But the increased outdoor space, converted from indoor space, can lead to lower energy bills as there is less home to heat.

WSJ: Full Enclosure - WSJ Mansion

The Grade II listed Time Office, which incorporates an Art Deco clock tower, has already been converted into office space.

BBC: Terry's chocolate factory in York starts to be demolished

The day after the river outing, Bragdon is back at work in the Metro building, a former Sears department store converted to office space in the Rose Quarter of Portland.

CNN: Polluted rivers stain Portland's image