BARNHOUSE FARM has quite a claim to fame: it was one of the first barn conversions in Britain – possibly the first. The earliest record of the house, in 1499, names it as “Barnhouse”, implying that it was either a barn converted to a house or a house built like a barn.

Either way, enchantment awaits as I turn up the half-mile drive to the property, near Horsham, West Sussex. Before I have gone 50 yards, I see three wild deer through the hedge, grazing contentedly. “They’re often there – they’re almost tame,” says the owner, Jane Grinling, a painter, who bought the house ten years ago with her husband, Gavin, an architect. “On the other side of the drive we’ve had three mares with their foals all summer.”

This part of Sussex is ravishingly beautiful in early November, with leaves of russet and gold in the trees that line every field and hedgerow. Even so, £1.65 million seems a lot to ask for a house with five acres in this present uncertain market. But the agent, Jackson-Stops & Staff, declares simply: “So many people looking around here and so few houses to show them!”

Barnhouse Farm, which is Grade II* listed, is an oddball among timber-framed houses, having none of the first-floor overhangs usual in Kent and Sussex. Instead the walls are of square frame construction with a pretty, pink herringbone brick infill. The first floor has close studding: vertical timbers packed like Guardsmen on parade. The best front of the house looks down to the pond with three gables and intriguing triangular windows over the shallow Tudor arched doorway. The roof has massive Horsham stone slates.

A neat hornbeam hedge lines the approach, and white flowering japonica along the garden front is underplanted with grey-green lady’s mantle. On the east front, purple iris is planted right against the house. On the field behind the house, the owners of the Knepp Castle estate graze their polo ponies.

Annabelle Hughes, a local house detective, has compiled the house’s history through hearth tax returns, wills and probate inventories. Her most likely scenario is that the house was completely refloored in the 1580s. Mrs Grinling – who paints under her maiden name, Jane Cattlin – likes the result. “The advantage of a barn is that ceilings are much higher than in most timber-framed houses,” she says. Upstairs the ceilings have been raised above the beams to gain still more headroom.

The two ground-floor rooms have a massive timber beam running through them, with neat rows of floor joists notched in. At one end the timbers are on a different pattern, suggesting that this was the site of an earlier stair. The living room has a very broad, deep hearth with a timber lintel. Inside is an unusual beehive dome over the fire. “I thought it was rather ugly at first, but it retains the heat magnificently,” Mrs Grinling says, patting it affectionately.

About 20 years ago, the timbers and herringbone brickwork at the north end were entirely renewed under the supervision of English Heritage, but a mellow Tudor oak door and a doorway with a characteristic shallow arch have been incorporated. In turn, the Grinlings knocked down an ugly double garage and Mr Grinling designed a new wing with a granny flat and artist’s studio. A link building contains a new hall and a kitchen that overlooks the garden.

As I leave, a huge 4x4 is powering up the drive. Sure enough, it’s another eager viewer – despite that price tag.

For a tour of some of the best country houses in Britain, go to: timesonline.co.uk/marcusbinney

FACTFILE

WHAT YOU GET: Grade II* listed house in five acres. 3,629 sq ft.

WHERE IT IS: In Shipley, West Sussex, eight miles from Horsham and Pulborough, 12 miles from Worthing. Trains from Billingshurst, three miles away, take just over an hour to London.

PRICE: £1.65 million, through Jackson-Stops & Staff, 01730 812357, www.jackson-stops.co.uk

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