Parliament’s Environment, Climate and Biodiversity Committee approved two linked reports on 13 July, clearing the way for votes on renewed financial support and a permanent inspection regime for heat pumps.

One bill would reinstate the Klimabonus Wunnen scheme from 1 January 2026, after its previous legal basis expired at the end of last year. The other would require heat pumps to be checked after installation and inspected regularly throughout their working life.

Environment minister Serge Wilmes told MPs that officials had continued examining applications during the six-month gap but had been unable to approve or pay grants. “We can examine the applications, but we cannot approve the grants or pay them,” he said.

A temporary €2,000 top-up

The renewed support scheme would apply retroactively from the start of 2026. Temporary increases agreed during the June tripartite talks would run until 30 June 2027, while the wider programme would remain in place until the end of 2030.

A further €2,000 would be added to grants for geothermal and air-to-water heat pumps installed in existing homes. The equipment would have to be ordered by 30 June 2027 and the final invoice issued by the end of 2028.

Support for energy advice would also rise temporarily, while grants for some renovation work would increase by between 15% and 20%. The measures come as the International Energy Agency has warned that Luxembourg’s buildings sector is lagging in emissions cuts, with almost 85% of homes still reliant on fossil fuels for heating.

Lower upfront costs

Jeff Boonen (CSV), rapporteur for the housing-support bill, highlighted the introduction of pre-financing. From 1 January 2027, participating contractors would be able to deduct the expected grant directly from the customer’s bill and recover the money from the government, while the existing reimbursement route would remain available.

The measure is intended to reduce the amount households must pay before receiving public support. The IEA identified the overall cost gap between heat pumps and fossil-fuel boilers, including installation and running costs, as the main obstacle to faster uptake.

One in three non-compliant

The second bill would replace temporary controls introduced in August 2025 with a permanent legal framework.

Anne Majerus, deputy director of Luxembourg’s Environment Agency, told MPs during the committee’s substantive discussion on 1 July that one third of the heat pumps checked under the temporary rules had not met the requirements. “Of all the heat pumps inspected since the temporary regulation entered into force last summer, one third were not compliant,” she said. “That is still a relatively large number.”

The problems included systems that were too large for the property, installed in the wrong place or configured incorrectly. Wilmes said households could buy a heat pump in good faith, receive a subsidy and then find that it did not perform as promised. “In that case, we risk losing some of our citizens on the road to the ecological transition,” he said. The government argued that poor installations could undermine confidence in a technology that households were being encouraged to adopt with public money.

After the first winter

The company commissioning a new heat pump would have to request an installation check within one month. Luxembourg’s skilled-trades chamber would carry it out, with the current cost to the household set at €179 including VAT.

New systems would receive their first periodic inspection between one and two years after commissioning, while existing systems would have to undergo their first inspection within two years of the law taking effect.

“We want the heat pump to have gone through one winter so that we can see whether everything is really working as it should,” Majerus said.

Most systems would then be inspected every four years. The interval would rise to five years for equipment that can be monitored and controlled remotely, while heat pumps with an output above 290 kilowatts would be checked every three years.

Safeguard or brake

Franz Fayot (LSAP) questioned whether the controls could slow the spread of a technology Luxembourg wanted households to adopt more quickly. “Are we not putting obstacles in our own way by adding an administrative burden in an area where we want to move faster?” he asked.

Wilmes acknowledged the concern but argued that poor workmanship presented the greater risk. “We have a duty to make sure that, when this technology is installed, it works properly and according to professional standards,” he said.

The bill would reserve installation, modification and maintenance work to authorised heating, plumbing and refrigeration businesses. Inspectors would need specialist training and certification, while the Environment Agency would keep a register of approved and inspected systems.