Thermal renovation and boiler replacement always pay off

The results of a new calculation by the engineering firm e7, which specializes in energy and environmental technology, on the subject of thermal home refurbishment and replacing old boilers show that, despite the lack of nationwide subsidies, investments pay off and homeowners can save between 85,000 and 130,000 euros in the long term through these measures.

The engineering firm e7, which specializes in energy and environmental technology, was commissioned by the environmental protection organization to investigate the question: "How and when do thermal refurbishment and boiler replacement pay off?"

"It pays off even without federal funding"

 "Although no federal funding is currently available, the decision to thermally renovate and replace a boiler is already paying off. If you live in a poorly insulated building with gas heating and do not take any measures, you can expect additional costs of 85,000 to almost 130,000 euros over a longer period of time. Conversely, thermal refurbishment and a change in the heating system can not only save money in the long term, but also reduce the CO2 balance, increase living comfort and protect against price increases for gas and oil in the long term," says Johannes Wahlmüller, climate and energy spokesman for GLOBAL 2000, summarizing the advantages of thermal-energetic refurbishment.

Economically sensible investment in the long term

Study author Johanna Jicha takes the same line: "With this study, we were able to show that extensive renovations of single-family homes represent an economically sensible investment in the long term. The results not only show that replacing a fossil-fuel heating system saves energy costs, but also that thermal refurbishments bring significant financial benefits over the lifetime of buildings - in addition to an increase in comfort. The calculated payback periods for different variants give reason to hope that more owners will take the step to renovate their building."

Different variants of thermal refurbishment

The thermal refurbishment of a detached house heated with gas was investigated. Variants of a

• Comprehensive thermal refurbishment (insulation of facade, basement and roof, window replacement, boiler replacement)
• a partial refurbishment (insulation of the attic, replacement of windows, replacement of the heating system),
• a variant without heating replacement and
• a basic variant in which only essential investments and repairs are carried out.

A life cycle analysis was carried out over a period of 30 years. Existing residual values and state subsidies (one-off grants) were also taken into account, as was the fact that no federal funding is currently available.

Using sustainable solutions

Insulating the basement and roof plays a major role in thermal refurbishment. Facade insulation is also often considered, but this can also be very problematic. Styrofoam panels are often used for insulation, but these are of problematic origin.

The main raw material for polystyrene production is polystyrene resin, which is derived from crude oil. While polystyrene offers numerous advantages in terms of insulation, lightweight packaging and affordability, its environmental impact is problematic. The material is not biodegradable.

There are alternatives made from renewable, non-fossil raw materials, one of the great advantages of which is that they do NOT have to be disposed of as hazardous waste at the end of their service life. We have summarized alternatives to polystyrene in the following article.

Sustainable building: Building materials

Inaction is expensive

The results clearly show that over a period of 30 years, doing nothing is the most expensive:

• The basic variant, i.e. doing nothing, incurs the highest costs of around 284,000 euros over the life cycle of 30 years and therefore performs the worst.
• However, if a comprehensive thermal refurbishment is implemented and a heat pump is installed, you can save between around
  • EUR 129,000 (Tyrol),
  • 113,000 (Styria),
  • EUR 109,000 (Carinthia),
  • EUR 108,000 (Vienna),
  • EUR 108,000 (Salzburg),
  • EUR 104,000 (Vorarlberg),
  • EUR 94,000 (Upper Austria),
  • EUR 88,000 (Burgenland) and
  • EUR 85,000 (Lower Austria) in costs compared to the basic variant.

Residual values after 30 years of use are included in these figures. The range between the individual state subsidies is wide. In Tyrol, for example, the highest savings are achieved compared to no action, because the state subsidy there is the most attractive. In Burgenland, Lower Austria and Vorarlberg, the variant with pellet heating and partial refurbishment performs similarly well to the variant with comprehensive refurbishment and a heat pump.

HERE you can find the results of the different variants broken down by federal state.

High initial investment that is amortized at different rates

Nevertheless, thermal renovation and boiler replacement require high initial investments. Attractive subsidies are important so that households can make these investments. A subsidy rate of 35% of the investment costs is a prerequisite for reducing the amortization period to less than 10 years.

As no federal funding is currently available, the structure of the state funding is crucial. "It currently makes a big difference in which federal state you want to renovate. We need the political decision-makers at federal and state level to finally provide long-term, predictable and attractive subsidies so that households throughout Austria receive the necessary support for the high level of investment required," concludes Johannes Wahlmüller.