Copyrighted imageCredit: BBC Evan inspects the new roof of St Pancras station Britain's infrastructure - the roads, railways, water and power networks we all rely on everyday - is creaking. In this two part series from the BBC and The Open University, Evan Davis sets out to find the scale of the engineering challenge Britain faces, and how we can tackle it. Once we were famous around the world for our epic feats of civil engineering - now we need to rediscover that spirit.

In Episode 1, Evan takes you deep under London to meet Phyllis. She’s one of the vast tunnel boring machines burrowing their way under the capital’s teeming streets, carving the tunnels for Crossrail, the new railway which will run across the capital. It’s proof that we can pull off big engineering projects in this country, and also evidence of why infrastructure matters to the British economy.

London's population is growing fast - and our engineering needs to keep up. As Evan travels across the country talking to Britain’s best engineers and architects, that idea of infrastructure keeping up with the ways we're changing as a nation will emerge as a key theme.

Evan will also show the scale of the challenge we face in future-proofing Britain – he'll find out how the bill for the work we need to do will come to hundreds of billions of pounds (and how we'll all be footing it). He'll discover how hard it is to decide what to build today for the Britain of tomorrow, and how tricky it is to balance the infrastructure we need with the back gardens and green spaces which we love.

Yet over all, Evan will show how the challenges can be overcome - and how we've rediscovered our great tradition of epic engineering.

Throughout, the film provides stunning access to bits of Britain you hardly ever see. It will take you from the breathtaking views at top of the Forth Road Bridge, to the teeming runways of Heathrow airport, to the valve towers of Britain's biggest man made reservoir. Yet this is a series about much more than engineering – it's about us all, and our ambition as a nation.

Evan will show why better infrastructure is vital to the British economy, and why the choices we make today will shape our future.

In Episode 2, Evan reflects on some of Britain’s less successful infrastructure projects of the not-too-distant past and looks at how we’ve learnt from our mistakes to become a nation which is once again rediscovering its skill for epic engineering.

For many years, Britain has patched and mended the existing infrastructure but recent successful projects such as the Olympics and High Speed One show that Britain is now better equipped than ever to deal with the challenges we face.

As he explores some of Britain’s recent success stories, Evan asks what helps to deliver a successful engineering project. He rides in the cab of a Javelin train speeding through the Kent countryside and explores the underground power tunnels built to house the high voltage lines which powered the Olympic Park. He also visits two sites where new technology is being trialled, with the aim of increasing the capacity of Britain’s existing rail and motorway networks.

• More on episode one
• More on episode two

Built In Britain comes to BBC Two from Sunday 7th October 2012. For further broadcast details, and to watch online where available, please visit bbc.co.uk