Over one in five homes which found a new owner last year was sold at a loss, according to an investigation by broadcaster Nos.

Nos bases its claims on information contained in the land registry, or kadaster.

In total, 17,913 flats and houses changed hands at a loss, an increase of 40% on 2012. Taking buyer costs into account – which are often financed by the mortgage – the land registry said up to one-third of homes could have been sold for less than the total purchase price.

Homes kept their value best in Noord-Holland and Zeeland, the Nos research shows. Flevoland, the new polder east of Amsterdam, showed the worst price erosion.

One Flevoland estate agent told the broadcaster: ‘In terms of prices we are back at 2001 levels. Houses bought for €235,000 or €240,000 in 2008 are now selling for less than €200,000.”

In 20% of the loss-making properties, the price difference was at least €40,000.