Study demonstrates environmental benefits of energetic re-furbishment for buildings

  • Joint study with the Wuppertal Institute
  • Including the utilization phase, energetic refurbishments generate just 50% of the carbon footprint of a new building
  • Electrification of heating systems must be accelerated to reduce dependency on fossil fuels
  • LEG is well positioned with its climate policy on carbon neutrality by 2045 and its own projects regarding serial modernization, energy transformation and user contribution

Climate protection is one of the most important challenges facing society. The German federal government recently announced its plans to invest about EUR 200 billion in climate protection by 2026. In the real estate industry, the main focus is on sustainable construction and renovation to reduce CO2.

In light of this, the housing company LEG commissioned the prestigious Wuppertal Institute to assess the environmental impact of energetic refurbishments and new construction projects. The study focused on material requirements, primary energy consumption and the associated greenhouse gas emissions. The full results of the study are now available.

Using a comprehensive set of data on buildings from three relevant age groups in the LEG property portfolio, the Wuppertal Institute analysed the carbon footprint in the life cycle of a new building compared to that of refurbishing an existing property. This was based on the buildings’ various structural features such as the period of construction, the number of apartments, the number of floors, the roof shape, the wall construction and living space.

The study found that when the CO2 costs for putting up new buildings are taken into account, energy efficiency energetic refurbishments result in just half the carbon footprint of a new build. While new buildings certainly have a social value, as they help correct the imbalance between supply and demand, they are not an alternative to modernising existing properties from an environmental perspective. In other words, new builds are required where there is demand for addition-al housing. Tearing down and building again is generally counter-productive when it comes to climate protection and is not a solution for total housing stock in Germany.

However, the study also showed that the move towards the electrification of heating systems, for example using heat pumps, still needs to be accelerated significantly, thereby reducing dependency on fossil fuels.

The key factors here are the speed at which this can be put into practice and cost efficiency. LEG takes this approach and has initiated a wide range of projects. Serial modernisation is particularly important here to keep the costs for tenants, the environment and society as low as possible.

As well as the “Energiesprong” project in Mönchengladbach-Hardt, LEG also runs other initiatives of its own to address the issue. Other projects, such as testing decentralised energy supply with a biomass power plant in Siegerland, continuing to connect our properties to the district heating network and testing various measures to change user behaviour, are also part of LEG’s climate strategy. The path to achieving carbon neutrality also requires a large supply of green energy, for example for the use of heat pumps. Solar panels on roofs are not nearly enough, and we need to be open to technology in order to invest money in measures that reduce CO2 the most. This, alongside other projects, some of which are still at the planning stage, provides helpful insights for the entire housing industry to significantly improve the climate footprint.

“Serial modernisation is a vital component of our ESG strategy and will contribute between 25% and 30% to CO2 reduction in the move towards carbon neutrality. Firstly, this is crucial for the efficient use of new energy technologies such as heating pumps, but it is also the more suitable way of achieving climate targets and keeping housing affordable,” said Lars von Lackum, CEO of LEG Immobilien SE. “Accordingly, we far exceeded our goal for the financial year of carrying out energy efficiency upgrades in 3% of our properties, renovating a total of 3.5%.”

“The study demonstrates the environmental advantages in energetic refurbishments of existing buildings compared to tearing down existing properties and building new ones,” said Sören Steger, a senior researcher in material cycles and the project manager of the study at the Wuppertal Institute. He added: “Taking account of the entire life cycle, however, the results also show the need to transition heat and hot water supply away from fossil fuels and towards district and local heating and efficient heat pumps and green energy.”

LEG published its ESG strategy in 2021. In line with the German Climate Change Act, it sets a target of carbon neutrality by 2045. Energy efficiency upgrades at existing properties are to account for between 25% and 30% of the CO2 reduction, the use of green energy and heat between 65% and 70% and tenants up to 5% by way of optimised usage.

You can find the entire study “Energetic refurbishment of existing buildings or new construction – ecological assessment in terms of material requirements, primary energy consumption and the associated greenhouse gas emissions” here.

Your contact:
Mischa Lenz, tel. +49 2 11 / 45 68-117

About LEG
With more than 166,000 rental properties and around 500,000 residents, LEG is one of Germany’s leading listed housing companies. The company has eight branch offices and is represented by local personal contacts at selected locations in other Western German states. LEG generated income of around EUR 960 million from its core rental and lease business in the 2021 financial year. As part of its new construction campaign, LEG wishes to make a social contribution towards creating both privately financed and publicly subsidised housing, and to build or acquire at least 500 new apartments per year from 2023 onwards; the number of new apartments is to rise to 1,000 in total from 2026.
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