Under the direction of its current occupants and leaseholders, RIT Capital Partners plc, Spencer House has been the object of one of the most ambitious restoration projects to be undertaken this century. The House has now been restored to its original splendour and is used partly as offices and as a place where entertainments can be held in the historic setting of the state rooms.

A team of architects, engineers, designers and historians were drawn together for this unique project. Architecturally, the House has been restored as far as possible to its original late eighteenth-century appearance, retaining Henry Holland's alterations of the 1780s and 1790s, rather than as first completed in the 1760s. Holland, a major English architect, had played a particularly significant role in the buildings development.

The Spencer family last lived in the House in 1926, they then let the building to a variety of tenants. As a result, the state rooms were used as offices from the late 1920s until 1985, when RIT Capital Partners plc acquired the lease.

The restoration, begun in 1987, was as complex a project as the building's original construction and was largely completed by November 1987.

All the principal rooms, some of which had been subdivided, were painstakingly restored and their missing original fixtures including the chimneypieces, doors, chair rails, skirting mouldings and architraves were carefully copied from the originals which had been removed by the Spencer family to Althorp in 1942, at the height of the Blitz.

Working from paint-scrapes and documentary evidence it was possible to determine the original allocation of colour and gilding in the state apartments and, therefore, to recreate accurate decoration of the principal rooms. The missing carved architectural detail was replicated by Dick Reid, the York-based mastercarver, and his team of craftsmen and the quality of work rivals that produced in the eighteenth-century.

Appropriate paintings, sculpture and furniture have been bought to furnish the state rooms. Other works have been borrowed from various sources, including the Royal Collection, The Royal Academy, the Tate Gallery and Temple Newsam, as well as private owners and dealers. Restoration of the House has enabled the return of some of the key pieces of furniture to their original locations, including Vardy's elaborate giltwood console tables in the Dining Room and the return of Stuart's Painted Room suite, both on loan from the Victoria and Albert Museum.

Work on Spencer House continues, with appropriate late eighteenth-century replanting of the garden. The decoration of the state apartments constantly evolves as fresh opportunities arise both to purchase and to borrow appropriate furniture and works of art.

In architectural terms the project has been hailed as one of the most successful ever undertaken. Now, as in the eighteenth century, the state apartments provide a magnificent showcase for works of art and furniture and serves as a place of business and a focus of social, cultural and political activity.