St Albans has been ranked as the most expensive location for a family to upsize from a two-bed flat to a three-bed house, new analysis by Strutt & Parker has revealed. Buyers here would be paying an extra £185,640 on average.

The reasons for such premiums are two-fold, according to agents: the number of growing families looking to upsize and the number of baby boomers looking to downsize, with both demographics seeking a three-bed home in an amenity-rich city location.

Thanks to increased demand and inadequate supply, cities in the south east of England rank highest when it comes to the costs of trading up. Behind St Albans, the ancient cities of Winchester and Chichester took second and third place for price premiums respectively.

Liverpool, by contrast, was revealed to be the most affordable city for upsizers, with the possibility of buying a larger property for no added expense.

Stephanie McMahon, Head of Research at Strutt & Parker, commented on the findings: “The largest price gaps are where competition for three-bed houses is at its highest. These family homes are a property ‘sweet spot’, attracting interest from buyers even at times when the rest of the housing market is relatively static.”

She added: “The most expensive cities generally reflect markets that are popular with growing families. Four of the top five are in the commuter belt, so this trend is most acute for those who have relocated from London.”

According to Strutt & Parker’s research, the most active buyers are young parents with rapidly growing families. Commuter cities are especially popular among this demographic, with their mix of good schools, commutability and a slower pace of life.

“The country market is alive and well – we have the highest level of buyers registering with us since 2012, with key cities outside of London showing exceptional growth,” Guy Robinson, Head of Regional Residential Agency at Strutt & Parker, said.

“These in-demand cities correlate strongly with trading up data, including the likes of Canterbury, Cambridge and Salisbury. These historic Cathedral cities offer the ultimate suburban idyll – a lifestyle mainly families aspire to.”