Newsletter "UBA aktuell" - No.: 2/2025 | Umweltbundesamt

Heat pumps also work in existing buildings

Mr and Mrs Krüger heat efficiently and in a climate-friendly way with their heat pump. Source: co2online

An air heat pump for a small terraced house? Ground collectors for an apartment block? A heat pump to support the heating system in a homeowners' community? There are still many questions when it comes to heat pumps. There is a great deal of uncertainty, especially for existing buildings: Is it really possible? And is it worth it? Since May 2024, the steadily growing number of good examples on the UBA portal “So geht’s mit Wärmepumpen!“ (“This is how it works with heat pumps!”) has shown that it can be done and how it can be done.

Examples of listed buildings, terraced houses and optimisation

A listed half-timbered house built in 1932 in one of the coldest regions of Germany saves 2,000 Euros a year on heating costs after installing a heat pump – without any facade insulation. A small terraced house without a garden or cellar is fitted with an air-to-water heat pump on the roof: “The heat pump can't be heard from outside and is usually very quiet inside the house. We sleep just one metre away from the indoor unit, and only occasionally does a low-frequency noise occur, which is still to be optimised through fine-tuning by the manufacturer,” writes the owner of the building.

Sometimes the new heating system doesn't work as expected at first. The Mücke family realised that the system was inefficient and provided poor level of comfort in terms of hot water. However, a retrofit solved the problem; efficiency was significantly improved, resulting in heating cost savings of 30 to 40 percent.

Examples also for apartment blocks and non-residential buildings

On “This is how it works with heat pumps!” there are also projects in non-residential buildings and apartment blocks. As the required flow temperatures and heating loads were not easy to determine due to the age of the building (built in 1890) and of the heating system, a homeowners' community from Konstanz decided in favour of a heat pump, which is supported by the existing gas heating in a hybrid system.

In the projects in the portal, homeowners or those involved in planning, energy consulting or architecture report first-hand on their experiences. Many have also provided an email address as a contact option.

Be a role model and share your heat pump experience!

Do you have a heat pump yourself in Germany? Then you are already a role model. Share your experience with others and show your project in the heat pump portal (in German)! Do you know other households with heat pumps in Germany? Then please forward this e-mail! 

Support from the project team

ifeu, co2online and Ingenieurbüro Heckmann are supporting the UBA as part of a research project with the design, development, maintenance and external communication of the “So geht’s mit Wärmepumpen!” portal. The project team can be contacted by e-mail at: UBA-WP-Datenbank@co2online.de .

UBA CO₂ calculator – new look with improved user guidance

This year, the UBA CO₂ calculator has not only updated the calculation factors, but also implemented improvements in user guidance. In addition to a new landing page, there are now direct aids for completing the queries. The “My climate policy” tool, which illustrates the impact of political measures on personal carbon footprints, has also been newly implemented. read more (in German)

How much does the federal government spend on climate adaptation? – an approximation

Adaptation to the consequences of climate change affects many policy areas. But how much the German federal government spends on adaptation activities was previously unknown. A new methodology developed by the German Environment Agency makes it possible to estimate the expenditure. An initial evaluation of the 2022 federal budget plan shows that between 2.1 billion euros and 3.4 billion euros was set aside for adaptation in 255 budget items. read more (in German)

CO₂ emissions per kilowatt hour of electricity decreased in 2024

Calculations by the German Environment Agency (UBA) show that the specific greenhouse gas emission factors in the German electricity mix continued to fall in 2024. The main reasons for this are the increased share of renewable energies, the fall in electricity consumption as a result of economic stagnation and the fact that more electricity was imported than exported. read more (in German)

Intergovernmental Panel on Climate Change in China: the topics are set, the timeframe is not

At the end of February, the most important figures in international climate science and the member states of the IPCC (Intergovernmental Panel on Climate Change) met in China to discuss the seventh reporting cycle on the status of climate change, which began in 2023. UBA staff members were part of the German delegation. One particularly controversial point of discussion in China was the timeframe for the seventh assessment report. read more (in German)

German national railway cools with natural refrigerant

Flammable natural refrigerants for railway air conditioning were previously a taboo for the railways. A field test has now demonstrated the feasibility of such a concept. A passenger train with a propane air conditioning system travelled on a regular service for a year. The propane system is at least as energy efficient as the system with the conventional fluorinated refrigerant. read more (in German)

Use of hydropower

According to the German Renewable Energy Sources Act (EEG), the expansion of renewable energies – including the use of hydropower – is recognised as being fundamentally in the public interest. The German Environment Agency has produced a factsheet on the question of how far this fundamental public interest extends when weighing up different interests in planning and authorisation law for hydropower plants. read more (in German)

Discovery of a plasticiser in urine samples – Questions & Answers

At the beginning of 2024 and in February 2025, the German State Agency for Nature, Environment and Consumer Protection of North Rhine-Westphalia (LANUV) reported the discovery of mono-n-hexyl phthalate in urine samples from children. The substance was also detected in adult urine samples as part of the sixth German Environmental Health Study (GerES VI). Here, the German Environment Agency (UBA) provides answers to the most frequently asked questions. read more (in German)

Trends of trifluoroacetic acid in trees from 1985 to 2022

Trifluoroacetic acid is a persistent and highly mobile substance whose levels in deciduous and coniferous trees have risen sharply over the last 25 years. A current study examines this development using archived leaves and needles from the German Environmental Specimen Bank. read more (in German)

Data on tourist mobility requested at regional level

Although the significance of tourist transport in terms of climate protection is well known, this transport is not continuously recorded empirically at all levels in Germany. This applies in particular to the regional level, where data collection is inadequate and incomplete. A project of the German Environment Agency (UBA) is therefore attempting to close this gap. We need your help to do this. read more (in German)

#WareWunder – UBA launches campaign for sustainable consumption

The German Environment Agency (UBA) is launching a campaign called #WareWunder in June 2025 to integrate sustainable products more strongly into consumers' everyday lives. The campaign will focus on seven environmentally friendly products that offer additional benefits such as cost savings, convenience and health. Local authorities, companies and NGOs are being called upon to take part in the campaign. read more (in German)

Environmental innovation programme saves wood in cross laminated timber production

With the support of the Environmental Innovation Programme, the production of high-quality cross laminated timber at Holzwerke van Roje GmbH & Co. KG in Rhineland-Palatinate saves around 17 percent wood compared to state-of-the-art methods by recycling waste and residual wood from its own production. The technology could also be used by other wood processing companies. read more (in German)

Integrating climate protection aspects into complex eco-labelling

A new UBA study summarises how carbon footprints can be used to determine the greenhouse gas emissions of products, which measures lead to a reduction in greenhouse gas emissions and which climate protection projects can be used to offset these emissions. It will then look at how these aspects can be integrated into multi-criteria eco-labelling schemes. read more (in German)

Evaluation of the recycling rates of the Packaging Act

A recent study commissioned by the German Environment Agency has evaluated the recycling rates of the Packaging Act and drawn up proposals for their further development. A comparison with the recycling results for commercial packaging shows a comparable level for paper and metals, while household packaging achieves higher recycling rates for plastics. read more (in German)

New UBA information film: Heating with wood – what to consider

A crackling open fire – cosy, but often anything but environmentally friendly. Wood-burning stoves cause a lot of particulate matter and CO₂. If you still want to heat with a wood-burning stove, you should choose low-emission models, operate them correctly and maintain them regularly. The new UBA information film „Heizen mit Holz“ (“Heating with wood”) shows how the environmental impact of wood-burning stoves can be reduced. read more (in German)

Particulate matter from Easter fires

Easter bonfires are a traditional custom that is primarily intended to welcome spring and symbolise the banishment of winter. However, Easter bonfires also produce particulate matter that is harmful to health. read more (in German)

KBU recommends amendment of the Federal Soil Protection Act

The Soil Protection Commission (KBU) at the UBA recommends that the Federal Soil Protection Act (BBodSchG) be expanded with a view to protecting the soil. Only then can the challenges in the areas of climate change, water balance in the countryside, nutrient cycles and biodiversity be met. read more (in German)

Toolbook for transformation design as a valuable practical aid

The project "Transformation fitness for sustainability projects: Training environmental projects and other sustainability initiatives in transformation fitness, using a DIY toolbook and training courses in participatory project, organisational and democratic development for sustainable transformation design" has led to a toolbook that is based on a great deal of process experience. read more (in German)

New study published on the development of environmental organisations

In times of polycrisis, transgression of planetary boundaries and social polarisation, the demands on environmental organisations are great. The new study by the Independent Institute for Environmental Issues (UfU e.V.) sheds light on the structural development and handling of the challenges faced by environmental organisations in Germany since the year 2000. read more (in German)

Carina Harms is new head of UBA's Central Office Division

As of 1 April 2025, Carina Harms is the new Head of the Central Office Division of the German Environment Agency (UBA). Previously, the political science graduate was head of the UBA’s “Administration and Services” Division, which is also part of the Central Office Division. read more (in German)

140 submissions for the German Prize for Nature Writing 2025

The submission period for the German Prize for Nature Writing 2025 is closed. There were 140 submissions in total. From poetry and essays to prose, a wide range of literary genres is once again represented and is now being scrutinised by the jury. read more (in German)

The share of renewable energies in gross electricity consumption rose to 54.4 per cent in 2024. This was the highest it has ever been.