TRAVEL When architect Geoff Hull first stepped onto this old government office site on London’s Whitehall eight years ago, he found it in a hazardous state. He stumbled on everything from waterlogged basement flooring to air-conditioning ducts artlessly rigged down the center of corridors, an ad hoc solution that had defaulted to permanent. The stringent historic protectionism he was tasked to work within, known in the U.K. as listing, had seemingly not been applied by the government to its own Old War Office (OWO), a landmarked Edwardian-era building commissioned in 1898 and, famously, Winston Churchill’s office during WWII. “I could see the grandeur, the importance, but it was disappointingshocking, even—what the government had done to the building,” says Hull, a director at EPR Architects. Nonetheless, he says, “it was one…