Don't judge a book by its cover, and don't judge an 1894 Capitol building by its 1954 decor. You never know what's beneath the surface.

A serendipitous request for radiator maintenance led to the overhaul of the Colorado State Capitol’s interior, returning House and Senate chambers to their original turn-of-the-century glory.

The project, which wrapped up in 2016 after three years of work, revealed and refurbished stenciling that had been covered since 1954. It also restored the chambers’ chandeliers and uncovered skylights from the building’s original design.

Apparently, nobody knew what lay behind the drab acoustical tiles that had been in place for over 50 years, though historic photos pointed to its regal past. It wasn’t until 2011, when former House Speaker Frank McNulty requested a fix for a crooked radiator cover, that the layer of beige was first peeled back, revealing the original filigree stenciling by Denver artist Manuel Hill. It turned out the House chamber had previously been painted green and the Senate red.

It’s unclear who exactly was responsible for the regrettable decision in 1954, but Nan Anderson of Anderson Hallas Architects—the Golden, Colorado-based firm that undertook the restoration—has her theory.

“Some legislator no doubt wanted to hear himself better,” she says. “There were these hideous 1950s acoustical tiles that someone, in their great wisdom, had plastered everywhere. They kind of scratched the surface a little bit and found what was beneath. And the rest is history, or the recreation of history.”

Almost as bad as the tiles themselves was the way they were installed. Four large dollops of horse glue were applied directly to the original surface for each two-foot by two-foot tile. Contractors tried ice, a heat gun, and chemical applications before finally settling on water and hand-rubbing as the best way to remove the glue.

Close inspection of the stencils then revealed even more when one of the contractors found more patterns behind the 1905 surface. An infrared camera was brought in from the Denver Art Museum, and the designs—of animals, shields, and historical figures that must have been added between the building’s completion in 1894 and 1905—were documented, though time constraints prevented the team from conducting much additional research.

Despite the glue, the tiles helped in one way by essentially freezing the stencils in time, largely protecting them from 50 years of potential degradation.

“It really looked pretty bad, but in a way they preserved what was behind it,” says Lance Shepherd, Manager of Design and Construction Programs at the Colorado Office of the State Architect. “Once we started taking the tile off, it was just a matter of removing the glue and cleaning it up.”

The architects conceded that the audial concerns weren’t totally unfounded, and on the upper level the stencils were carefully replicated atop new acoustic panels under the supervision of the preservationists at History Colorado.