Facing the challenge of making an old building more eco-friendly? Many owners underestimate the potential, but with the right measures, CO2 emissions can be significantly reduced and energy costs saved. This article shows you how to positively influence the environmental aspects of old buildings.
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The topic briefly and concisely
Older buildings are responsible for a significant portion of CO2 emissions, but they offer great potential for savings through renovation. [1]
Energy renovations (insulation, heating, windows) can reduce energy consumption by up to 85% and are subsidised by the government. [1,2]
The identification and removal of pollutants, as well as the use of sustainable building materials, are crucial for healthy and eco-friendly living in old buildings. [3,4]
Did you know that residential buildings in Germany are responsible for around 23% of CO2 emissions? [1] Older buildings present both challenges and enormous opportunities for environmental protection. Examining the specific environmental aspects of older buildings is therefore not only ecologically sensible but often also economically advantageous. From energy-efficient refurbishment to dealing with historic building materials, to the use of subsidies – this article highlights the key factors for a sustainable future in older properties and how you, as an owner, can benefit from them.
Increasing Energy Efficiency: The Key to Reducing CO2 in Older Buildings
The building sector accounts for about 35% of final energy consumption in Germany. [1] An energy-efficient renovation can reduce the energy consumption of an old building by up to 85%. [1] This not only benefits the environment but also significantly reduces your heating costs. Measures such as improved insulation and modern heating systems are crucial here. For example, since 2008, the specific final energy consumption for space heating in private households has decreased by 20%. [6] An energy-efficient modernisation is an important step. The EU Building Directive (EPBD) aims to reduce buildings' primary energy consumption by 16% by 2030. [5] Comprehensive renovation can cut the energy costs for an old house from several thousand euros annually to just a few hundred euros. [2] Thus, investing in energy efficiency is a direct contribution to climate protection.
Optimise thermal insulation: Reduce costs and protect the environment
Effective thermal insulation is the foundation for energy savings in older buildings. The costs for external insulation range between 100 and 150 euros per square metre. [1] This investment can pay off within about 10 years. [1] Roof insulation can increase the savings potential by 20–25%. [2] Facade insulation can even save 30–40% of heating energy. [2] Insulating the basement ceiling also contributes to energy savings by 5–10%. [2] There are various sustainable insulation materials available. Choosing the right insulating material and executing the work professionally are crucial for long-term success and reducing heat loss.
Updating heating systems: Efficient and eco-friendly heating
Outdated heating systems are often the primary cause of high emissions in older buildings. Replacing an old heating system can reduce energy consumption by 20-30%. [2] Heat pumps, which cost between 6,000 and 25,000 euros, produce only about 201 g CO2 per kWh. [1] Pellet heating systems are another option, costing between 10,000 and 16,000 euros with CO2 emissions of just 23 g CO2/kWh. [1] Government grants can cover up to 70% of the costs for a pellet heating system. [1] Solar thermal systems can also significantly reduce heating costs. [1] Switching to renewable energy is an important step. Remember that boilers put into operation before 1 January 1991 are no longer allowed to be operated. [1] Upgrading your heating system is an important step towards reducing the environmental impact of older buildings.
Renew windows and doors: Minimise heat loss
Old windows and doors are often significant weak points in the building envelope. Up to 12% of heat can escape through leaks. [1] Replacing them with modern, energy-efficient windows can save 10–20% on heating costs. [1] The costs for this range between 500 and 780 euros per window, depending on the frame material. [1] Triple-glazed windows can achieve U-values of 0.7 W/(m²K) or better. [1] Such an investment often pays for itself within 10 years. [1] The renovation of windows and doors is an important part of a sustainable refurbishment of old buildings. This not only improves the energy balance but also significantly increases living comfort.
Hazardous materials in old buildings: Identifying risks and professional removal
Older buildings can contain various harmful substances that may be hazardous to health. The most common include asbestos, artificial mineral fibres (AMF), polycyclic aromatic hydrocarbons (PAH), and formaldehyde. [3,4] Asbestos, for example, was commonly used in the 1960s and 1970s. [4] The cost of decontamination varies greatly; removing asbestos costs around €30–50 per square metre. [4] An initial assessment by experts can cost €300–400. [4] Proper disposal of hazardous materials is crucial for a healthy living environment. It is important to have suspect materials checked by professionals. Often, hazardous substances only become apparent during renovation work. [3]
The following harmful substances are commonly found in older buildings:
Asbestos (e.g., in roof panels, facade claddings, tile adhesives) [3]
Old mineral wool (AMF) as insulation (used until 2000) [4]
Polycyclic aromatic hydrocarbons (PAH) in adhesives or tar products [3]
Polychlorinated biphenyls (PCB) in joint compounds or paints (until the 1970s) [3]
Wood preservatives such as PCP and Lindane (often in roof trusses) [4]
Formaldehyde (e.g., in chipboard, paints) [3]
Heavy metals like lead (e.g., in old water pipes) [3]
A thorough analysis and, if necessary, remediation significantly improve the environmental aspects of old buildings and protect your health.
Use sustainable building materials: Building ecologically and durably
The choice of building materials has a significant impact on the environmental aspects of old buildings. Recycled construction materials like reused bricks or recycled concrete reduce raw material consumption and waste volumes. [1] According to the Federal Climate Protection Act, emissions should decrease by at least 65% compared to 1990 levels by 2030, with sustainable materials playing a key role. [1] Wood from sustainable forestry is an excellent choice for many applications. [3] For insulation materials, there are ecological alternatives such as wood fiber, cellulose, or hemp. [3] The use of environmentally friendly materials contributes to resource conservation. Pay attention to low-emission paints and plasters to promote healthy living conditions.
umweltaspekte-von-altbauten
There are numerous funding programmes available for the energy-efficient refurbishment of old buildings. The KfW banking group and BAFA offer low-interest loans and grants. [1] For individual measures, you can receive up to €30,000 per residential unit as a grant, or even €60,000 with the iSFP bonus. [1] With government funding, you can often save 20% of the renovation costs. [2] A complete refurbishment can save up to 90% of the costs for heating and hot water. [2] Inform yourself early about available funding. A professional energy consultation, which is often also subsidised, can help you find the right programmes and optimally improve the environmental aspects of your old building. Auctoa ImmoGPT can give you initial guidance here.
Know the legal framework and obligations
What are the biggest ecological challenges with older buildings?
The biggest challenges often include high energy consumption due to inadequate insulation and outdated heating technology, as well as the presence of pollutants from earlier construction phases. [1,3] Both negatively impact the environmental aspects of older buildings.
Is it financially worthwhile to carry out an energy renovation in an old building?
Yes, it is generally worthwhile. In addition to energy savings of up to 90% [2] and grants, the property value also increases. The payback periods are often between 10 and 15 years. [1,2]
What role does the Building Energy Act (GEG) play for older buildings?
The GEG sets minimum energy efficiency requirements for renovations and mandates the partial replacement of very old boilers. [1] It is a key regulatory framework aimed at improving the environmental aspects of older buildings.
Can I identify pollutants in an old building as a layperson?
The year of construction and previous renovations can provide clues. [3] However, accurate identification and assessment of pollutants should always be carried out by qualified professionals to avoid health risks and improper removal. [4]
What sustainable insulating materials are suitable for older buildings?
There are many ecological alternatives like wood fibre, cellulose, hemp or sheep wool. [3] These not only improve insulation but also the indoor climate and the environmental balance.
How can Auctoa help me with the environmental aspects of my older building?
Auctoa offers quick and neutral property evaluations. Our AI-supported analysis and ImmoGPT chat can help you assess the current status of your property and identify potential for environmentally friendly renovation.
Additional useful links
The KfW provides information on energy-efficient renovation of existing properties for private individuals.
The Umweltbundesamt provides information on energy-saving buildings.
The Statistical Office of Germany offers insights into the environmental behaviour of private households.
The dena (German Energy Agency) offers a fact sheet on energy retrofit, separating myths from facts.
The Federal Ministry for Economic Affairs and Climate Action informs about the energy transition in the building sector.
The Fraunhofer ISE publishes press releases on field test results that confirm the efficient operation of heat pumps even in older buildings.
The Consumer Centre offers information on renovating old houses to meet today's and tomorrow's standards.
FAQ
What are the biggest ecological challenges in older buildings?
The biggest challenges are often the high energy consumption due to poor insulation and outdated heating technology, as well as the presence of pollutants from earlier construction phases. [1,3] Both negatively affect the environmental aspects of older buildings.
Is it financially worthwhile to carry out energy-efficient renovations in older buildings?
Yes, it is usually worth it. In addition to energy savings of up to 90% [2] and incentives, property values also increase. The payback periods are often between 10 and 15 years. [1,2]
What role does the Building Energy Act (GEG) play for older buildings?
The GEG sets minimum requirements for energy efficiency during renovations and partly mandates the replacement of very old heating boilers. It is a key regulatory framework for improving the environmental aspects of older buildings.
Can I, as a layperson, identify pollutants in old buildings?
The year of construction and previous renovations can provide clues. [3] However, a safe identification and assessment of hazardous substances should always be carried out by qualified professionals to avoid health risks and improper removal. [4]
What sustainable insulation materials are suitable for old buildings?
There are many ecological alternatives such as wood fiber, cellulose, hemp, or sheep wool. [3] These not only improve insulation performance but also enhance indoor climate and environmental balance.
How can Auctoa help me with the environmental aspects of my old building?
Auctoa offers quick and impartial property valuations. Our AI-supported analysis and the ImmoGPT chat can help you assess the current status of your property and identify potential for eco-friendly renovation.
