The expansion of The Queen's Gallery is the most significant addition to Buckingham Palace in 150 years. The £20 million project has been funded entirely by the Royal Collection Trust. 

In 1997 a limited competition was held for the appointment of an architect to expand and modernise the existing Gallery. The opportunity was also taken to refurbish the Victorian kitchens below.

The Gallery brief was to upgrade the outdated air-conditioning, to improve physical access and public services, and to provide a more flexible and intelligible series of exhibition spaces. John Simpson & Partners were appointed project architects in 1998. 

In adding new galleries and associated spaces, John Simpson has had to work within the complexities of an existing building, as remodelled after Nash's time by Blore, Pennethorne and Webb.

Each architect continued the strong classical language of Buckingham Palace, and Simpson has chosen to respond to this in an imaginative and sympathetic manner.

Particular challenges were to provide a bold new entrance to the Gallery and to resolve the awkward external junction between the Victorian buildings and the 1980s police accommodation above the old shop. 

A new screen wall has been created between the Gallery's entrance hall and display areas, which replicates the original wall of Pennethorne's scheme and completes the Palace's garden façade.

Containing three-and-a-half times more display space, the new Queen's Gallery is approached through a striking portico leading to a soaring double-height entrance hall and staircase. A multimedia room provides space for computer kiosks, which can be used independently of a visit to the exhibitions. They provide information about items in the current display.

On the upper level of The Queen's Gallery there are seven galleries or rooms, used in a variety of combinations, for special exhibitions of paintings, prints, drawings and watercolours, furniture, porcelain, miniatures, enamels, jewellery and other works of art. The new public areas on the first floor include education and lecture rooms for a range of events.