Grand Designs: Trade Secrets Episode Rating Graph

The inside track on castles: Kevin and the team have tracked down a challenging selection of wrecks and ruins available to buy and Naomi and Deborah offer hints and tips on how to transform a dark drafty castle into an über-cool home.

Kevin is joined by Naomi Cleaver with her tips on creating a luxury country interior and roving reporter Tom Dyckhoff will be in Holland, searching out the most cutting edge thatch.

Naomi Cleaver has everything you need to know about creating cool chic from other people's rubbish, while Tom Dyckhoff discovers a beautiful building built from discarded car tyres.

Kevin McCloud and Naomi Cleaver look at the do's and don't's of penthouses, crucial advice for any would-be grand designer and Tom Dyckhoff looks at ways we could all be building on other people's rooftops.

How to create an eco house that doesn't look as though you've knitted it yourself while Naomi Cleaver dispenses interior design tips on how to make our homes happier and healthier.

Tom Dyckhoff investigates how to convert a church in to a home, and Naomi Cleaver has everything you need to know about salvage, what to use and where.

Kevin McCloud and the team discuss an Art Deco house in Surrey, while Naomi Cleaver shows us the second-hand options for creating a stunning Art Deco interior.

Kevin McCloud and Deborah Saunt discuss the Grand Designs house built on a tiny plot in Peckham. Tom Dyckhoff reveals the secrets of finding an awkward plot and shows some examples.

Tom Dyckhoff looks at how to buy a timber frame second-hand, while Naomi Cleaver reveals all you need to know about using wallpaper, and its revival from the ridiculous to the revolutionary.

Tom Dyckhoff looks at how to build with straw bales and Naomi Cleaver reveals some clever ways to use glass in our homes.

Tom Dyckhoff looks at what you can and can't do with an old building in Italy, and Naomi reveals the best way to cut through Italian red tape.

Kevin McCloud is joined on the show by Naomi Cleaver and architect Deborah Saunt to discuss a house in South London made almost entirely from timber.