The architect Robert Adam described Kenwood as "a beautiful villa belonging to Lord Mansfield, the friend of every elegant art and useful science". The villa, remodelled by Adam in the 1760s and 70s, stands in 74 acres of landscaped gardens and woodland, affording fine views towards the City of London.

Adam’s adaptation from 1764 to 1779 of an existing building for his client, William Murray, 1st Earl of Mansfield, led to the addition of the impressive colonnaded portico on the north front, and the celebrated south front (and terrace).

On the west side of the house is an orangery, probably built in the 1740s by Lord Bute. Adam’s addition of the library or 'Great Room' to the east of the south elevation, with the same volume as the orangery, was an ingenious way of providing a symmetrical façade.

The two wings to the north-east and north-west of the house, providing a dining room and a music room, were added in the 1790s by George Saunders for David Murray, 2nd Earl of Mansfield, who wished to adapt Kenwood from a villa into his main family residence. The 2nd Earl was also responsible for the addition of the service wing on the eastern side, which was cleverly hidden by his new dining-room wing.

Adam had applied stucco or ‘Liardet’s cement’ to the exterior, which had failed and caused severe problems. This contributed to the 2nd Earl’s decision to face the new wings in white Suffolk brick, thus distinguishing them visually from Adam’s work. The stone colour in which the 2nd Earl had the wings painted was revealed through paint analysis and was recreated in 2013.

Despite the symmetry of the exterior, the proportions of the rooms are modest – particularly the Entrance Hall, which doubled as a dining room. This was partly disguised by Adam’s decorative scheme throughout the house, with an integrated colour palette and ceiling designs.

Many of the ground floor rooms retain Adam's original decorative schemes, including carved marble fire surrounds, stucco work, and decorative ceiling paintings by the Venetian artist Antonio Zucchi. The Library or 'Great Room' at Kenwood is widely acknowledged as one of Adam's finest interiors.

Following an extensive repair and conservation project begun in 2012, part-funded by the Heritage Lottery Fund, Kenwood reopened in late 2013. Work included repairing the Westmorland slate roof and redecorating the exterior and interior of the house, based on new paint research into Adam's original scheme.

The south front rooms have been much altered since Adam’s original redecoration of the 1760s and 1770s. Most recently, in the 1920s, they were converted for use as an art gallery for the Iveagh Bequest.

The collection, comprising internationally significant Old Master and British paintings by artists including Vermeer, Rembrandt, Gainsborough and Reynolds, has now been rehung. The rooms have been refurbished to represent ‘the artistic home of a gentleman of the eighteenth century’, as was the wish of Edward Cecil Guinness, 1st Lord Iveagh.

To mark the 350th Anniversary of the death of Rembrandt van Rijn in 2019, the artist’s celebrated masterpiece Self-Portrait with Two Circles will be the subject of a special temporary display at Kenwood. Rembrandt #nofilter will be open free of charge from Friday 20 September 2019 until Sunday 12 January 2020.

Though the original contents of the house were sold by the 6th Earl of Mansfield in 1922, Kenwood is today home to a significant collection of eighteenth century decorative arts, including works by Boulle, Vullimay and Roubiliac. Several important items of furniture designed by Robert Adam for Kenwood have also been returned to the house and are displayed alongside significant pieces made for other sites by Adam and his contemporaries.