The less than perfect conditions of the Scuderie building (Quirinal Stables) and the desire to turn the building into a museum called for a decision to undertake significant restorations. The project was entrusted to the renowned Italian architect Gae Aulenti and overseen by Rome 's Superintendent of Architecture. It has allowed the city to recover a strategically placed architectural gem and puts to excellent use a building that, for its history and its dimensions, represents an exhibition space of inestimable value.
The initiative that eventually led to the complete restoration of the building was launched on February 20, 1997, when the Office of the Italian President conceded use of the Scuderie to the City of Rome. On July 10 of that year, the City entrusted the “Agenzia per il Giubileo” (an agency charged with overseeing events to celebrate the Jubilee Year) with the management of the seventeenth century building. After two and a half years of work, on December 21, 1999, in the presence of the President of the Italian Republic , Carlo Azeglio Ciampi, the first exhibition was inaugurated, with a series of masterpieces from the Hermitage museum in St. Petersburg .
In adapting the Scuderie to the demands of a museum, the utmost respect was maintained for the building's history. So as not to damage the original structure, a series of plasterboard walls were raised in the two large galleries on the second and third floors. Not only do these walls provide a surface on which to hang the artwork, but they serve to hide the sophisticated network of cables and tubes that supply the building's heating and air-conditioning, security system, and lights. Some 66.5 kilometers of electric wiring, 2 thousand meters of air ducts, 6 kilometers of steel tubes, and 14 thousand meters of cables run behind those walls. There are 530 sensors to maintain a constant temperature and 270 light racks, designed by Gae Aulenti with the lighting designer Piero Castiglione.
Natural materials were used for the floors: travertine marble on the ground floor and oak parquet with a gray gloss on the second and third. The old flagstones were conserved, but are covered to keep visitors from tripping and to eliminate any architectural barriers. A lime wash was used on the walls in accordance with Roman stucco-work. For the exterior, the architects chose to remain faithful to colors applied in 1865: the two-toned facade was painted in the color of travertine and burnt raw umber. Broad research and laboratory tests were undertaken – under the guidance of the Istituto Centrale per il Restauro (Central Restoration Institute) – to find the most authentic of hues. For security reasons, Gae Aulenti was forced to create an extra stairway between the second and third floors, so she designed an external, glass-covered passage, which offers visitors a glorious view of ancient ruins and the city of Rome .