Home generalCore renovation: Costs per square meter in the old building | Cost Table

Core renovation: Costs per square meter in the old building | Cost Table

  • Receive instead of new construction
  • structural restoration
    • foundation
    • insulation
    • top, roof
    • Save up
    • Cost Overview

Just because a house is prone to repair or technically outdated, it does not have to be a case for the wrecking ball. Often an older house can still be saved if the right measures are taken. If certain key points are still intact, much can be achieved. The technical possibilities for this are very astonishing: Many things that would have been unrepeatable just a few years ago can now be handled well thanks to modern means. Read in this text what you need to look out for when renovating a historic building.

Receive instead of new construction

Give the old building a chance - the golden rule

The "golden rule" in the core renovation is: The renovation costs may make up 50% of the purchase price of a property, then it can be worthwhile. Of course, this only applies to areas with no rapid price decline in real estate. Even today, many extremely cheap houses can be bought in East Germany.

Here, of course, more money can be taken in hand, to turn a half-ruined manor or Resthof again a really chic home . In economically normal or booming regions, however, the 50% rule should be respected. Above all, if property prices tend to rise, a smartly planned new building usually pays off rather than a completely renovated old building .

structural restoration

Typical traps

Old buildings essentially have a common enemy: moisture. Damaged supply or sewage pipes, damp cellars, leaky roofs or lack of insulation - water in the house always has the same consequences: creeping, steadily worsening damage to the building fabric plus mold and rot on all organic material. On the roof, a leaky roof tile can cause the rotting of a whole roof truss.

In the basement, mistakes and holes in the seal make the foundation crumble. Damaged facades create a dull, damp room climate, which attacks the furniture. Therefore, before deciding to buy or refurbish, the entire building should be inspected for moisture penetration. After a preliminary inspection by the potential new landlord, it is also strongly recommended to consult a specialist.

Humidity damage can be recognized as follows:

top, roof

  • rotting beams and rafters
  • Moisture stains on the inner formwork
  • musty smell


  • wet spots
  • unpleasant room climate
  • musty smell

TIP: Be sure to hang pictures and move cabinets forward. Frequently, damp and moldy nests form there.

basement, cellar

White efflorescence or black mold on the brickwork, strong, musty odor. Beware, with progressive damage threatens a danger for the statics!

After an initial assessment by the interested party, an external expert can provide clarity. With the help of special measuring devices, the water in the masonry is checked exactly. Subsequently, the further measures can be calculated.


The foundation has to fit

The most important thing about the house is the foundation . Everything else can be tiptop in order, without a stable foundation and robust basement walls, the house is irrecoverably lost.

Therefore: A core renovation always takes place from "bottom to top". A roof can be seen relatively easily and necessary investments can be delayed a bit. But the basement and foundation must be in good condition, otherwise you quickly burn a lot of money.

Fortunately, it is no longer the case that the whole house has to be excavated for the renovation of a basement wall. In many cases, a leaky basement can be repaired and made homely by a minimally invasive injection procedure. That's one thing for a specialty company though.

But at least: This measure happens inside the house. A mini excavator to excavate the basement foundations does not have to be ordered. Similar methods are also available today for retrofitting a moisture barrier . This can be repaired even heavy construction errors.


Facade insulation - inside or outside ">

Listed house

A completely different challenge is to renovate a listed building or an old building with a beautiful, well-preserved façade. If a beautiful truss, an orementreicher stucco or other, beautiful and classic applications adorn a facade, an external insulation is a real building sin . For listed buildings, the application of external insulation is even prohibited. The solution is called - internal insulation. It's not that cheap.

It stands to reason that an internal insulation can not be done with polystyrene. The risk of fire is far too high. In addition, the rigid foam panels are not entirely harmless to health. Finally, their disposal has become very expensive. The only material that can be considered for permanent and correct refurbishment of a listed old building for internal insulation are calcium silicate panels.

These are essentially micro-foamed lime. The manufacturing process of calcium silicate boards are very complex, which makes the products very expensive. However, for a number of reasons, the panels are ideal for permanent renovation.

They offer the following advantages:

  • very good insulation values
  • natural, non-flammable, emission-free material
  • very good fire protection
  • very breathable and binding for moisture
  • regulates the room climate
  • easy to dispose of


A downside to the many advantages of calcium silicate panels is the price: At least 30 euros per square meter you have to expect. However, interior insulation with calcium silicate is a permanent measure that also significantly increases the value of a property.

top, roof

Dense roof, healthy house

The roof tile made of baked clay dominates until today the roofing of a building. The only alternatives are natural slate and in certain regions wood-beaver's tails or thatch. These natural substances all have one common drawback: they last only for a limited time. By coating the lifetime of a roofing can be significantly extended. Still, once the first pan has jumped, you have to act. Otherwise, insulation and, in the worst case scenario, the roof truss will soon be a case for the refurbishment.

If the local building regulations permit, however, an alternative to the roof tile can be considered for the new roofing. Today, textured trapezoidal sheets are available that look deceptively similar to a shingled roof. In contrast to the small but heavy roof tile made of clay, these lightweight sheets are delivered in up to seven meters in length. This makes assembly much faster and easier. For sheet metal roofs but must be done a thorough sound insulation, otherwise it can be very loud at the next rain.

Save up

Save with new installation

The fabric of a house is one thing - the installation the other. Again, reviewers should get an accurate picture of the situation.

The recommendation is: If you have to redevelop, then you should do it thoroughly and correctly. Patchwork and embroidery do not really increase the value of a home.

It is better: If the sewage and Zuwasserleitungen are defective at one point - all out and make new. So you get a defined new condition, which in the case of a sale of the house adds value.


The same applies to the installation. Old pipes of inferior material can get a brittle insulation over time. In addition, you never know what surges the power grid in the house had to endure. As a result, a small amount of damage may always have formed, which drives up electricity costs by means of creeping current or even creates life-threatening spots.

The advantage here is that the handyman can work very hard on his own . Lifting slots, drilling holes for sockets and cutting, stripping and laying cables are all work that you can do yourself. As a rule, this is done on a weekend for a normal family home. The wiring of switches, sockets and especially fuses should then be left to the skilled person.

Take the opportunity of the core refurbishment

Even if a core refurbishment involves a lot of work and dirt - it also offers unique opportunities. Easier and easier than at this time, new heaters, including underfloor heating, can not be installed. Once the house is plastered and decorated again, no one tears the screed out again.

It's better to plan ahead and divide your budget so that you do not miss those opportunities. New heating systems, such as pellet heaters or solar collectors, can also be installed very easily in the course of a core refurbishment. These measures also considerably increase the value of an old building.

Cost Overview

Core renovation of the old building - a cost overview

Here we have summarized the most common costs in a table with which you have to reckon with the refurbishment of an old building.

No old building purchase without appraiser

In sum, the following picture emerges: Buying an old house without an appraiser is an incalculable risk . What begins with picking at one place can quickly end in burning incalculable buzz. It is quite fatal if tens of thousands of euros have been invested and then the demolition is inevitable. This can be saved very well if the house was previously thoroughly inspected by an appraiser.

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