Soon after moving into the White House in 1945, President Truman noticed large areas of cracking in the plaster throughout the house. A structural survey revealed major problems caused by stress from the 1902 floor-bearing steel beams and the weight of the third floor and roof, all pressing against the inner brick walls. In 1948 Truman appointed a Commission on the Renovation of the Executive Mansion that decided to retain the original walls, the third floor and the roof, while removing and then reinstalling the interiors within a skeleton of steel structural beams on a new concrete foundation. In the end, little of the 19th-century or early 20th-century interiors were retained. Two levels of subbasements, and service areas under the North Portico were constructed, and the Grand Staircase was substantially changed. Of the state floor rooms, only the State Dining Room walls were reinstalled, but then were painted.
A swimming pool installed in the west terrace for Franklin D. Roosevelt in 1933 is replaced by the press center. A porte cochere is also added to the north side of the west wing.
Since 1952, attempts to provide a sense of past history of the President’s House and new research have resulted in decorative interior changes but no substantive architectural work. The preservation of the historic house and its contents has received high priority. Beginning in 1978, a study was begun to assess problems with the exterior paint. Successive layers–in some areas as many as 40–have been removed from each of the exterior walls. Following the removal of the paint, masons began repairing stone which had deteriorated over time.
As the restoration of the stone walls of the White House entered its late stage in 1988, the White House in cooperation with the National Capital Region of the National Park Service and the Historic American Buildings Survey (HABS) began a five-year documentation project to record the exterior elevations as part of that project completed in 1993.
In 1990 the American Institute of Architects in cooperation with the White House Historical Association sponsored HABS to record the interior architecture of the White House. The results of these two completed projects combined to create a comprehensive record of the historic main house. The updated drawings will be used for base documents for future renovation, restoration, maintenance, and interpretation of the house.