A string of court rulings about rent agreements in the private sector could mean large institutional investors will have to pay back up to €6.4 billion in excess rent to tenants, the Financieele Dagblad said on Monday.

The figure comes from research carried out by landlords into the possible impact of several cases that found tenants had been overcharged for years. The Supreme Court is currently looking into the situation. 

If landlords are forced to refund money to tenants, it could put some of them in liquidity problems, Wim Wensing, chairman of institutional investors organisation IVBN told the paper. 

“It will have an impact on property values… and consequences for our capacity to invest in new housing and make our current portfolios more energy efficient,” he said. “It will have a wide impact on society.”

Big commercial landlords used to put up rents by inflation plus between 3% and 5% a year. How much extra was up to them. However, several lower courts have said this is unfair and conflicts with European consumer protection rules. 

They have, therefore, in some cases scrubbed all previous rent increases, leading to cuts of hundreds of euros a month for tenants.

If the Supreme Court accepts the lower court position, it will affect the rents of all 600,000 privately owned free sector homes plus 100,000 more expensive properties owned by housing corporations, the IVBN says.

Since 2021, the government has restricted the maximum rent increase in the non-rent controlled sector to inflation plus 1% or the average pay rise plus 1%, whichever is lower. 

MPs recently voted to continue this process up to 2027.