Own or inherit an old house and fear the unknown renovation costs? Many owners underestimate the effort, which can quickly exceed €1,200 per square metre. This guide shows you how to check the renovation needs of your old house online and make a data-based decision.
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The topic briefly and concisely
New owners (including heirs) must renovate within two years according to GEG 2024, otherwise they face fines of up to €50,000.
The costs of a complete renovation often range from 400 to 1,200 € per square metre, depending on the condition and measures.
An individual renovation schedule (iSFP) receives government support and unlocks an additional bonus of 5% for many measures.
Are you facing the challenge of assessing the condition of an older property? Since 2024, the Building Energy Act (GEG) imposes clear deadlines, increasing the pressure on new owners. A lack of planning often leads to unforeseen expenses that diminish rather than enhance the value of your property. We guide you through a structured process that allows you to analyse the renovation requirements online, calculate costs accurately, and set the right priorities for value-adding modernisation. This way, you transform uncertainty into a clear strategy.
Legal Pressure to Act: The Building Energy Act (GEG) as the First Litmus Test
Since 1 January 2024, the revised Building Energy Act (GEG) sets clear guidelines for property owners. Especially in the case of a change of ownership through purchase, gift, or inheritance, there is an immediate obligation to act. You have exactly two years to carry out certain energy renovations. If these deadlines are missed, fines of up to 50,000 euros may be imposed. The obligation primarily affects properties that do not meet current efficiency standards. An initial review of legal requirements is therefore not an optional step but the financial and legal foundation for all further decisions. Non-compliance poses a significant risk of devaluation, which you can easily avoid through a proactive condition assessment. This makes the online assessment of renovation needs a necessity.
Digital Initial Assessment: Roughly estimate the need for renovation online
Before you hire expensive surveyors, you can make an initial assessment of the renovation needs online. Start by analysing available documents such as the energy certificate, which provides initial indications of energy weaknesses. The lifespan of individual components also provides insights into the need for action. A typical lifespan table shows that, for example, windows should be replaced after 20 to 40 years and a boiler after about 20 years. Online tools can provide a rough cost estimate based on these data, often ranging between €500 and €1,200 per square metre for a complete renovation. This initial analysis helps you understand the scope of the project. The following steps are essential for an initial online assessment:
Check the energy certificate: The efficiency class (A+ to H) is a direct indicator of the energy condition.
Analyse the year of construction: Houses from the 60s or 70s have different typical deficiencies compared to those from the pre-war period.
Use lifespan tables: Compare the age of the roof, heating, and windows with the average durability.
Use online calculators: Utilise free tools for an initial rough cost estimate of the renovation measures.
This digital groundwork lays a solid foundation for detailed professional planning in the next step.
Costs in Detail: What Renovations to Roof, Facade, and Heating Really Cost
A rough estimate is not enough to ensure financial security. The costs of renovating an old building vary significantly depending on the measures and condition. A new roof covering can cost between €80 and €300 per square metre, while facade insulation ranges from €60 to €250 per square metre. Replacing the heating system is one of the largest single investments, costing between €9,000 and €35,000, but it can be reduced by up to 70% with funding. Do not underestimate the technical dependencies: A new heating system is inefficient in an uninsulated house. A professional renovation cost calculation takes these factors into account. Investing in triple-glazed windows at around €500 each often pays off through the savings on heating costs within a few years. A detailed cost breakdown is the key to prioritising the measures.
The Strategic Path: Using the Individual Renovation Roadmap (iSFP) for Promotion
The individual renovation roadmap (iSFP) is the tool of choice for optimally planning renovation measures and maximizing government subsidies. A certified energy efficiency expert analyzes the current condition of your property and creates a tailored concept. The costs for an iSFP range from approximately €1,300 to €2,100, with the Federal Office for Economic Affairs and Export Control (BAFA) covering up to 50% (maximum €650). The decisive advantage: If you implement a measure recommended in the iSFP, you receive an additional subsidy bonus of 5% on the respective measure. This increases the subsidy for facade insulation from 15% to 20%, making the investment significantly more profitable. The iSFP is therefore not just a plan, but a direct lever for reducing your renovation costs.
Increasing value as a goal: Maximising the return on investment of every measure
Every renovation should not only improve living comfort but also increase the value of your property. An energy-efficient renovation can raise the sale value by up to 25%. Properties with poor energy ratings, on the other hand, experience price reductions of up to 30%, and in rural areas even up to 50%. It is crucial to prioritise measures with the highest return on investment. These typically include:
Heating modernisation: Switching to renewable energies is highly subsidised and reduces operating costs by over 30%.
Insulation of the building envelope: A well-insulated façade or a renovated roof can reduce energy loss by up to 40%.
Window replacement: Modern windows not only improve energy efficiency, but also enhance soundproofing and security.
A data-driven analysis, like the one Auctoa offers with ImmoGPT, helps you identify the most value-enhancing measures. This ensures that your investment yields a measurable return.
Conclusion: Effectively manage renovation needs with a data-driven strategy
Assessing the renovation needs of an old house online is the first step to avoiding costly surprises and fulfilling legal obligations. A systematic approach – from the initial digital analysis through detailed cost calculation to strategic iSFP – transforms uncertainty into a clear action plan. This not only ensures compliance with GEG requirements but also sustainably increases the value of your property. A well-founded, neutral assessment is the compass that safely guides you through the complex renovation process.
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Additional useful links
Statistisches Bundesamt provides information on construction price indices and real estate price indices.
Statistisches Bundesamt explains the methodology for calculating the construction price index.
Deutsche Energie-Agentur (dena) offers a renovation study on single-family homes.
Verbraucherzentrale provides information on energy-efficient renovation of old buildings.
KfW gives an overview of their funding products for existing properties.
KfW provides information on energy-efficient renovation.
Bundesamt für Bauwesen und Raumordnung (BBR) offers a search form for construction projects.
Sprengnetter publishes a blog article on the state of renovation in Germany.
Deutsche Handwerks Zeitung offers an article about the cost of craftsmen's hours.
FAQ
How can I check the renovation requirements online if I don't have an energy performance certificate?
Without an energy performance certificate, you can use online calculators that provide an initial estimate based on the year of construction, building type, living area, and known condition. However, for a precise analysis and to fulfill the obligations of the GEG, obtaining an energy performance certificate from a certified expert is indispensable.
What is the difference between a refurbishment and a modernisation?
A renovation fixes defects and restores the original condition (e.g., repairing a leaky roof). A modernisation improves the property's standard beyond its original state, often with a focus on energy efficiency or living comfort (e.g., installing a heat pump).
What role does the individual renovation roadmap (iSFP) play in financing?
The iSFP is often a prerequisite for obtaining loans and grants from KfW or BAFA. It serves as proof of a well-thought-out plan for banks and increases the chances of receiving a financing commitment. In addition, it unlocks the iSFP bonus of 5% for many funding programs.
Do I also have to renovate if I live in the inherited house myself?
Yes, the renovation obligation under GEG also applies to heirs who move into the house themselves. The exemption for long-term owner-occupiers only applies if you have already lived in the house yourself before the deadline of 1 February 2002, which is generally not the case with a recent inheritance.
How do I find a qualified energy consultant for the iSFP?
You can find qualified experts who are approved for funding programs in the Energy Efficiency Experts List (EEE list) of the German Energy Agency (dena). Only consultants from this list are allowed to issue an eligible iSFP.
Is renovation worthwhile even if I'm not planning to sell?
Yes, absolutely. An energy-efficient renovation significantly reduces your monthly energy costs, enhances living comfort through a better indoor climate, and protects the building structure from moisture and mould. Additionally, it is an investment in the sustainability and long-term value retention of your property.
