MECHANICVILLE — A Porter Corners contractor hopes to be renting out offices in a former Catholic school in Mechanicville by next summer.

Keith Harris has purchased the old St. Paul’s Catholic School on William Street from the Albany Diocese and is working with city officials on the plans for renovation.

On Monday afternoon he toured the three-story brick building and said specifics for its transformation into rental space will be determined by future tenants.

“I hope to find the first tenant that will be interested in the majority of the building and we’ll build to suit their needs,” he said. “I’m thinking there will be offices on the first floor and maybe apartments or condominiums on the upper floors.”

Harris, 43, said he grew up in Ballston Spa and runs his small construction business from offices in Porter Corners.

“I’ve built quite a few homes, but this is my first time doing a project like this,” he said. “The overall condition of the school is very good and the city’s willingness to work with me encouraged me to go forward with the plan to buy the school.

Harris negotiated to buy the school for about a year and the diocese agreed to accept $50,000.

He said it will take a great deal more money to replace the heating system and renovate the interior of the building.

“Kids have vandalized the school over the last couple of years and the roof has leaked around the downspouts, but overall the building is in good shape,” he said.

A large room that served as the school’s auditorium and gymnasium has the remnants of burned materials in the middle of the floor where a fire had been started. On the upper floors, stored papers and books in classrooms have been strewn about and fire extinguishers have been emptied in a hallway.

An open vent on the roof allowed birds to enter the school and feathers and droppings can be seen throughout the building.

Harris said he has a copy of the original blueprints for the building that are stamped 1924 and were drawn by a Troy architectural firm.

St. Paul the Apostle Church on North Main Street in Mechanicville was built in 1912, and the congregation was merged in 1977 with Church of the Assumption in the city.

The church is at the corner of North Main and William streets and the school is behind it.

Mechanicville Mayor Anthony Sylvester said he is excited to have development in a building that has sat idle for years.

“I took a tour of the building and it’s really a gem in the rough,” Sylvester said Monday. “We’re 100 percent behind [Harris]. This looks good for Mechanicville.”

As property owned by the church, it has been exempt from property taxes.

Harris said he isn’t looking for a tax break on the property.

“I’m going to be doing this on my own. I talked with [Saratoga Economic Development Corporation] and the [Industrial Development Agency], but I’m not going to go through those programs,” he said.

Harris said he felt this is a good time to invest in real estate in Mechanicville.

A $40 million rail yard redevelopment project, the construction of a new Northway exit west of the city and the anticipated construction of a high tech industrial park in Malta and Stillwater are examples of a bright future, he said.

“I’m confident there are good things coming for this little city,” he said.