Hello everyone,
we recently purchased an older building (built around 1920) that has already been partially renovated. The previous owner had an energy consultant prepare an energy assessment report with a renovation roadmap. One important and, in our opinion, cost-effective measure is replacing the windows. Over the years, some of the windows have been updated, so they are all at different levels of condition, but they are still quite old (between 15 and 30 years). We have started researching the topic and have already had a glazier come to provide a quote. The more we learn about it, the more questions come up. Maybe someone here in the forum has experience and can help answer some of the most important ones.
Thank you in advance for your answers. If further information and/or pictures are needed, I can provide them gladly.
Best regards
we recently purchased an older building (built around 1920) that has already been partially renovated. The previous owner had an energy consultant prepare an energy assessment report with a renovation roadmap. One important and, in our opinion, cost-effective measure is replacing the windows. Over the years, some of the windows have been updated, so they are all at different levels of condition, but they are still quite old (between 15 and 30 years). We have started researching the topic and have already had a glazier come to provide a quote. The more we learn about it, the more questions come up. Maybe someone here in the forum has experience and can help answer some of the most important ones.
- According to the renovation roadmap, the exterior walls have a U-value of 0.265 and the roof 0.128. From our research, triple-glazed windows seem possible (and advisable?). What are the experiences regarding mold? Does it develop much faster now, or can it be managed without issues with sufficient ventilation?
- The house used to be divided into three small apartments and a stairwell that is not heated. The stairwell still has some very old windows (wooden frames, uninsulated). From an energy and cost perspective, does it make sense to replace these as well? The previous owner replaced almost all the windows, except for these. Could there be a technical building reason for this? As far as we can tell, not all areas in the stairwell are insulated (e.g., the exterior wall under the stairs).
- Is there anything else we should pay attention to?
Thank you in advance for your answers. If further information and/or pictures are needed, I can provide them gladly.
Best regards
I thank everyone for their answers, tips, and the time they have invested. I now have a clearer idea of how to proceed with the stairwell. I believe the previous owner, instead of addressing ventilation/heating issues, simply left some of the windows very old to avoid mold problems. As a result, it will probably be triple-glazed windows throughout, and I will additionally take care of mold prevention in the stairwell.
Even though I did not really want to discuss the ISFP, I will try to respond and explain why we are ignoring it. The house is already well modernized (except for the windows), and the ISFP aims at maximum optimization. Therefore, we do not need such a plan at all at this point, as we neither need nor want to renovate right now. All measures proposed in the ISFP (except window replacement) will probably only become necessary or relevant in at least 15 years.
Measure 1: Overlay insulation on rafters -> Roof including interior finishes is about 5 years old = economically not sensible, possibly only if the roof needs to be replaced anyway
Measure 2: Window/door replacement
Measure 3: Heat pump / photovoltaic system -> Heating system (including piping) was replaced 8 years ago = economically not sensible, possibly only if the heating system fails; photovoltaic system was planned anyway
Measure 4: Exterior insulation -> The house has 5-year-old interior insulation; the facade was renewed about 15 years ago and repainted 5 years ago = economically not sensible, possibly only when the facade needs to be renewed again.
Others may see this differently, but none of these measures are currently sensible enough to pay off even partly in my lifetime. By the time any of these measures become relevant, technological options may well be different and need to be reassessed.
11ant schrieb:
But underestimating it is the wrong conclusion
Even though I did not really want to discuss the ISFP, I will try to respond and explain why we are ignoring it. The house is already well modernized (except for the windows), and the ISFP aims at maximum optimization. Therefore, we do not need such a plan at all at this point, as we neither need nor want to renovate right now. All measures proposed in the ISFP (except window replacement) will probably only become necessary or relevant in at least 15 years.
Measure 1: Overlay insulation on rafters -> Roof including interior finishes is about 5 years old = economically not sensible, possibly only if the roof needs to be replaced anyway
Measure 2: Window/door replacement
Measure 3: Heat pump / photovoltaic system -> Heating system (including piping) was replaced 8 years ago = economically not sensible, possibly only if the heating system fails; photovoltaic system was planned anyway
Measure 4: Exterior insulation -> The house has 5-year-old interior insulation; the facade was renewed about 15 years ago and repainted 5 years ago = economically not sensible, possibly only when the facade needs to be renewed again.
Others may see this differently, but none of these measures are currently sensible enough to pay off even partly in my lifetime. By the time any of these measures become relevant, technological options may well be different and need to be reassessed.
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