Very few home owners will be able to make their property energy neutral without facing an increase in monthly costs, even though the process is supposed to be cost-neutral, the Dutch Environmental Assessment Agency said on Monday.

All homes in the Netherlands should to be energy-neutral in 2050, in line with government targets. And that means 200,000 a year will have to be converted.

However, the PBL says, home owners will have to invest far more in insulation and alternative energy sources than they can earn back, and this will make them more reluctant to make the switch.

The owners of a house with a D energy label will have to invest some €35,000 on making it energy-neutral – which will cut €50 a month from utility bills. The agency says this means it will take decades for most households to earn back the cost of the investment.

The current subsidies available to home owners are not enough to make such investments attractive in the long term, the PBL said.

‘This means many households will wait for the cheapest, and possibly most sensible, option,’ the agency said. ‘But it remains to be seen if innovation and standardisation will make boosting sustainability more attractive financially in the future. The costs will have to go down a lot.’

According to research group New Energy Research, one million homes in the Netherlands are now fitted with solar panels, some 30 years after they were first introduced.