The cost of renovating City Hall has zoomed to an eye-popping $90 million — nearly 50 percent more than the original estimate, The Post has learned.
Matthew Monahan, a spokesman for the Department of Design and Construction, the city agency overseeing the project, confirmed last week that the latest price of upgrading outdated operating systems in the nearly 200-year-old structure is far more than anyone had anticipated.
Monahan said construction crews that began ripping open the historic building for emergency safety repairs earlier this year encountered more serious deterioration than expected when the $62 million budget was drawn up.
“This isn’t a cosmetic project,” he said. “This is a rehabilitation of the seat of government. The costs aren’t increasing as much as the scope of the work.”
There’s certainly plenty of evidence City Hall is the ultimate candidate for a “This Old House” makeover.
Construction workers found the roof was slowly rotting and were amazed at wide cracks in wooden attic beams not far from the second-floor “bullpen” that houses the mayor and his top aides.
In March, chunks of plaster fell from the ceiling of the ornate City Council chambers and an adjacent hearing room, requiring that both be shut for a couple of weeks for repairs.
The emergency repair that was supposed to cost $5.5 million has since grown to $8 million.
But the biggest budget buster is a new sub-basement for electrical and mechanical systems.
The price tag: a cool $18 million to $20 million.
“The building predates electricity,” explained Monahan.
He said that because it’s a landmark there was no way to build “up or out” to accommodate new equipment, leaving down as the only option.
In addition to new electrical, heating and cooling systems, City Hall is supposed to get a new elevator between the basement and second floors, a second elevator to connect the second floor with the third, a new fire alarm system and sprinklers.
Work is scheduled to be completed in 2012, in time to celebrate the building’s 200th anniversary.