A map of the Netherlands has been drawn up to show the areas where houses are at risk of foundations problems, according to housing minister Mona Keijzer.

The “pand zakking kaart” gives an indication of the location of 425,000 buildings which need imminent repair because they are sinking into the ground.

Urging people “not to panic” in the face of a huge national problem, Keijzer told a parliamentary committee on Thursday that homeowners were responsible for their own buildings.

A year ago, the RLI environment and infrastructure agency said 425,000 buildings urgently need repairs costing some €50 billion, due to problems with rotting wooden piles, vulnerable peatland, and river and clay areas that have dried out. One in eight homes may eventually face costs.

Climate change is one cause, as well as inadequate foundations and, according to the RLI, 20 years of homeowners, mortgage lenders, government and insurers “looking away”. It said an average repair could cost €120,000.

Twelve months later, Keijzer has announced that the government expects two reports before the summer: a Deltares/TNO map of the precise location of at-risk property and advice from ABDTOPConsult, a government quango.

A €56 million fund is being established to offer loans – with three years interest and repayment-free – to those with no other financing options, some municipalities have set up expertise points and a national helpline is coming.

But she stressed that the burden of repairs will have to be borne by homeowners. Property sale prices have almost doubled in the last 10 years, and she said that people would, if necessary, always have the option of selling.

“At the beginning of the year, a building subsidence map was delivered, showing in which areas of the Netherlands buildings have a foundations risk,” she said. “These maps will all become searchable, at first for professionals and then more widely. But there is a risk in this.

“It doesn’t mean that if you have a house in an at-risk area, that it applies to your home. It can be different for each street. So it is important for us to navigate this carefully and see the maps for what they are: large-scale maps of the Netherlands and areas where there is a risk. That’s different from saying it applies to your house.”

Social unrest

The foundations crisis will impact a chain of financiers and investors in Dutch property, according to Merlien Welzijn, MP for New Social Contract. “A lot of people are watching this,” she added. “This is a subject that has social ramifications and I know that a lot of house buyers are looking. We have local expertise points, a fund, we have financing, we have the government, and the individual buyer needs to know where they can go for which questions – and where they can’t.”

Some MPs asked whether psychiatric support would be available for homeowners who couldn’t sleep at night for the worry of facing a bill of tens of thousands of euros. “There will be people who fall out of the boat,” said Geert Gabriëls, MP for GroenLinks-PvdA. “We should not be too matter-of-fact about all this. A lot of people are not aware of this and you should make it clear. Let’s have more attention.”

But Peter de Groot, MP for the VVD, warned that while it was time to take action, he was concerned about mass panic if people realised the extent of the Netherlands’ foundations problem. “We need to keep the calm because this could cause social unrest,” he said.

Plan to come

A broadly-supported motion from D66 MP Jan Paternotte last year suggested more obligations for house sellers, while banks and the AFM financial authority have proposed climate labels on foundations and flooding risks.

The Economist, studying the impact of climate change on global property values, recently said a “back of the envelope calculation” suggests Amsterdam house prices could drop by 40%. Some foreign financiers are refusing to fund Dutch building projects without flood risk assessments, according to Ballast Nedam.

Sandra Phlippen, chief economist at ABN Amro, told The Sunday Times last year that she feared that, without political attention, poorer and riskier parts of the Netherlands could literally become sink estates.

The housing minister will be consulting estate agents, valuation experts, banks and financial experts on sharing information, since anyone selling a property has a legal obligation to inform the buyer about the building. A government plan on foundations is expected this year.