Ifeu study shows urgent need to renovate old buildings

28.03.2025

Source: E & M powernews

The Ifeu Institute analyzed the heating energy requirements of buildings. As unrenovated buildings require up to ten times more heating energy, they need to be specifically renovated to protect the climate.

Environmental Action Germany (DUH) has called for greater political support for energy efficiency in the building sector. This is based on a recent report by the Institute for Energy and Environmental Research (Ifeu), which was commissioned by DUH and produced with the support of the German Sustainable Building Council (DGNB). According to the report, unrenovated buildings in the worst efficiency classes consume up to ten times more energy than modern buildings, but are largely ignored politically.

The Deputy Head of Energy and Climate Protection at DUH, Paula Brandmeyer, emphasized that a comprehensive refurbishment of the so-called "worst-performing buildings" is necessary: "Only if buildings become more efficient will heating costs remain affordable and the climate targets achievable". DUH criticizes the fact that the issue is not being given sufficient consideration in the current political negotiations. People on low and middle incomes are particularly affected by high energy costs. "Energy efficiency is the basis of a socially just heating transition," she said.

Renewable energy is not enough without renovation

The Ifeu report emphasizes that energy-efficient modernization reduces energy costs in the long term, improves quality of life and relieves the burden on electricity and heating networks. The co-author of the study, Peter Mellwig, said: "We have to take care of the old buildings!" Only with a renovation offensive could the energy demand be reduced so that it can be covered by renewable sources. To achieve this, subsidies must be changed so that landlords have an interest in heat renovations, even though tenants will have lower operating costs as a result.

DUH is calling for concrete measures to promote refurbishment, including a reform of the funding landscape, the adjustment of legal requirements and binding political targets. The report highlights the central role of energy efficiency for a socially just heating transition. Without a consistent refurbishment of the most inefficient buildings, households and the energy system are threatened with a long-term burden.

The Ifeu report presents targeted measures to increase the renovation rate and effectively modernize the worst-performing buildings.
This includes adapting regulatory law and setting clear political
targets. Brandmeyer criticized the fact that neighboring European countries have long since tightened efficiency requirements, but Germany has not. "We need a clear change of course in building policy," she demanded.

The Ifeu report on building refurbishment is available to download as a PDF on the DUH website.

Author: Susanne Harmsen