Construction was of bricks fired on site, stuccoed and lined out to resemble ashlar, with details such as the porch in Horsham stone. The fire of 1904 reduced all but the servants' quarters to a roofless shell, destroying virtually everything, including a prized collection of Raphaels, Holbeins and Vandykes, a fine library and many important manuscripts. Among items valiantly rescued by the head coachman and footman were an escritoire containing important correspondence, some family portraits, and the safe (although Lady Burrell's jewels, with the exception of her diamonds, were ruined by the "terrific heat").
After a narrow escape with his wife and month-old son, Sir Merrik Burrell commissioned a full rebuilding of Nash's castle. Rather remarkable
for its time, this £18,801 restoration was carried out almost immediately, a three inch thick leather bound schedule of works testifying to the exacting quality of the work by Longleys. "The loss of my home was a great sorrow but the rebuilding of it has been quite a pleasure thanks chiefly to the way in which you carried out the work" wrote Sir Merrik to Mr. Longley in July 1905. Under the influence of the architects, A W Blomfield & Sons, an Arts & Crafts aesthetic crept in, particularly in the library, and the new third floor bedroom wing. But Nash's decorative plasterwork was replicated by Jacksons using surviving fragments, so that the rooms today retain their Gothick friezes and cornices [decorated with tiny goins and cusped interlacing tracery].
In the 1930s A V Heal made various alterations, including the addition of a half bay window in the master bedroom, which was subdivided to accommodate a huge Art Deco bathroom. This has now been removed, along with the Tudor bed and panelling installed by Viscountess Cowdray in 1931 while Sir Walter Burrell and her granddaughter, Judith Denman, were away on honeymoon.
Nash's strength at Knepp, as with all his houses, was not a scholarly attention to detail, but the relationship of architecture to setting, and his geometrically composed sequence of generously-lit rooms. These open off a long, central axis of vestibule, hall and lobby, with an impressive circular staircase ascending a tower with a great gothic window at the far end. The loosely gothic interiors have leant themselves well to the introduction of contemporary colours and fabrics, and the boldness of other changes made in collaboration with the designer Chester
Charles and Isabella Burrell moved into Knepp in 1988/9, but waited nine years before starting to reorganise and update the house. It was painted "hospital green or magnolia" throughout, and cluttered with Tudor oak furniture, much of which they have now sold. "It had become very Edwardian and dour - like an abandoned boarding school" says Mr. Jones, former managing director of the decorative design business at Colefax and Fowler, which was owned by Mrs Burrell's father, Michael Tree. "I wanted to put some humanity into the place, and the only way I could do it was with a measure of irreverence", he says, and his grained niches with trompe l'oeil gothic panels, and overscaled library curtains reflect this playful attitude.
He rescued from an upstairs passage a "charmingly pretty" early Victorian portrait of Lady Fanny Burrell and, relishing the incongruity of its writhing Roman rococo giltwood frame, hung it over the master bedroom fireplace: "It was so refreshing to find it amidst all that Gothic revival and Arts & Crafts; like cool springwater in a desert." He painted "gloomy oak doorcases" in "knocked-out" white, and stippled the hall and landing "Fowler yellow" and cobalt blue - "not serious castle colours".
Mr. Jones's modernist streak is at once apparent on entering the hall, one of the most original of the recently redecorated spaces. Here, the museum effect of Charles Burrell's collections of seed pods and insects displayed down a long central table, with tribal weapons and framed vellum estate maps dating back to 1554 on the walls, is counterbalanced by modern soft furnishings against the ochre, burnt orange and muted greys of the walls, stair carpet and stairs. Loose cotton covers mask the tapestried upholstery of three antique sofas, and a circular stairhall carpet by Sandy Jones echoes the primary colours of spherical patterned cushions made by prisoners for the charity Fine Cell Work.
One significant element in the redecoration of Knepp has been the introduction of paintings and furniture inherited by Isabella Burrell, a travel writer and granddaughter of the famous decorator Nancy Lancaster. The oak panelled library, now updated with a Purbeck marble chimneypiece carved by Emily Young to Mr. Jones's design, and a dark and light striped carpet by his wife Sandy, has been hung with a fine collection of paintings by artists such as Augustus John, Graham Sutherland and Lucian Freud. A feature of the drawing room, which the Burrells have rehung with a dusky pink double damask wallpaper from Colefax and Fowler, is a pair of red velvet curtains from Ditchley, Mrs Lancaster's home when she was married to Ronald Tree. Also from Ditchley is a beautiful George I bureau cabinet in the master bedroom, and the fourposter bed used by Winston Churchill whenever he stayed there.
Mr Jones's stylish blend of old and new has given a subtle lift to the bow-ended dining room, with its portraits and Classical chimneypiece (one of several imported from Ireland in 1905). He has offset an exotic Kirman carpet, formerly in the library, with a muted palette of cream-painted timberwork and earthy shades, the Morney wallpaper being a simplified version to his design of an early 19th century paper in the Yellow Room at Badminton, based on a Tudor strapwork pattern by Thomas Willement. New, ogee-backed chairs capture the mannered gothic spirit of an 18th century original, from which they were copied.
Mr. Burrell's office, on the site of the old laundry, has been created by reinstating a ceiling removed in the 1930s to make a squash court. Its Classically inspired, overscaled bookcase was designed by Mr. Jones to capture the character of estate office furniture - robust but unpretentious. He created the present kitchen from a passage and butler's pantry, with a new bay window opening onto a lawn shaded by a Cedar of Lebanon. Art Deco sunloungers have been copied from originals formerly at Mirador, Mrs Lancaster's family plantation house in Virginia which is depicted in a series of watercolours now at Knepp.
Remarkably, given the noose of A-roads that surrounds its green acres, Knepp's beautiful landscape remains unspoilt. It is home to the country's 4th largest polo club, with eight polo grounds that can be hired for sponsored events. Nash's sprawling plan has leant itself well to modern use; today the estate is run as a fulltime business from a former service wing converted to offices.