Immobilien: Haussanierung – diese Maßnahmen bringen den größten Effekt

Winter brings significantly higher heating costs for homeowners. The primary cause is the sharp rise in gas and heating oil prices. Reduction of expenses doesn't necessarily require replacing the heating system at a high cost. "Even with affordable measures, it is possible to cut the existing heat energy consumption by several dozen percent," says Carsten Herbert.

Under the title "The Energy Savings Commissioner," he has run a YouTube channel for six years and recently published a book called "Einfach sanieren" with the Bundesverband Warentest. Currently, gas customers pay 13 cents per kilowatt-hour, up from nine cents last year. Heating oil now costs almost twice as much, at over 170 euros for 100 liters.

Immowelt reports that 41.3 percent of available residential properties are heated with gas, while 17.5 percent use oil heating in the basement. Although the share of both heating types has decreased over the past three years, fossil heating sources still dominate the market. To lower energy consumption before winter, focus on the following areas: Roofs - Insulation with minimal effort Older buildings lose a lot of heat through the roof.

Instead of a costly roof insulation and new roofing, there are more cost-effective insulation measures. Damping the top floor ceiling is particularly effective, especially in older buildings. It separates the upper full floor from the unheated roof or storage space above. Damping pays off almost always if no insulation layer with more than two centimeters has been installed yet.

This applies to almost all houses built in West and East Germany until the late 1970s that have not been renovated since. Average costs are 70 euros per square meter, with savings ranging from 70 to 250 kilowatt-hours per square meter per year. Damping a sloping roof is only worthwhile if the attic floor serves as living space and is heated.

Since the roof area is 30 to 40 percent larger than the top floor area due to the slope, the damping costs are higher with lower saving potential. Carsten Herbert estimates the costs of 70 to 90 euros per square meter and savings of 85 to 150 kWh per square meter per year. Walls - Insulation from inside and outside External wall insulation is considered particularly expensive.

With over 150 euros per square meter, homeowners need to pay a qualified specialist for a wall insulation system. Only 40 to 70 euros are needed for air-blown insulation from the outside in a two-layer wall construction. This type of insulation is commonly found in northern Germany and North Rhine-Westphalia. In the south, it is hardly prevalent.

In the north, houses with good technical condition often only benefit from internal insulation, either with wooden substructures or fiber insulation attached to inner walls. Alternatively, composite plates can be glued. Costs range from 40 to 90 euros per square meter, with savings of 80 to 100 kWh per square meter per year. Windows - Old windows with high heat loss Window heat loss depends heavily on the building's age.

Since 1995, triple-glazed glazing has been standard in Germany, while double-glazed windows were typically installed between 1970 and 1994. Older buildings often still have single-glazed windows or glass panes. Window replacement is the most logical measure, but also the most expensive. If the old window frames, including handles and mechanics, are in good technical condition, replacing the glazing may suffice.

Costs are between 180 and 250 euros per square meter, leading to a 200 kWh per square meter of living area savings per year. The rumor that denser windows lead to increased mold growth still persists in this context. For consumers, however, the problem lies in higher indoor air humidity, as new windows close tighter. More cost-effective and suitable for rental apartments are window films.

They can be glued directly onto the glass to reduce radiation heat leaving the room. Other films attach to the window frame and press against the inner glass, creating an air gap that acts like an additional pane. Costs are 15 euros per square meter, saving 75 kWh per square meter of living area per year. Further promotion: The state now covers the costs of heating system replacements.