A farmhouse restored with soul by Maria Speake of Retrouvius

The first sight of this Georgian farmhouse in the Chilterns left the architect and designer Maria Speake despondent. 'A very ugly, Edwardian-style entrance had been tacked on in around 1906, making the house into an L-shape,' she says. This addition spoiled the symmetry of the original house and didn't add much useful space. Once inside, things were no better: 'The hall felt like a cold corridor and the place felt cramped, not like a big house at all.'

Maria decided to fill in the gap in the L-shape. On paper, it was a tiny extension, though it involved making a completely new roof and giving the house a longer façade. But the benefits came in a larger, more welcoming hall and a huge, handsome sitting room - just perfect for family life. And family life has been a strong bond between designer and owner. Both have small children and believe that they should not be relegated to distant rooms filled with primary-coloured plastic toys.

Maria is the founder, with her husband Adam Hills, of Retrouvius, a showroom in west London, stuffed with the reclaimed relics of Britain's grand Victorian institutional and industrial past. The place is stacked with former school laboratory benches and panelled display cases from museums, while old lights in green enamel or frilly glass hang in constellations from the ceiling. These - along with piles of vintage textiles - are among the primary resources for Maria and her team of fellow architects on the design side of the business.

These are not the obvious elements for furnishing a Georgian interior - but the owner was an early convert to the reclaimed look. Long before she met Maria she had a pair of bashed-up old armchairs with leather that had dried to a worn suede-like patina. 'I like things that have a story,' she says.

These days, when you walk through the bright orange front door, the same leather armchairs are in the hall, looking perfectly in place against the child-friendly Ovaltine-hued walls and red Moroccan rug. On the right is an original Georgian window, which Maria has retained, and which provides a glimpse into one end of the new sitting room. 'I love an internal window,' explains Maria. 'They give a nice feeling to a house.'

Turn right from the hall and you are in the 34-foot-long sitting room. Though the space is imposing, Maria has been careful to keep the room relaxed and casual. 'It's a place where you can stretch out on a sofa and read the paper,' she says. At one end, Maria installed a late-nineteenth-century, Royal Doulton glazed-ceramic chimneypiece in peacock blue, with the same blue picked up in the paint on the chimney breast, in the corduroy loose covers on the Arflex 'Cousy' sofas and on the trim of the curtains, which run the length of one wall.

Maria has partitioned off one end of the space to create a television room for the children, using reclaimed mahogany doors, glazed with square Edwardian 'copper light' panes. The doors slide into pockets in the wall to unite the two areas. At this end of the room, another peacock-blue chimneypiece echoes its counterpart opposite, but this time it is covered with Moroccan-made Zellige tiles by Agnes Emery, the Belgian designer behind Emery & Cie, whose tiles and paints are displayed at Retrouvius. A cast-concrete shelf across the chimney breast, an enormous day bed and bright red, mid-century chairs provide the seating for the family's 'Film Fridays'.

Turn left from the hall and you are in the kitchen - where a tall cast-iron shelf unit from the Patent Office shields the main kitchen area. The units were made out of wood from the Natural History Museum, set at an angle and overlapping, to form both drawer front and handle. A large table in the dining area, made from iroko hardwood laboratory benches, has a bench and leather backrest on two sides, so lots of little boys can cram in to have tea, and a row of twinkly cut-glass hanging lights above give a jolt of glamour to the table for dinner parties. 'I love the way Maria has used lighting to define the spaces, and to create different moods in the house,' says the owner. Just off the kitchen, a study/dining room echoes the dark tones of the hall, with bookshelves lined in a nineteenth-century, French striped wallpaper, of which Maria managed to find just enough for the task.