Table of Contents
If you do it, do it right!
Building components are repaired, renewed or retrofitted. In most cases, this is the correct approach to improve the thermal insulation of the building envelope. The effectiveness of these measures is proven, and the result has been documented in several publications [Bastian 2022].
Implementing thermal insulation correctly results in energy savings, especially in old buildings, where the resulting energy efficiency can be even higher than expected. [Bastian 2022].
Energy efficiency depends on a few principles: retrofitting measures can significantly improve a building's heating demand. The following articles explain this further.
The second crucial element in the energy transition is expanding the renewable energy supply. This expansion will need to be accomplished by energy suppliers, who have the power to replace fossil-fuel-based energy sources. Distributed energy sourcing can significantly contribute to an increased share of renewable energy sources in the grid, especially photovoltaics.
For example, renewable energy in Germany is dependent on wind energy and solar power generation. There are opportunities to broaden renewable energy generation, such as applying hydropower more widely. Biomass complicates the situation. We agree with the UBA evaluation that biomass combustion (apart from exceptional circumstances) doesn't provide a sustainable perspective. On the one hand, the active potential here is relatively low; on the other hand, the priorities of biomass are clear:
- The ecological balance contribution
- Food supply assurance
- Provision of renewable raw materials for a sustainable economy.
There is broad consensus that the remaining amount of biomass for energy consumption will be lower than what we use today. However, it's evident that burning biomass for heating is inefficient for raw material and generates polluting emissions. As such, we should avoid relying on this material. Expanding wind energy and photovoltaics is essential to achieving our energy transition and sustainability goals. There is no doubt that these energies also impact the environment; however, the effect is much smaller than fossil energy.
With the energy efficiency process, renewable energy can meet the overall energy demand and maintain the high-quality life we have become accustomed to in a sustainable system.
The cost of PV panels has decreased sharply, making them widely accessible. Roofs should be covered with PV whenever possible. However, covering the whole facade with PV is now an additional option. When new wall cladding is required, such as a curtain wall for thermal insulation, PV panels can act as a climate envelope. PV panels are usually less expensive than traditional cladding options. Furthermore, the PV provides an additional function - producing electricity and benefitting the local economy.
What about economy, cost and financing?
- Planning retrofit steps ahead of time benefits residential homes. Especially while low-interest rates are low and the energy crisis is ongoing, planning and implementing these measures is worth the upfront cost for long-term energy savings.
- A retrofit plan is necessary: a new energy-efficient window doesn't need replacing. Timing replacements and upgrades is essential for keeping additional investment costs in line with improved energy outcomes.
- In exceptional situations (e.g. the shortage of fossil fuel), thermal insulation measures are the most accessible measure, compared to many other approaches, the accessibility of which is limited. The know-how can be quickly gathered, especially by those already working in the construction sector.
- Economy: A few days of retrofitting to install adequate insulation saves years of energy costs. There are days or weeks in winter each year when certain renewable energy sources are limited, and energy demand is higher for heating. This will become more expensive for everyone. The correct implementation of these measures also significantly improves the durability and comfort of the building. [Feist 2016].
[Bastian 2022] Bastian, Z. et al:Retrofit with Passive House Components; Energy Efficiency, 2022
[Feist 2016] Feist, W. et al: 25 Jahre Passivhaus Darmstadt Kranichstein (vollständiger Bericht in deutscher Sprache) sowie Peer-reviewed paper on "Durability of building fabric components and ventilation systems in passive houses"