A man's house may well be his castle, but not every man would build a turret on his roof to emphasise the point. Or, indeed, put almost as much stained glass in his front window as you'd find in the average cathedral, and encase a billiard room in Jacobean-style plaster and panelling. However, the man who built Fayre Haven, a spectacular 10-bedroomed Edwardian folly in Preston, did all that and more. That man was JR Hodgson.

The aim of The House Detectives, a new historical and architectural series on BBC2, is to uncover characters like Hodgson, as well as telling the tales behind the walls of the houses of everyday folk. It is a sort of thinking person's Through the Keyhole, with educational flesh on voyeuristic bones, and, you may be relieved to know, hosted by Juliet Morris instead of Loyd Grossman. In short, the programme asks of the dwellings it examines, who lived in a house like this? And where did they get those curtains?

The series grew out of a 10-minute slot on One Foot in the Past about three years ago, followed by a pilot programme which investigated a dwelling in West Norwood, London. After an appeal for more houses, the BBC received 250 letters from viewers willing to put their homes under the historical microscope. Six were chosen from a shortlist of 40. "Nobody on television has looked into ordinary people's houses before," claims series producer, Sally Angel. "The secret history of their homes has remained untold. The house is a silent witness and if you can read it, you can unlock the past lives that people have led."

The trio of house detectives are well qualified to decipher the code of residential Britain. Judith Miller (creator of the Miller's Antiques Guide) is an interior design historian, Mac Dowdy is an architectural historian at Cambridge University, and David Austin is a landscape archaeologist. "I'm a socialist and this is bottom-up history," says Austin, Professor of Archaeology at the University of Wales, Lampeter. "During the Thatcher years, it was decided at Cabinet level to study history from the top down, to focus on great people and places. But this programme is about communities and people - it forms an important part of legitimate history."

The House Detectives visits properties around the country, all of which have a tale to tell and require some unlikely skills. In Manningtree, Essex, a house rumoured to conceal smugglers' tunnels was scrutinised by specialists with pulse radar equipment - the same experts who looked into Fred and Rosemary West's back garden in Cromwell Street, Gloucester. Dendrochronologists were recruited to determine the age of wooden beams in Herefordshire, while an archivist from Pilkington Glass trawled old catalogues for antique samples.

Before shooting, extensive research is carried out, with the BBC plundering someone else's archives for a change. Local record offices and libraries are the next port of call, with maps, newspaper cuttings and census forms providing vital clues about the architectural whimsy of former occupants.

But this new-found knowledge about their beloved four walls can be hard won for the families concerned. In Preston, for example, the eight-strong BBC crew spent a week with Phil Hulme, his partner, Anne, and their baby, Harriette, sharing their house for 11 hours a day. In the course of filming, the family discovered that their own curiosity with Fayre Haven was shared by their neighbours. "I've walked past the house for the last 26 years, about once a day and I've always wondered about it," one remarks.

The story which emerges of JR Hodgson is of a self-made man, a successful plumbers and painters' merchant who became Mayor of Preston. His aspirational nature shows itself in the ostentatious design of his former home. The coloured glass and wall coverings were available in JR's early version of B&Q in Preston town centre.

Over the next six weeks, the programme covers extraordinary houses owned by ordinary people and aims to show that, in the words of Juliet Morris, "History isn't just on your doorstep - it is your doorstep."

`The House Detectives', Tue 8pm BBC2