The rent charged for four in five rooms offered via website Kamernet is too high and breaks official rental rates, according to research by radio current affairs show Argos.

The programme’s researchers checked 1,200 rooms in shared housing offered for rent via the site and found on average landlords were charging €146 a month too much.

Many people are not aware that the rent for rooms in shared houses is determined by a point-based system, which sets a maximum rent depending on facilities and the size of the room.

‘The problems are worst in the biggest cities,’ Argos researcher Reinier Tromp said. ‘In Amsterdam and Utrecht, hardly anywhere is priced in line with the points system and 95% of the rooms in both cities are too expensive. In The Hague, the figure is 88%, in Rotterdam 86% and in Groningen 86%.’

Amsterdam landlords are asking an average of €307 more for a room than is legally allowed, Argos said. It calculated that the average price of a room, according to the rules, would be around €360 a month.

For example, currently on Kamernet is a 12 square metre room on the Pieter Calandlaan in the west of Amsterdam for €800 a month, but even €500 for a large room in a shared house is too expensive, according to the points system.

Tenants who feel they are paying too much can go to a rent tribunal, but many are reluctant to do so because they are worried about losing their home, Argos said.

Kamernet told Argos in a reaction that it is simply a ‘market place’ and not responsible for setting rents.

Private landlords association Vastgoedbelang said the results of the survey show that the point system needs revising and modernising.