How much does a complete energy-efficient refurbishment really cost? And is it financially worthwhile? A new analysis of real cost data by the non-profit consultancy co2online shows that anyone upgrading a detached house for energy efficiency must expect to invest 108,000 euros in a complete refurbishment. Thanks to funding and savings in heating costs, the financial burden over 20 years is only 154 euros per month. In many cases, refurbishment can save owners money in the long term.
Modernisation instead of maintenance
More than half of the refurbishment costs are maintenance costs that would become due sooner or later in any event, for example for a new façade or the replacement of old windows. Those who use this work to bring their home up to the latest energy standards at the same time benefit from permanently lower heating costs, a better indoor climate and a higher property value.
Renewable heating systems such as heat pumps, pellet heating or a connection to district heating are also affordable thanks to high funding rates. An air-source heat pump costs an average of 17,000 euros, and up to 70 per cent of the costs may be funded. By contrast, in view of rising CO₂ prices and high operating costs, a condensing gas boiler is no longer a cost-effective alternative. The figures show that switching to renewable energy pays off in the long term.
Calculate individual costs
Every house is different, as are its individual costs and potential savings. co2online’s free ModernisierungsCheck helps homeowners make an informed decision. Based on a few details about the building, the tool provides a realistic estimate of investment costs and potential savings. co2online uses its own calculations and independent benchmarks based on invoiced construction prices from the German Chambers of Architects’ Construction Cost Information Centre for the fourth quarter of 2024. The free tool either identifies the property’s potential or evaluates planned measures.