UPDATED, Friday at 12:45 p.m.: The state Treasury Department announced that Governor's Office personnel will relocate during the renovation to state-owned 225 West State Street, which is near the State Museum. Department of State personnel currently working from that location will relocate to state-leased 33 West State Street. The Treasury says preparations will begin immediately so personnel can move "as soon as practicable."

TRENTON — More than 15 large windows in the executive wing of the Statehouse have been boarded up with plywood in recent days, the latest sign that officials are serious about a planned renovation project that could cost $300 million.

Deterioration of cornices, chimneys and woodwork at the Statehouse might not be easily detected by passers-by – but there’s no missing the wood-covered windows on both the front and sides of the nation’s second-oldest capitol building in continuous operation, dating to 1792.

“The fact is that this is an unsafe building for all of us to be operating in every day,” Christie said.

“Those windows are boarded up now because those windows were judged when they were inspected to be ready to fall out of the building,” said Christie, who said the state Department of Community Affairs is doing the inspections.

The Christie administration plans to spend around $300 million to renovate the statehouse, including $20 million to upgrade its legislative wing, $20 million to fix an office building across the street and $55 million set aside for contingencies.

Christie announced the plan at the end of November, but since then little additional information has been revealed. The Economic Development Authority still hasn’t approved borrowing the funds. But asked about it this week, Christie said it’s full-steam ahead.

“This is going forward. I told you – it’s done, it’s over, it’s moving forward,” Christie said.

“We’re not going to allow people to operate in unsafe space. I will be the last governor who will operate in a firetrap, and that’s what I’ve been doing for the last seven years,” Christie said. “Fortunately for me, maybe unfortunately for some of my adversaries, there was never a fire. But we need to get out of here before there is, before there’s any loss of life.”

There’s been some grumbling about the costs, from gubernatorial candidates such as Lt. Gov. Kim Guadagno, who likened the plans to the Palace of Versailles, and Sen. Raymond Lesniak, who said he’d go to court if the plan proceeds without a vote of the Legislature.

The State Capitol Joint Management Commission, a panel equally divided between executive and legislative branch appointees that oversees the Statehouse complex, passed a resolution endorsing the full renovation at a Jan. 31 meeting.

Christie says the four-year project is expected to start by June.

“If not earlier, if not earlier,” Christie told reporters, whose press-row offices are among those that would be vacated. “Get ready to be mobile.”

The Statehouse was built in 1792 and has been renovated or extensively repaired five times since, though not since the 1950s.

New Jersey: Decoded cuts through the cruft and gets to what matters in New Jersey news and politics. Follow on Facebook and Twitter.

Michael Symons is State House bureau chief for New Jersey 101.5 and the editor of New Jersey: Decoded. Follow @NJDecoded on Twitter and Facebook. Contact him at michael.symons@townsquaremedia.com.