Clarence House was built between 1825 and 1827 to the designs of John Nash as the new London home of George III’s third son, Prince William Henry, Duke of Clarence and his wife Adelaide. The house incorporated the south-western corner of the Tudor buildings of St James’s Palace.
The house created by Nash was a bright, stuccoed mansion of classical proportions. Facing west on to Stable Yard Road, it had three storeys above a basement and a hipped slate roof. There was a double portico at the centre of the new west front, leading to the entrance hall (now the Library), which in turn connected with a long corridor or gallery running the whole width of the house. To either side of the entrance hall, Nash created a Breakfast Room (now the Morning Room) and Dining Room, with three principal reception rooms directly above on the first floor.
The interior of Clarence House was plain in comparison to Nash’s designs for Buckingham Palace. Ornamental plasterwork was confined to the reception rooms on the first floor, which were hung with crimson damask.
Nash made numerous alterations to his original plan as work proceeded, and the final cost of £22,232 was more than double what he had originally estimated.