Anyone dreaming of their own four walls is usually faced with the following question at the start: new or old building? If you decide to build a house, you can design it according to your individual wishes and ideas. A new building usually goes along with high costs and a long waiting period. For many people, the choice therefore falls on the second alternative – they simply buy an existing house. But be careful: the purchase price is usually not enough, especially with older buildings.
Renovating a house: This is how you should proceed
Around 50 percent of the total real estate stock in Germany consists of older buildings. Roughly speaking, this applies to houses that were built more than 50 years ago, i.e. before 1970. However, you should also not underestimate the renovation effort of younger houses. While you often have to reckon with structural problems such as rising damp, poor insulation and thin walls in pre-war buildings, it is not uncommon for more recent houses to have structural-chemical weak points. For example, the harmful substance asbestos was still permitted until 1993 and was thus used liberally in the construction of numerous houses.
Step 1: Take a close look at the current state of the building
If you want to buy a house or have inherited one, you should first put the property through its paces. While some defects, such as extensive mold growth or leaking windows, can be detected by laypersons, other problems can only be noticed by a trained eye. It is therefore essential to consult a real estate appraiser. Although a building expert can easily cost several hundred euros, he or she can save you from making expensive mistakes. If you forego the services of a surveyor and only discover serious defects after signing the purchase contract, your chances of success are rather slim.
A building expert will not only point out hidden weak points such as moisture in the walls, an outdated heating system or a dilapidated roof truss. He will also tell you which energy-saving renovation measures you are obliged to carry out under the Building Energy Act (GEG) and which subsidies you are eligible for. The expert will also inform you about the legal framework: If the building is a listed building, for example, you will have to comply with strict regulations.
The expert will also be able to give you an initial rough estimate of the cost, which can help you decide whether to renovate the house. Especially in the case of older buildings, renovation measures can easily amount to 60 percent of the purchase price. As a rule of thumb, you can remember: If the renovation is likely to cost more than three quarters of the purchase price, you'd better keep your hands off the property.
Step 2: Draw up a plan of action
Once you have listed all the defects and weak points with the help of the expert, you need to prioritize them. Here you should follow two golden rules:
- Always proceed from the outside inwards. Because renovation work always builds on each other. The new, energy-efficient heating system is of little use to you if the windows are poorly insulated and thus the cold penetrates from the outside.
- First work on the "real" defects and then take care of your wishes. Especially static-constructive as well as health-endangering deficiencies should be worked off first. Only when there is still money left over should you start on visual renovation measures such as new floors, a contemporary room layout or modern doors. If in doubt, these measures can be carried out at a later date.
When prioritizing your list of defects, also take into account all the measures that are necessary from an energy point of view. For example, the building energy law may require the replacement of old windows, insulation of the floor ceilings and roof insulation. If this applies in your case, you will have to carry out the appropriate renovation measures. Otherwise, you will be threatened with fines of up to 50.000 euros.
Step 3: Request offers
They now have a list of renovation work in front of them and also know which measures have top priority. On the basis of this action plan, you can now obtain offers from tradesmen. Do not hesitate to ask several craftsmen to compare the costs.
To reduce the cost of renovation, you should also consider whether you can do some of the work yourself. But don't overestimate your craftsmanship: While you can usually do the interior work yourself, you should call in a professional, especially for major repairs. This is advisable in terms of safety and warranty alone. If you make a mistake with more complex work, this can result in high follow-up costs.
Tip: You can deduct craftsmen's costs from your taxes. However, you may only claim the pure labor costs minus value-added tax and additional items such as travel expenses. However, the upper limit here is just 1.200 euros, which is why the tax advantage is unfortunately of little consequence in the case of a comprehensive building renovation.
Step 4: Financing
Last but not least, it's time to plan the budget. While you can now quantify relatively precisely what the necessary renovation measures will cost, you should leave a little buffer. Often, additional defects only become apparent during the work, resulting in further costs.
Also check whether you are entitled to state, regional or municipal subsidies. The German Federal Office of Economics and Export Control (BAFA) subsidizes individual energy-related measures by up to 10.000 euros. Through the KfW subsidy, you can also obtain low-interest loans specifically for the energy-efficient renovation of existing buildings. If you do not have the remaining amount on the high side, you can apply for a so-called modernization loan from your bank or another credit institution.
Renovation costs: cost examples and overview
It is not possible to make a general statement about the costs you should expect when renovating your house. Even the many renovation calculators that you can find online should only be considered as a rough guide. Basically, the cost of renovation depends on numerous factors, including:
- Age of the property
- structural and chemical condition of the property
- Size of the house
- Scope of the renovation measures
- desired visual measures and preferred equipment
Experts assume that you should expect to pay around 400 to 600 euros per square meter of living space for a complete renovation project. If you have to renovate a house, this can easily result in total costs in the middle to high five-digit range.
Average costs of individual renovation measures at a glance:
| Renovation measure | Average costs |
| Insulation of the roof | 50 to 90 euros per square meter of roof area |
| Renewal of the roof truss | 60 to 120 Euro per sqm roof area |
| Ceiling of the roof | about 100 Euro per sqm roof area |
| Insulation of the exterior wall | depending on the method, 100 to 200 euros per square meter of facade area |
| Facade painting | about 25 Euro per sqm facade area |
| Floor insulation | 30 to 50 Euro per sqm area |
| Window replacement | depending on the model about 500 to 1.000 Euro per window |
| Renewal of the electrical installation | 70 to 100 euros per square meter of living space |
| Replacement of the heating system | 7.500 to 25.000 euros |
In principle, there are hardly any upper limits to the refurbishment costs – especially if you attach importance to upscale equipment. New parquet flooring, modern designer radiators or an extensive smart home system can quickly push up the total cost of renovating and modernizing your building. Accordingly, it is important to draw up a precise financial plan in advance and to rank the measures according to their relevance and urgency.
Conclusion: A house renovation is an expensive undertaking
Do not fall with the house purchase on alleged bargain prices in. No matter how attractive the purchase price of your property may seem, if you need to core renovate the building, the cost of this endeavor can sometimes amount to as much as 60 percent of the purchase price. If you still want to buy an existing property, don't cut corners: Consult an experienced appraiser to help you quantify the likely cost of renovation as accurately as possible. This is the only way to rule out costly surprises from the outset.