Hello everyone,
We have a house from the 1980s that we want to renovate extensively. For this, we consulted an energy advisor to get expert advice. In the end, his analysis showed that we should reroof the house, insulate the facade with an external thermal insulation composite system (ETICS / external wall insulation), insulate the basement, and replace the windows. Additionally, a ventilation system should be installed, and the heating system converted to a heat pump.
That all sounded great, of course...
Until a few days ago, when we saw a report on NDR stating that ETICS can be highly flammable, ventilation systems can become contaminated with germs and bacteria relatively quickly, and that costs—such as filter replacements—are so high that an extensive renovation might not be worthwhile. We were quite shocked, especially because of the health concerns related to germs, and now we are unsure whether to proceed with any of these measures at all.
We hope that there might be some knowledgeable and experienced people here who can recommend which path we should take.
Thank you very much for any advice, tips, or questions!
We have a house from the 1980s that we want to renovate extensively. For this, we consulted an energy advisor to get expert advice. In the end, his analysis showed that we should reroof the house, insulate the facade with an external thermal insulation composite system (ETICS / external wall insulation), insulate the basement, and replace the windows. Additionally, a ventilation system should be installed, and the heating system converted to a heat pump.
That all sounded great, of course...
Until a few days ago, when we saw a report on NDR stating that ETICS can be highly flammable, ventilation systems can become contaminated with germs and bacteria relatively quickly, and that costs—such as filter replacements—are so high that an extensive renovation might not be worthwhile. We were quite shocked, especially because of the health concerns related to germs, and now we are unsure whether to proceed with any of these measures at all.
We hope that there might be some knowledgeable and experienced people here who can recommend which path we should take.
Thank you very much for any advice, tips, or questions!
M
Micha&Dany29 Nov 2012 07:10Hello Schwebbs,
I would suggest reconsidering the renovation. Or better yet, consult another "expert." What qualifications does your "energy consultant" have? Nowadays, unfortunately, anyone who has attended a weekend course can call themselves an energy consultant...
I had a similar case nearby (a house from the 1960s): An energy consultant recommended external wall insulation and a new heating system. He said it would pay off after 15 years. A simple check of this calculation (cost of insulation divided by current heating costs) showed a payback period of 40 years. But that would mean having no heating costs for 40 years at all, and the loan interest for the investment wasn’t even considered... Well, there was no need to calculate further in this case.
Regarding the external thermal insulation composite system (ETICS), everyone can have their own opinion... I’m currently experiencing it in a rented apartment... It feels like living in a plastic bag... And about fire safety... Well, everyone should know how easily polystyrene can burn...
As for ventilation systems, I’d be happy to share my experience with you in a few months. I’m certainly looking forward to having one soon. And concerning germs—strictly speaking, you’d then also have to give up your kitchen and bathroom! The number of germs that can form if you don’t clean properly is astonishing! Of course, you have to clean the system regularly and keep the filters clean or replace them. But you also need to clean your oven regularly, your bathroom, and so on...
But this is just my personal opinion.
Best regards,
Micha 😎
I would suggest reconsidering the renovation. Or better yet, consult another "expert." What qualifications does your "energy consultant" have? Nowadays, unfortunately, anyone who has attended a weekend course can call themselves an energy consultant...
I had a similar case nearby (a house from the 1960s): An energy consultant recommended external wall insulation and a new heating system. He said it would pay off after 15 years. A simple check of this calculation (cost of insulation divided by current heating costs) showed a payback period of 40 years. But that would mean having no heating costs for 40 years at all, and the loan interest for the investment wasn’t even considered... Well, there was no need to calculate further in this case.
Regarding the external thermal insulation composite system (ETICS), everyone can have their own opinion... I’m currently experiencing it in a rented apartment... It feels like living in a plastic bag... And about fire safety... Well, everyone should know how easily polystyrene can burn...
As for ventilation systems, I’d be happy to share my experience with you in a few months. I’m certainly looking forward to having one soon. And concerning germs—strictly speaking, you’d then also have to give up your kitchen and bathroom! The number of germs that can form if you don’t clean properly is astonishing! Of course, you have to clean the system regularly and keep the filters clean or replace them. But you also need to clean your oven regularly, your bathroom, and so on...
But this is just my personal opinion.
Best regards,
Micha 😎
Hello,
Overall, one should carefully consider such an extensive “all-round overhaul” and possibly focus more on critical priority areas.
Given the current energy prices, it makes little sense to plan on them remaining stable; a progressively rising trend should be taken into account.
Moreover, there is probably no better and safer investment today than investing in your own building!
Best regards
Schwebbs schrieb:In that case, a new build might almost make more sense. ;-) This energy consultant (EC) is certainly not a mechanical and electrical (M&E) planner, and economic efficiency for the owner apparently isn’t a priority here.
....In the end, his analysis concluded that we should redo the roof, insulate the facade with an external thermal insulation composite system (ETICS / external wall insulation), insulate the basement, and replace the windows. Additionally, a ventilation system should be installed and the heating technology switched to a heat pump.
That all sounded great, of course...
Schwebbs schrieb:There are other insulation materials available! ;-)
...Until a few days ago when we saw a report on NDR stating that ETICS can be highly flammable,...
Schwebbs schrieb:Aside from the alleged “germs,” retrofitting a centralized balanced ventilation system with heat recovery into an existing building is already quite demanding and expensive, depending on the existing building structure!
...the ventilation systems are already full of germs and bacteria after a relatively short time, and that costs for, for example, filter replacements are so high that extensive renovations are not economically viable.
Overall, one should carefully consider such an extensive “all-round overhaul” and possibly focus more on critical priority areas.
Given the current energy prices, it makes little sense to plan on them remaining stable; a progressively rising trend should be taken into account.
Moreover, there is probably no better and safer investment today than investing in your own building!
Schwebbs schrieb:I would doubt that just a few kind people would be truly and sustainably helpful here. Only a well-trained expert will likely be able to provide assistance. Relying on a few keystrokes in some energy consulting software probably won’t get you far, as this example clearly shows.
...We hope that there might be some kind people here (especially those knowledgeable and experienced in this field) who can recommend which path we should take.
Best regards
K
K.Brodbeck29 Nov 2012 09:06Schwebbs schrieb:
Hello everyone,
we have a house from the 1980s that we want to renovate extensively. We consulted an energy advisor to get expert advice. Ultimately, his analysis concluded that we should redo the roof, insulate the facade with an external insulation composite system (ETICS / EIFS), insulate the basement, and replace the windows. Additionally, a ventilation system should be installed, and the heating system converted to a heat pump.
That all sounded great, of course...
Until a few days ago, when we saw a report on NDR stating that ETICS can be highly flammable, ventilation systems quickly become full of germs and bacteria, and the costs for filter replacements are so high that extensive renovations aren’t worthwhile. We were particularly shocked by the germs issue and now don’t really know what or whether we should proceed with anything at all...
We hope there might be some kind and knowledgeable people here, especially those with experience in this area, who can recommend which direction we should take.
Thank you very much for all your advice, tips, or even questions!!!Hello Schwebbs,
Energy advisors with 'official' training usually base their advice strictly on what they have learned. That means insulation is great—preferably external with ETICS/EIFS, new windows, roof insulation, and so on—often without much common sense ;-).
I believe that an independent advisor (who, unfortunately, usually has no government funding) is often a better choice than those who have only completed a weekend course. But back to your question.
It’s difficult to give a solid recommendation without seeing the building. Houses from the 1980s often have a good structure you can build upon.
If your goal is an energy-efficient house, then all those measures should indeed be carried out. If your aim is to optimize the existing structure, there are alternative approaches.
I come from an ecological perspective, so my suggestions may differ from your energy advisor’s.
If the roof is not yet insulated, I would recommend insulating it—but only if the attic is or will be used. Otherwise, insulating the ceiling of the top floor is reasonable and sufficient. When insulating the roof, pay attention to summer heat protection. For example, mineral wool is good in winter to keep heat in, but it lets heat through in summer.
A second important point is the floor above an unheated cellar or soil.
Thirdly, consider the facade and the windows. How old are the windows? Does it make sense to replace or adapt them? Should the facade be insulated or not (depending on wall thickness, this may not be cost-effective). There are also ETICS/EIFS systems designed to meet fire safety requirements.
The fourth point is the ventilation system. Is it desired? There are several types: centralized and decentralized ventilation. For renovations, decentralized systems usually fit better, while centralized ventilation is generally better—but only if it can be managed optimally. Then issues with contamination and bacterial growth become less problematic.
The fifth point is heating. For me, the question is what you want. Should it operate fully automatically, or do you prefer heating with wood logs, for example? Should there be solar support, or do you want a heat pump? I understand not wanting to install gas or oil heating anymore. Heat pumps are excellent devices, especially those using outdoor air—though I consider these only really suitable for very well-insulated (passive or better) houses.
That’s enough for now!
Best regards
K.Brodbeck
Hello,
I wouldn’t let a single report unsettle you, as unfortunately these can vary widely in both directions…
The suggestions listed are really the typical measures: insulating the largest exterior surfaces (basement ceiling, exterior walls, roof surface), upgrading the windows by replacement, and then considering replacing the heating system.
Regarding the improvement measures, it should definitely be said that the consultant should not only present all the possible measures but also analyze the economic side for you, showing what each measure achieves and how much can be saved.
The same applies to heating: for new builds, a ventilation system with heat recovery and a geothermal heat pump can certainly be very interesting if planned together with the building. For existing buildings, especially if a gas connection is already available, it may make more sense and be more cost-effective to install a gas condensing boiler.
So again, ask your consultant for clarification and request several different options or proposals from them.
As mentioned before, advice without an on-site inspection is difficult, but energy consumption (gas, oil, wood) per year, building size, insulation standard, and type of heating system are essential information for further assessments.
I wouldn’t let a single report unsettle you, as unfortunately these can vary widely in both directions…
The suggestions listed are really the typical measures: insulating the largest exterior surfaces (basement ceiling, exterior walls, roof surface), upgrading the windows by replacement, and then considering replacing the heating system.
Regarding the improvement measures, it should definitely be said that the consultant should not only present all the possible measures but also analyze the economic side for you, showing what each measure achieves and how much can be saved.
The same applies to heating: for new builds, a ventilation system with heat recovery and a geothermal heat pump can certainly be very interesting if planned together with the building. For existing buildings, especially if a gas connection is already available, it may make more sense and be more cost-effective to install a gas condensing boiler.
So again, ask your consultant for clarification and request several different options or proposals from them.
As mentioned before, advice without an on-site inspection is difficult, but energy consumption (gas, oil, wood) per year, building size, insulation standard, and type of heating system are essential information for further assessments.
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