A city commission must approve any changes to buildings in a downtown historic district in an effort to keep development standards consistent throughout the years, officials said.

The New Castle Historic Preservation Commission on Monday approved design guidelines for all new construction and remodeling in the district. Officials hope the guidelines will protect the city’s architecture and revitalize an area that has been struggling for years.

The initiative began last year after the commission was organized.

The guidelines include specifics on building materials for facades, window size and form, exterior colors, signs and landscaping. Metal siding, enclosed original windows and advertising billboards will prohibited for new projects.

But some developers say the new rules might cost them more money.

Jim Huddleston, who is restoring a building in the district, said making proper repairs to a building could become too costly.

“You can mandate anything you want, but nobody is going to invest millions of dollars into these buildings,” he said.

Commission member Richard McKnight said the new guidelines are needed, even though they may be a hardship on some developers.

“We have to do something,” he said. “We just can’t continue to watch buildings fall like dominoes on Broad Street.”

Some residents, including Noel Blevins, like the new initiative.

“If we could just get one success story – just one done – then maybe it would start the success,” he said. “It’s so important. It’s important we get some jobs, and it’s important you guys succeed.”