Home is where the past is

One of the most important sources is the county record office, where documents, such as historical maps, give an easy indication of the age of the house. Then it's on to the process of going back through the tithe awards for the parish and the censuses.

Marr says: "Surprisingly, it's the very abundance of records that causes problems," says Marr. "It is impossible to find a point at which I can sit back and say 'I've finished this house history'.

"At the end of any search, be it the county record office or another archive, I submit a report on what I've learned so the client is kept fully informed at all times. Sometimes they may want to put a cap on the total cost of the research, say £3,500." A house historian costs around £315 an hour.

The Allens live with their two children in a three-storey, early 19th century house in Camberwell, convenient for the City, where Peter works. The building has many of the original architectural features including a magnificent sweeping central staircase. Since moving there last September, the Allens have been keen to find out more about its history; it is part of a close in which a dozen gracious homes appear to have been built around the same time. The properties were built as semi-detached pairs, all have impressive porticos at the front and wrought-iron balconies at the back. "The houses around here are quite distinctive," says Sally, "and the neighbours are very interested in their history."

House historian Dr Nick Barratt and colleague Dr Carol Davidson-Cragoe, an architectural historian, agreed to undertake some preliminary research on the house to show what a simple, initial search could reveal.

Barratt first headed to the Public Record Office. It contains a wealth of information concerning the state and individuals: maps and plans, details of land transfers and electoral registers. Barratt discovered the Parish of St Giles tithe map of 1845 on which the Allen's property is clearly marked. This was confirmed by reproductions of contemporary maps owned by the Allens' neighbours. These earlier maps also indicate that, at that time, much of the land in Camberwell was used by market gardeners who provided London with fresh produce.

The PRO also holds the census of 1901. This information is still not online, but anyone can carry out research at the archives. The census shows that the house was lived in by Francis Plumpton, a businessman who traded in aerated water.

To go back before 1901, Barratt went to the Family Records Centre, which archives details of births, marriages and deaths, and holds the censuses from 1841-1891. These show once again that the house was inhabited by prosperous lower-middle class families employing servants, evidence of the area's growing status as a gentrified suburb of London. The census of 1851 shows that it was lived in by a "fundholder", Thomas Allfort, with his niece and their two servants.

What is striking is that the profile of the family living in the house hasn't altered much in 150 years, despite the fact that, postwar, Camberwell was a relatively depressed area. Now, highly desirable Victorian family houses are being snapped up across the city, and the Allen family is similar to the original occupants: Peter Allen is a Lloyd's broker, and the household includes the Allens' children, three-year-old Holly and one-year-old Sam, as well as a live-in nanny.

"I would also go through the maps at the Southwark Local Studies Library and the London Metropolitan archives," says Barratt. "Private papers of the original landowners should also contain invaluable information on the development of the close and the surrounding area, and may even include correspondence with builders and architects."

Architecturally, Davidson-Cragoe says the style of the property is consistent with late 1830s design. "Looking along the street you can see that it was one of four pairs of houses built by the same person, as the portico details are almost identical," she says. "It is useful to compare your house with the neighbours' to see what has changed. Doors, windows and woodwork are all good clues to the date of the building."

One of the archives Davidson-Cragoe referred to was the National Monuments Record, which has information on the buildings and social life of London. "The next step would be to visit the Southwark Local Studies Library and the Guildhall Library," she says.

So how does Sally feel about the new information? "It's very interesting, and quite clearly there is an enormous amount of history attached to the area," she says. But at the moment Sally hasn't decided whether to delve further into the history of the building. "I do wonder who has lived here before, but I also have niggling worries that I might unearth some dastardly deeds, or a period of unhappiness here. This is the first house we've had as a family and for us, this is a happy, family house and that's how I want it to stay."