The iconic multi-faith Cadet Chapel was designed by Walter Netsch and completed in 1962.

Courtesy Of The U.S. Air Force Academy

The landmark Cadet Chapel at the Air Force Academy will close Jan. 1 for a major restoration project that could take up to four years.

The project was originally expected to start last summer, but the academy said Monday it was pushed back while the school found a contractor with experience in renovating historic buildings.

The restoration includes replacing the chapel’s aluminum skin, removing and cleaning 24,000 stained-glass tiles, stiffening the steel superstructure and adding a water barrier.

The academy said the chapel has leaked since it was built and previous repairs failed. The restoration was expected to cost between $58 million and $68 million, the school said last year.

The chapel, a National Historic Landmark, is a striking, triangular-shaped structure that stands 150 feet tall.