Oasts come in all sizes, some with multiple kilns or ‘kells’ as they were once called, some with square kilns and some with circular kilns, the latter introduced when it was thought, erroneously, that they would be more efficient.

More efficient or not, the circular kiln oasts have provided the more attractive exteriors and the more interesting living spaces. Architects, however, have always had varying degrees of success in their conversions and owners equally varied success in decor and furnishings. Modestly sized circular rooms are often far from simple to handle with much-loved pieces from previous homes often either seeming out of place or simply hoovering up footage as their rectangular forms carve circular segments out of the available floor space.

Some oasts, however, begin with all the prerequisites of a practical and attractive living space and both architect and owner realize their potential with professional skill and personal imagination. Marlingate Oast on the outskirts of Goudhurst, built in the 1880s, is just such an oast.

When the triple-roundel oast was bought three years ago by professional photographer Katy Donaldson and her husband Jim, it had already been converted with considerable flair and although they had some 1980s touches to get their teeth into, the essential interior spaces and layout was excellent. “To begin with we were lucky in that the roundels were both a decent size and height,” says Katy. This immediately offered six good-sized rooms – three bedrooms, a kitchen, utility and a dining room. The architect, however, had also realised the potential of the height of the roundels to the full when it came to the hallway, by creating a two-storey hall and galleried first floor. Above the head of the stairs is a window into the curve of one of the roundels. “We think it looks a bit like a boat as you look up the stairs,” says Katy. And so it does, adding the finishing touch to the large bright space that greets you as you come in through the front door.

To the left is the original pressing and bagging section of the oast, now the drawing room with French windows out into the garden. The original beams remain as do the previous owners’ curtains. “The curtains were so good I just couldn’t lose them – which meant I had to match them with a pale green sofa – not something I would otherwise have considered,” says Katy.

Against one wall is her son’s piano and against another a heavy 28-draw chest that came with the family back from Dubai where Jim had been working. “Originally, it was dark wood but that would have been totally out of place here, so I painted it white,” she says. The two low tables – also from Dubai – received the same treatment. Gone is the 1980s brick fireplace and in its place stands a woodburner which will ultimately be surrounded by a stone fireplace.

The 80s conversion originally provided a second door into the drawing room but Katy’s dogs drove everyone nuts with their tearing figures of eight in and out of the hall so it was blocked up and replaced by an understairs bookcase. The staircase itself was a 1980s pièce de résistance with open treads and so this was duly boxed in. Opposite the stairs stands a large woodburner that remains on throughout the winter providing heating for both the hall and upstairs gallery.

Katy has changed the function of all three ground floor roundel rooms creating a utility room, kitchen and dining room. All were laid bare and begun again from scratch. The kitchen required the most planning and the solution of bespoke units built to order by Dave Newing, of Millside Joinery in Lenham, has made the absolute maximum of the circular wall space while creating a room that never for a moment seems cramped or cluttered. “Dave did a really excellent job and I wouldn’t hesitate to recommend him,” says Katy. Dave’s units and dresser surround a central marble-topped preparation table – Katy brought the marble back from Greece where she sourced it from the Pentelic quarries of Mount Pentelikos which also once provided the marble for the Parthenon – and had the base made from reclaimed pine.

Originally the dining room roundel was accessed solely from the hallway but Katy has provided additional access from the kitchen. Here Katy has accentuated the space and height of the roundel by keeping furnishing to a minimum, just a wine rack and shelves to display her collection of glasses. “I don’t have any matching glasses,” she says. ”I think it’s more interesting to have a range of different glasses – some are cheap and cheerful, others hand-made by artists.”

Upstairs, there are four bedrooms – three for the family in the roundels and a fourth in the barn section of the house over the drawing room. Her daughter Daisy’s room is a pastel blue. “She wanted the whole room dark blue but we negotiated her down to just the window frames.” The windows in all the roundels are superb, virtually floor to ceiling, and look out over some lovely views.

Her son Tom’s room is deep red, very much a boy’s room and currently shrine to Tin Tin, a legacy of the family’s time in Brussels. Above is a playroom with a glass ceiling and a view right up through to the roundel vane. The master bedroom is dominated by a huge bed with tubular steel head and foot, another Dubai find. Katy has completely revamped the two bathrooms and knocked down a wall to create an en suite for the master bedroom.

The oast stands in some three acres of garden, paddock and, until recently, an orchard of 40 apple trees. “What do you do with that amount of apples?” asks Katy. “Nobody wants them and there’s a limit to just how much apple sauce you can make.” The orchard has now been reduced to four trees but some 100 silver birches have been planted so environmental fair exchange is no robbery.

Running a home and a business, Katy found keeping up the garden a major drain on any remaining time but help was at hand in the shape of Richard Sime of RJ Garden Services in Marden. “Three acres doesn’t sound too much but it still takes an incredible amount of time to keep in order,” says Katy. “Richard is absolutely fantastic and is someone else I wouldn’t hesitate to recommend.”

Katy’s pride and joy is a spectacular vegetable patch which is the home to onions that appear to have escaped from a fairytale so large are they. Close to the house is an outbuilding that Katy has converted into a photographic studio from which she runs both her portrait, photography and her highly successful greetings card business Dipingo Design, which she runs with her business partner and friend Lianne Streek.

“Lianne is the commercial and business arm of the enterprise. whilst I am the creative department!” says Katy. The company was launched at the beginning of 2010, and already supplies retail giants such as Liberty and Fenwick. In addition to Dipingo’s own card range which is now available as far afield as Australia, Katy also designs original and exclusive items for businesses and charities along with personalised cards for family occasions and Christmas.

Oasts may not always provide the ideal living space but when this amount of flair has gone into their initial conversion and subsequent décor, there are few such iconic buildings that can provide such a lovely family home.