Sarah chats to Greg and Kevin about her Durham Dales hemp house and project management pitfalls. She shares the joys of building her house from hempcrete and discusses what living in the house has been like.

The build is in Southwater with Pete and Aey, who order a super-sustainable modular home. Kevin and Greg get stuck into modular building and sustainable timber, and catch up with Pete and Aey direct from their new cutting-edge home.

Marcus and Abi have just £100k to build a luxurious off-grid family home deep in Pembrokeshire. Granted permission through the One Planet Development planning laws, they're armed with determination and timber from the surrounding forest.

In the Surrey Hills, Pep and Malene construct a modern take on a Viking Hall. Following Pep's cancer diagnosis, it's a real race against time to create a house that can represent their shared life together and a house of memories in years to come.

Kevin McCloud and Greg James dish the dirt on the latest episode of `Grand Designs'. Piers and Emma chat about the towering complexities and costs of their 21st-century castle.