was reopened and about 40 to 50 employees rehired when new commercial projects were landed and expected to bring the company through to 2011.

ldixon@sunjournal.com