Max Rollitt adds Soanean elements and a 'patina of age' to an overly modernised house

If this four-storey house in a west London square hadn't been rocked by a World War II doodlebug, it would have been listed like its neighbours, restricting what the current owner could do to its interior. Not that she wanted to take liberties. "She was keen that it should be restored to its period,' says the designer, Max Rollitt, 'though it didn't have to be an exact restoration. The staircase had sunk quite a bit and the architect decided all the floors had to be taken out, top to bottom-so the challenge was to put everything back in a way that didn't look over-restored.

The house's presiding spirit is Sir John Soane, for whom the owner has a passion. His influence can be seen in everything from the arrangement of the rooms to the mouldings (copied from designs in the Soane Museum) and the principal doors – ‘made flush in the Soanean manner,' Max explains, 'using mahogany from antique table leaves to get that thick veneer, with ebony-line details'. Similar ingenuity was essential to provide enough storage for a family of four in a comparatively narrow house. As the owner says, ‘Max is clever at creating a lot of space out of nothing, and giving you something which is both beautiful and functional.'

As you enter through the front door, the owner's love of art is immediately apparent: the hall acts as a gallery for her collection of Dürer prints. Turning right at the stairwell, you find yourself in a second, smaller hall, this time dominated by John Rocque's enormous eighteenth-century map of London, hung above a mahogany bench. It's not the kind of room you would expect to find in the city, and looking right and left you realise that it's part of an enfilade – a common feature of Soane's country houses. This was created by knocking through to the dining room, which overlooks the garden square - on one side and a kitchen extension into the back garden on the other. A Thirties French chandelier in the shape of a galleon lends humour to the dining room; an array of sconces on one wall, displaying small china pieces by Wedgwood, is another unusual touch.

The kitchen extension involved removing the Georgian rear window, but rather than discarding this, the owner used it to replace a smaller one in the upstairs drawing room. 'So much of what we've done has been about preserving what is beautiful about the house,' she says; for example, the slightly wonky staircase and the windows with their original shutters.

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In the drawing room, which occupies the whole of the first floor, only the chimneypiece and the windows have survived the refurbishment – though you would think that most of the contents had been there for decades. “We've tried to make it look like a home that has evolved over time,' says Max, who either sourced or made all of the furniture. 'I like things that have a patina of age – the refined beauty that comes from use and sunlight and being loved. Among the most notable pieces are a Chippendale Junior sofa, upholstered in Claremont brocade, and a mahogany card table that rotates and folds into a side table.

A battle scene by the seventeenth-century Flemish painter Pieter Snayers takes up most of one wall, while the work of two Irish artists, Jack Yeats and Paul Henry, is displayed around the corner of the L-shape room.

The walls have been painted grey, using a lime-based paint custom-mixed by Naismith Robertson that enhances the lived-in look, 'It's got a wonderful textural feel, so you don't mind the odd scruffed-up bit,' says the owner. 'It looks different according to the light, and works particularly well in the stairwell, pulling together a lot of different spaces and weird angles.'