Britain's Most Expensive Houses

Broker Josh digs deep into his network to close a deal on an £80 million penthouse in Knightsbridge, while agent Tim brings Lynford Hall, a 20-acre country estate built in 1856 in Norfolk, to market.

Mark goes all-out for a glowing review of a £3.5m Scottish castle, but can he attract buyers? And will Ian's bold moves pay off on an 11-acre, five-bed cottage with coastal views?

In Knightsbridge, Raj juggles selling an £18m townhouse with a £27k per week rental. In Stratford-upon-Avon, Jonathan takes a home with a private jetty onto the Avon river to market.

Agent David hopes to capture London's elite with two lavishly luxury chalets in Val d'Isère. And Fine & Country agent Margaret's £10m Hertfordshire mansion catches Hollywood's eye.

Adrian takes a unique rent-before-you-buy approach on a £14.95m coastal retreat. And can Constance land her biggest deal yet: a £60m home with unrivalled views of Hyde Park?

Margaret showcases a £17m manor in Jersey, complete with Versace-style reception rooms, a wine cellar and a labyrinth garden. And there's a tense valuation for Ian on a 16th-century house in Cornwall.