Vogue contributing editor Robin Muir's eighteenth-century country house in the South Downs

Having a hectic work and social life in London, Paul Lyon Maris and Robin Muir had long searched for a weekend retreat within easy reach of the capital, with no light pollution and, more importantly, no noise from either traffic or other irritants. Happily, they found the house that fitted these exacting standards one wet New Year's Eve, when visiting a friend whose house it then was. 'We arrived in the dark and immediately had this immense feeling of warmth and welcome,' explains Paul. 'It was clearly in a beautiful spot - the house is approached down a very long lane - and I jokingly suggested that if she ever thought of selling, she should let us know, and she did. It was all cream and white linen when she had owned it, and beautiful. Then we arrived with horses and five dogs.'

Built in 1770 in local flint and surrounded by the rolling farmland of the South Downs National Park, the house had been two separate keepers' cottages - one of the keepers still takes his walk along the lane each day - until 20 years ago, when it was converted into a single residence.

With its one-room-deep layout, a small hall and corridor and single-storey kitchen added on at a later date, the cottage, although cosy, did not suit their needs, they realised - particularly should they one day decide to make it their main home. However, rather than make additions at different, unsettling stages, they sensibly waited until they could afford to do everything at one time. As Paul says, 'The cost of such work being so high, it was far more palatable to do the whole thing in one fell swoop.' They asked decorator Caroline Holdaway, who had previously worked with them on their house in Primrose Hill, to help them.

'In our preliminary discussions,' Caroline explains, 'we were conscious that the cottage - with its low ceilings, series of small rooms and equally small windows - would essentially always be a cottage. However, it needed to be enlarged and made more spacious, with good-size entertaining areas, a kitchen large enough to sit in, with direct access to the garden, plus space for studies and spare rooms, and boot and utility rooms. From the beginning, I had an image of a glass structure linking the old and the new, but was not sure how to make it work.'

Caroline frequently works with Mike Etchingham, an architectural technologist, and he determined a practical and spacious layout that would retain the essential charm of the cottage. Demolishing the single-storey kitchen extension, he replaced it with a two-storey extension for a large drawing room with a spare room and bathroom above, with access through a glazed area originally part of a courtyard. This immediately achieved more space and opened up the hall and corridor, making better circulation for entertaining and allowing Paul and Robin to feel, on rainy days, that they were outside in the landscape, while enjoying the warmth of an armchair and a good book.

While plans were drawn up and permissions sought, Caroline, who is a master at sourcing materials from salvage yards, set about finding suitable pieces - a process that took about a year. 'We wanted the new extension not to be a pastiche, but to feel lived in and respectful of the older part of the building,' she explains.

The first item found was the Georgian staircase that now leads from the double-height hallway, its flat ceiling having been removed, which gives, on entry, an immediate feeling of space. The beautiful elm floorboards downstairs took some finding, as did the ancient ceiling beams, hollowed out to conceal steel structures throughout the house.

MAY WE SUGGEST: British Vogue archivist and editor Robin Muir's deliciously inviting home