Property Valuation
Renovation Potential Report
Costs for a complete renovation online calculator
Are you facing the decision of a complete renovation and fearing skyrocketing costs? Many online calculators only provide a rough estimate, often deviating by 30%. This guide shows you how to accurately analyse the costs of a complete renovation, avoid pitfalls, and increase the value of your property by over 20%.
With access to Google, BORIS, and Deep Research.
The costs for complete renovation typically range between 800 and 2,000 euros per square meter, depending on the condition of the existing building.
Always plan a financial buffer of at least 15-20% for unforeseen costs such as asbestos or moisture damage.
State funding from KfW and BAFA can reduce renovation costs by up to €67,500 through grants and low-interest loans.
Wondering if the estimate from an online calculator for the costs of your major renovation is really accurate? Renovating an old building is one of the largest investments for property owners, where costs can quickly rise from €800 to over €2,000 per square metre. Poor planning often leads to refinancing and jeopardises the profitability of your project. We provide you with a data-driven method to maintain control from the initial cost estimate to final acceptance, uncover hidden costs, and secure government grants of up to €67,500. This way, you can transform your property into a stable and future-proof asset.
The first question in any complete renovation is: What will it cost? An online calculator for renovation costs provides an initial guideline, but the actual numbers depend greatly on the condition and type of property. For an old building, you should expect costs between 800 and 2,000 euros per square metre. In the case of a very poor condition or high-end fittings, costs can even rise to up to 2,500 euros per square metre. For a 150 m² property, this means an investment range of 120,000 to 300,000 euros. A detailed analysis of renovation costs is therefore the first step. This basic calculation is crucial before we examine the specific cost drivers in more detail.
After the rough estimate per square meter, the main cost drivers need to be identified, as they can account for up to 70% of the total budget. Having a precise understanding of these items is crucial for realistic budget planning.
Here are the seven key areas whose renovation significantly influences the costs:
Roof renovation: A new covering, including insulation, costs between 150 and 300 euros per square meter of roof area.
Heating system: Replacing an old system with a modern heat pump can cost between 25,000 and 40,000 euros.
Windows and exterior doors: Expect to pay 750 to 1,500 euros per window, depending on the material and glazing.
Electrical installation: Completely renewing the electrics costs around 100 to 190 euros per square meter of living space.
Water and sewage pipes: Replacing all pipes, including wall and floor work, can cost between 8,000 and 15,000 euros.
Facade insulation: An external thermal insulation composite system (ETICS) costs between 100 and 200 euros per square meter of facade area.
Bathroom renovation: A completely new bathroom requires a budget of at least 15,000 to 30,000 euros.
The costs of an energy-efficient renovation are considerable, but they also offer the greatest potential for value increase and savings. Aside from these predictable expenses, unforeseen costs often lurk beneath the surface.
What no online calculator for core renovation costs can account for are the unforeseen defects that only become visible after work begins. Particularly in older buildings constructed before 1990, issues such as dampness in the basement, asbestos contamination, or decayed wooden beams frequently occur. These "surprises" can quickly exceed the planned costs by 20-30%. Therefore, be sure to include a financial buffer of at least 15%, preferably 20%, of the total costs. With a budget of 150,000 euros, this corresponds to a reserve of 30,000 euros. A professional assessment of the renovation needs in advance can halve this risk. With a secured budget, you can further optimise financing through government assistance.
The high investment costs of a full renovation can be significantly reduced through targeted government subsidies. The Kreditanstalt für Wiederaufbau (KfW) and the Bundesamt für Wirtschaft und Ausfuhrkontrolle (BAFA) are your key contacts in this regard. For comprehensive renovation to meet efficiency standards, the KfW offers a loan of up to 150,000 euros per residential unit under Program 261. Additionally, you can receive a repayment grant of up to 45%, equivalent to a reduction of the loan amount by up to 67,500 euros. For individual measures such as window replacement or insulation of the building envelope, the BAFA grants subsidies of up to 20%. It is important to submit applications before starting the measures. A professional funding check ensures that you don't miss out on any money. But how reliable are the tools that provide an initial cost estimate?
A cost calculator for a complete refurbishment is a useful tool for an initial rough cost estimate. Such calculators use statistical averages for various trades and provide you with an initial figure within minutes. However, their accuracy is limited. Most online tools cannot account for the individual condition of your property, regional price variations for craftsmen, or the quality of materials. Consequently, the discrepancy between the calculated costs and reality can be 30% or more. Use these calculators as a starting point, but never as the sole basis for your financial decision. For a precise analysis, a detailed renovation potential report based on the specific data of your property is essential. Ultimately, the investment is not just about the costs, but about the value creation achieved with it.
A major renovation is not just an expense, but an investment in the future value of your property. A high-quality renovated property can experience a value increase of 20 to 30%. Measures to improve energy efficiency are particularly worthwhile. A house with an energy certificate of class A or B achieves a sales price on the market that is up to 25% higher than a comparable property of class G. Therefore, the focus should not only be on aesthetics but also on technical and energy modernization. A well-thought-out renovation before sale enhances the appeal to buyers willing to pay more for lower ancillary costs and high living comfort. The right strategy turns high renovation costs into a profitable added value.
A cost calculator for a core renovation provides a valuable initial orientation, but does not replace detailed planning. The key to a successful core renovation lies in a structured approach: start with a realistic cost estimate of 800 to 2,000 euros per square metre, identify the main cost drivers, and plan a buffer of 20% for unforeseen expenses. Use government grants to relieve your budget by up to 67,500 euros. Consider the renovation not as a cost factor, but as a strategic investment that can increase the value of your property by up to 30%. A data-driven analysis, as offered by Auctoa with the ImmoGPT, protects you from costly wrong decisions. A well-planned renovation is the surest way to a value-stable and future-proof property.
The Federal Statistical Office offers comprehensive information on construction prices and the real estate price index.
Detailed data on the construction price index is available on the Federal Statistical Office website.
Frequently asked questions on the construction cost index are answered by the Federal Statistical Office in its FAQs.
The Federal Statistical Office provides specific price indices for residential buildings.
The KfW informs private individuals about the possibilities and benefits of energy-efficient renovation of existing properties.
A detailed overview of funding products for the energy-efficient renovation of existing properties is offered by the KfW.
Current tables and data on construction prices and the real estate price index are available on the Federal Statistical Office website.
Can I deduct the costs of a full renovation from my taxes?
As a landlord, you can claim the costs of a full renovation as maintenance expenses over several years for tax purposes. For owner-occupiers, tradesman services are deductible up to an amount of 1,200 euros per year (20% of a maximum of 6,000 euros in labor costs). However, receiving KfW or BAFA grants usually excludes tax deductions for the same measure.
How long does a full renovation take?
For an average detached house, a full renovation typically takes between six and twelve months. The exact duration depends on the scope of the work, the coordination of the trades, and unforeseen complications.
Is a full renovation worthwhile for an inherited property?
Whether a full renovation is worthwhile depends on the market value, location, and condition of the inherited property. Renovation can significantly increase the sales value or allow for profitable renting. A data-driven analysis, such as the one offered by Auctoa, helps you make the most economical decision between renovating, selling, or renting.
What is the difference between renovation, refurbishment, and modernisation?
Refurbishment is purely cosmetic (e.g., painting). Modernisation improves the living standard (e.g., new bathroom). Renovation restores the original condition and removes defects (e.g., roof repair). Full renovation is the most comprehensive form and renews the building down to the supporting structure.
What role does the energy certificate play in renovation?
The energy certificate is essential. It documents the energy condition before the renovation and the standard achieved afterwards. A significant improvement in energy efficiency class (e.g., from G to B) is a key driver for value enhancement and often a prerequisite for receiving funding.
How can Auctoa assist with my renovation decision?
Auctoa provides an objective, data-supported basis for decision-making with ImmoGPT and detailed renovation potential reports. We analyse the condition of your property, estimate renovation costs more precisely than any standard online calculator, and calculate the expected value increase. This allows you to make informed decisions about which measures are truly worthwhile for you.
