Question Time presenter David Dimbleby embarks on a voyage of discovery of Britain's buildings in his latest TV incarnation - and finds a disturbing insight into his own past, as Ellie Genower finds out.

HE may be more used to refereeing heated debates on Question Time or anchoring events like the election coverage, but this week we see journalist and presenter David Dimbleby taking a breather from heavyweight political issues and embarking on something completely different.

In the new BBC1 series, How We Built Britain, he takes a tour around the country to tell the human story behind the country's majestic buildings and humble abodes.

It was lovely to do it,'' David says. I've always enjoyed buildings. I'm no expert, but it seemed too good a chance to miss.

It was a great journey of discovery for me, because I learned lots of things about buildings I'd never been to before, which was lovely. It was a mixture of a sort of holiday tour of Britain and discovering more about the buildings you're looking at.'' Clearly, David is enthusiastic and proud of the series, which took him from the pomp and splendour of Blenheim Palace in Oxfordshire to working class tenement houses in Glasgow.

The idea behind the series is exactly what it says,'' David smiles.

Why does the country have the buildings it does, and what do they tell us about the social and political history of Britain and the power structure? It's looking at buildings in a different way - not just technically. What we're saying is, Why did this building get to be built here and why does it look like this?''' This week, David travels to East Anglia to examine buildings erected as a result of the Norman conquest of Britain, filming at majestic Ely Cathedral and Lavenham in Suffolk.

The Normans redistributed the land and established their own power,'' David says. They built castles, which hadn't been built in stone before, and great cathedrals, which were mainly religious buildings but had a secondary purpose which is that they established power again.'' For the first time in 40 years, David also visited Dembleby in Lincolnshire, home to his ancestors.

I went there once to see if I could find my roots, but I couldn't find anything,'' he says. And then when I went this time, this bloke found out that one of my ancestors was some murderer!'' From one violent history to another, David then examined the Tudor era, when King Henry VIII destroyed the monasteries.

When the monasteries were destroyed, England's prosperity increased,'' David explains.

Favoured courtiers of Henry VIII would be given land or be able to buy land at a knockdown price. So you got a great surge of building.'' And then came the Elizabethan golden age.

Elizabeth relied on her courtiers to do the hard graft and ruin themselves building,'' David laughs.

They wanted to entice her into a royal visit, but it bankrupted them because she used to turn up with 200 people and they'd have to entertain her for a week with fireworks, balls and various excitements.'' After travelling to Scotland, looking at the castles and black houses of the Outer Hebrides, David moves on to the grand Georgian villas of Bath, and then the Victorian buildings of the industrial North West.

That's about the surge of enterprise under the Victorians,'' he says. The flood of people into Manchester was such that they lived in this appalling squalor, and clearly something had to be done about it. So the Victorians set about building a sewage system, which we visited.'' The Victorian era also saw the development of the railways and the expansion of London into sprawling suburbia.

The big story of the suburbs was the Metropolitan railway line,'' David says. It went right out towards Aylesbury. They sold the land off to developers all the way along, and then hit people with advertising.

The idea was that you get fresh air out in the countryside, and London was bursting at the seams and was pretty horrible to live in.

You could have a perfect balance, working in the city and returning home every evening on the train to your family in the leafy suburbs.'' Home for David is Polgate in East Sussex where he spends his spare time walking, sailing and going on journeys''. So travelling and filming around Britain must have suited him down to the ground.

I hope this series will excite people and give them a different way of looking at buildings," he says. "Not just looking at them because they're beautiful, but as a story about Britain and how it came to be as it is.

* David Dimbleby's How We Built Britain, begins on BBC1 on Sunday at 9pm