It’s hard to believe that Location, Location, Location, the property-search programme that launched so many others, including the spin-off Love It or List It, is in its 21st year.

Over 36 series Kirstie (Allsopp) and Phil (Spencer) have helped more than 400 families make life-changing property decisions and allowed us to peer into homes from Arbroath to Abersoch. They’ve travelled 100,000 miles, been entrusted with £141,350,500 of house hunters’ money and become national treasures in the process.

When we meet in Kirstie’s west London kitchen, she is still talking over Phil and Phil is still, with immense good humour, trying to put her right.

“Too much detail!” he hisses at intervals, drumming his fingers on a vast mahogany table, as she ploughs through