St Albans is the most expensive place to move from a two-bed flat to a three-bed house outside London, with buyers paying an extra £185,640 on average.

Strutt & Parker believe that such premiums are down to a combination of growing families trading up and baby boomers downsizing – with both groups wanting a three bed home.

This increased demand combined with a shortage of supply has resulted in sky high prices in south eastern cities, with Winchester (£160,108) and Chichester (£142,157) experiencing the next most expensive moving costs after St Albans, followed by Brighton & Hove and Ely.

Stephanie McMahon, Head of Research at Strutt & Parker, said: “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.

“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.”

The figures exclude London and are based on the average prices recorded by Rightmove between July 2015 and June 2016, which were then analysed by Strutt & Parker.

The most active purchasers were found to be young parents with growing families, many of whom look to cathedral cities for the perfect mix of commutability, lifestyle and schooling.

Rozanne Edwards, Head of Strutt & Parker St Albans said: “For young professionals looking to upsize within St Albans, they face stiff competition from London buyers seeing St Albans as a commuter hotspot thanks to our 19-minute journey time and pretty medieval centre.

“This makes the three-bedroom home here in huge demand, often attracting competitive bids and selling within days of launch.”

She added: “This mix of locals and Londoners, from couples to young families, is a pressure point for our market. Demand in St Albans is far out-stripping supply at the moment, so with this trend likely to sustain, it is unsurprising that we rank highly on the list for price premiums.”