Modernise your period property with energy efficiency: Reduce costs, increase value, secure the future
Do you own an older building and wonder how to make it future-proof? An energy-efficient renovation can reduce your heating costs by up to 90% and significantly increase the property's value. Discover the most effective strategies and most lucrative funding opportunities for your project here.
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The topic briefly and concisely
An old building renovation can reduce energy costs by up to 90% and is subsidised by the government with up to 70% for individual measures.
An individual renovation roadmap (iSFP) is recommended because it offers an additional funding bonus of 5% and allows for higher eligible costs.
The Building Energy Act (GEG) sets clear deadlines and requirements for renovations, particularly when older properties change ownership.
The decision to retrofit an old building to be energy efficient is a significant step. Many property owners are facing increasing energy costs and the desire for more sustainability. By 2045, all buildings in Germany are expected to be climate-neutral, which increases the pressure to act. A comprehensive renovation can drastically reduce energy costs—often by up to 90%. This article shows you which measures have the greatest impact, how to take advantage of government support of up to 70% for individual measures, and how Auctoa can assist you with assessment and planning. An Auctoa assessment helps you accurately evaluate the potential of your property.
The essentials: Your quick overview
The energy-efficient renovation of your old building offers enormous benefits. You can reduce your heating costs by up to 90%. At the same time, you significantly increase the value of your property. Government grants often cover 20% of the renovation costs, and in some cases, up to 70% when replacing heating systems. An individual renovation roadmap (iSFP) secures you an additional 5% funding bonus.
Why act now? The urgency of energy-efficient refurbishment of older buildings
The building sector accounts for about one-third of greenhouse gas emissions in Germany. Many old buildings, often constructed before 1979, have hardly been renovated for energy efficiency and consume several times the energy compared to new buildings. The Building Energy Act (GEG) requires a climate-neutral building stock by 2045. Buyers of properties built before February 2002 are obliged to renovate within 2 years if standards are not met. Act now to save costs and comply with legal requirements. Sustainable land use begins with energy efficiency. Modernizing outdated heating systems, which on average are over 17 years old, is an important step. This is not only a matter of cost but also of the future viability of your property.
Costs and efficiency: What do you invest, what do you save?
The costs of renovating an old building vary greatly, from four-figure sums to over €170,000 for extensive measures. Roof insulation costs about €100 to €250 per square metre and can save 20–30% of energy. Façade insulation costs €100 to €250 per square metre with a savings potential of 30–40%. Replacing old windows costs between €500 and €1,200 per window and saves 7–20% energy. A new heating system can cost between €20,000 and €35,000 but can reduce heating costs by 20–30%. Despite high initial investments, many measures pay for themselves through subsidies and energy savings often within 10 to 15 years. A detailed analysis of renovation costs is crucial beforehand. Investing in energy efficiency is a direct investment in lower operating costs.
Make the most of state subsidies: Grants and loans for your renovation
Extensive funding is available for the energy-efficient renovation of older buildings. The Federal Funding for Efficient Buildings (BEG) is central here. You can receive grants through the BAFA:
15% basic funding for measures on the building envelope (insulation, windows), with eligible costs up to 30,000 euros.
An additional iSFP bonus of 5% increases the funding rate to 20% and the eligible costs to 60,000 euros per residential unit.
The maximum grant for the building envelope is therefore 12,000 euros.
The KfW is responsible for heating subsidies (Programme 458) and loans:
Up to 70% subsidy for replacing heating systems (max. 21,000 euros with 30,000 euros eligible costs).
This consists of 30% basic funding, 20% speed bonus, 30% income bonus, and 5% efficiency bonus.
Loans up to 150,000 euros (KfW 261) with repayment bonuses ranging from 5–45% for efficiency houses.
Supplementary loans (KfW 358) up to 120,000 euros for individual measures.
Alternatively, 20% of renovation costs (up to 40,000 euros) can be deducted from taxes over three years. The application for funding must be submitted before starting any work. An overview of green funding options can assist you. The right combination of funding can significantly reduce the financial burden.
The most effective remediation measures in detail
To modernise an old building energy-efficiently, a well-thought-out sequence of measures is crucial. Typically, one starts with the building envelope. Roof insulation can reduce energy consumption by up to 30%. Insulating the façade is also very effective, with savings of up to 40%. Insulating the top storey ceiling (up to 20% savings) and the basement ceiling (up to 10% savings) also contribute significantly to reducing heat losses. Replacing old windows with modern triple glazing can reduce heat loss through windows by up to 80%. Only after optimising the building envelope should the heating system be renewed. A new heating system, adjusted to the lower heat demand, such as a heat pump in combination with renewable energies, then operates at maximum efficiency. The renovation of environmental aspects of old buildings is a complex topic. Each measure builds on the previous one to achieve maximum efficiency.
The individual renovation roadmap (iSFP): Your tailored path to efficiency
An individual renovation roadmap (iSFP) is a valuable tool for energy-efficient modernization of old buildings. It is created by a certified energy consultant following an on-site analysis. The iSFP outlines the current energy status of your property and proposes specific, coordinated renovation steps. The creation of an iSFP is subsidized by BAFA with up to 80% of the costs (maximum 1,300 euros for single/two-family homes). A key advantage: With an iSFP, you receive an additional bonus of 5% for many BAFA renovation measures. Furthermore, the maximum eligible costs for these measures often double from 30,000 euros to 60,000 euros. Thus, the iSFP not only provides a clear roadmap but also significantly increases your funding options. It helps you systematically implement energy efficiency. This plan is your compass for a successful renovation.
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The Building Energy Act (GEG) forms the legal basis for energy-efficient refurbishment. It sets requirements for new buildings and renovation measures. A central goal is the climate neutrality of all buildings by 2045. This results in specific obligations for owners of older buildings:
Obligation to replace oil and gas boilers (standard and constant temperature boilers) that are over 30 years old.
Requirement to insulate the top storey ceiling or the roof if the minimum thermal protection is not met.
Insulation of uninsulated, accessible heating and hot water pipes in unheated rooms.
When renovating more than 10% of a component (e.g. facade), it must meet the current GEG requirements.
Since January 2024, newly installed heating systems must be operated with at least 65% renewable energy.
Buyers of older properties (built before February 1st, 2002) that do not meet these standards have two years to retrofit. Ignorance does not protect against potential fines of up to 50,000 euros. Learn about your obligations when buying a house and climate protection. Complying with these regulations ensures the value of your property.
Auctoa: Your Partner for Valuation and Strategic Restructuring Consulting
How much energy can I save through renovating an old building?
A comprehensive energy-efficient renovation can reduce your costs for heating, cooling, and hot water by up to 90%. Individual measures such as roof or facade insulation already bring savings of 20-40%.
Is an individual renovation roadmap (iSFP) worthwhile?
Yes, an iSFP is subsidised by the government (up to 80% of the consulting costs) and secures you an additional bonus of 5% on many BAFA funding measures. In addition, the maximum eligible costs often increase.
Which heating system is best for a renovated old building?
After good insulation, heat pumps (possibly with surface heating), pellet heating systems, or hybrid systems are often suitable. It is important that the new heating system is operated with at least 65% renewable energy to be eligible for funding.
Do I need to apply for funding before starting the renovation?
Yes, for most BAFA and KfW funding programmes, applications must be submitted and approved before concluding delivery or service contracts, i.e., before the measures begin. An exception is the tax subsidy.
What happens if I don't meet the renovation obligations of the GEG?
Failure to comply with the renovation obligations under the Building Energy Act (GEG), especially after a change of ownership, can lead to fines of up to 50,000 euros. Compliance is checked by authorities and chimney sweeps.
How can Auctoa help me with my old building renovation?
Auctoa offers AI-powered property evaluations that help you assess the value of your property before and after renovation. We provide data-driven recommendations and support you with neutral analyses for your strategic decisions. Contact us for an evaluation or use our ImmoGPT chat.
Additional useful links
The Federal Environment Agency offers comprehensive information on energy-efficient buildings and energy-saving measures.
The Federal Ministry for Economic Affairs and Climate Action (BMWK) provides current figures on energy efficiency in Germany.
The Federal Statistical Office (Destatis) provides information on construction prices and the property price index in Germany.
The Construction Cost Information Centre of the German Chambers of Architects (BKI) offers detailed cost data for refurbishment measures in older buildings.
The WWF highlights the financial profitability of energy renovations in a study.
The KfW (Kreditanstalt für Wiederaufbau) offers comprehensive information on funding programmes for energy-efficient refurbishments.
FAQ
How much energy can I save by renovating an old building?
Through a comprehensive energy renovation, you can reduce your energy costs for heating, cooling, and hot water by up to 90%. Individual measures such as roof or façade insulation already bring savings of 20–40%.
Is an individual renovation roadmap (iSFP) worthwhile?
Yes, an iSFP is subsidised by the government (up to 80% of the consultancy costs) and provides you with an additional bonus of 5% on many BAFA funding programs. Furthermore, the maximum eligible costs are often increased.
Which heating system is best for a renovated old building?
After good insulation, heat pumps (possibly with underfloor heating), pellet heating systems, or hybrid systems are often suitable. It is important that the new heating system operates with at least 65% renewable energy to qualify for funding.
Do I need to apply for funding before starting the renovation?
Yes, for most funding programmes from BAFA and KfW, applications must be submitted and approved before the conclusion of contracts for delivery or services, that is, before the start of measures. An exception is tax incentives.
What happens if I don't fulfil the renovation obligations of the GEG?
Non-compliance with the renovation obligations under the Building Energy Act (GEG), especially after a change of ownership, can result in fines of up to 50,000 euros. Compliance is monitored by authorities and chimney sweeps.
How can Auctoa help me with my renovation of an old building?
Auctoa offers AI-powered property valuations that help you assess the value of your property before and after renovation. We provide data-driven recommendations and support you with unbiased analyses for your strategic decisions. Contact us for a valuation or use our ImmoGPT chat.
