It's called everything from facadism to facadectomy, and it often means only a building's shell is saved.
1985 — James T. Bratton, "We should 'preserve' Dallas'", The Dallas Morning News, 4 January 1985:
A new building might be more efficient from a space-planning standpoint; but, I cannot believe that there are not creative architects in this city who wouldn't welcome the challenge of designing new, efficient space while preserving at least the shell of the Metropolitan. (As a last resort, I will make the concession for a facadectomy.)
1998 — Katherine Jensen & Audie L. Blevins, The Last Gamble, University of Arizona Press (1998), →ISBN, page 124:
Preservation, at least of commercial properties, in these Colorado towns is best described by the rubric of facadism or what Wallace called "facadectomy or facadomy," referring to redevelopment that tears down old buildings entirely, except for their streetfront wall, leaving little more than a historic veneer.
1999 — David Dillon, The Architecture of O'Neill Ford: Celebrating Place, University of Texas Press (1999), →ISBN, page 133:
The plaza and two of the Ford Powell & Carson buildings were completed, with the theater facade retained as a stage set entrance to the retail and plaza cafe areas. […] Even Ford Powell & Carson finally conceded that the facadectomy was a weak political compromise, though it blamed the Conservation Society for showing bad faith in the negotiations.
2004 — AIA Guide to Chicago (ed. Alice Sinkevitch), Harcourt (2004), →ISBN, page 106:
Chicago's largest "facedectomy" was performed here in response to public outrage at the proposed destruction of the McGraw-Hill Building. More than 6,000 pieces of limestone were removed, cleaned, and rehung on a new steel frame structure.
2005 — Robert Morris Skaler, Society Hill and Old City, Arcadia Publishing (2005), →ISBN, page 94:
The building was demolished around 1974, but the façade was preserved by a "façadectomy."
2011 — Ellen Dunham-Jones & June Williamson, Retrofitting Suburbia: Urban Design Solutions for Redesigning Suburbs, John Wiley & Sons (2011), →ISBN, page 76:
For example, when the owner of Saint Andrews, a failing strip mall, presented his plans for a "facadectomy," the office asked, "Can we help and play with it?"
2011 — Sharon Haar, The City as Campus: Urbanism and Higher Education in Chicago, University of Minnesota Press (2011), →ISBN, page 168:
In the end, twenty-one facades were saved for redeployment — a "facadectomy" — in a main street design that evokes nineteenth- and early-twentieth century architecture through materials, detailing, and streetscape furnishings.
Noun: "(architecture) the removal and replacement of a building's facade"
1994 — Stewart Brand, How Buildings Learn: What Happens After They're Built, Viking (1994), →ISBN, page 19:
Demographer Joel Garreau says that in "edge cities" (new office and commercial developments on the periphery of older cities) developers are accustomed to fine-tune their buildings by changing rugs and facades — a typical "facadectomy" might go upscale from pretentious marble veneer to dignified granite veneer to attract a richer tenant.