Hello everyone,
We are currently starting to deal with the technical aspects of our single-family home.
I haven’t found a thread discussing whether a ventilation system generally makes sense or not. So here is a general discussion thread on the topic:
At first, we looked into various timber frame construction providers, which made us quite sensitive in this area. Naturally, a ventilation system is quite important due to the tighter building envelope, which I can completely understand. However, everything is also marketed accordingly...
Since we have now decided to go with a regional solid construction company, completely different questions arise:
I currently have a detailed offer from a solid construction company:
- $10,000 additional cost for thermal insulation measures
- $13,000 additional cost for a central ventilation system or $9,000 additional cost for a decentralized ventilation system
--> So the repayment subsidy of $18,000 is of little use to me; on the contrary, I am even paying extra for this (of course, I get a “better” house in return).
Key Data:
- Single-family home city villa, 150m² (1,615 ft²) with basement
- Air-to-water heat pump
- Building material: brick
The questions I am now asking myself:
1. Is a ventilation system even necessary to achieve KfW 55 standard?
2. If yes, would it maybe make more sense to go for KfW 70 and forget about the subsidy?
3. Is a ventilation system really that great? There are many reports about noise, high maintenance, etc.
4. If yes, in our building project would a decentralized or central system be better? I have read a lot of positive things about decentralized systems, so central ones might not be an option? Is that correct or not?
5. Is it even possible to reach KfW 55 standard otherwise? Do you really have to ventilate every 2 hours? Are there any experiences?
6. Is the additional $10,000 cost for KfW 55 without a ventilation system justified? Are the prices for the ventilation systems justified?
I know this is an endless debate and there are clearly two opinions here. However, we find it really difficult to make a decision. Maybe a few discussions and information here will help us make up our minds.
We are currently starting to deal with the technical aspects of our single-family home.
I haven’t found a thread discussing whether a ventilation system generally makes sense or not. So here is a general discussion thread on the topic:
At first, we looked into various timber frame construction providers, which made us quite sensitive in this area. Naturally, a ventilation system is quite important due to the tighter building envelope, which I can completely understand. However, everything is also marketed accordingly...
Since we have now decided to go with a regional solid construction company, completely different questions arise:
I currently have a detailed offer from a solid construction company:
- $10,000 additional cost for thermal insulation measures
- $13,000 additional cost for a central ventilation system or $9,000 additional cost for a decentralized ventilation system
--> So the repayment subsidy of $18,000 is of little use to me; on the contrary, I am even paying extra for this (of course, I get a “better” house in return).
Key Data:
- Single-family home city villa, 150m² (1,615 ft²) with basement
- Air-to-water heat pump
- Building material: brick
The questions I am now asking myself:
1. Is a ventilation system even necessary to achieve KfW 55 standard?
2. If yes, would it maybe make more sense to go for KfW 70 and forget about the subsidy?
3. Is a ventilation system really that great? There are many reports about noise, high maintenance, etc.
4. If yes, in our building project would a decentralized or central system be better? I have read a lot of positive things about decentralized systems, so central ones might not be an option? Is that correct or not?
5. Is it even possible to reach KfW 55 standard otherwise? Do you really have to ventilate every 2 hours? Are there any experiences?
6. Is the additional $10,000 cost for KfW 55 without a ventilation system justified? Are the prices for the ventilation systems justified?
I know this is an endless debate and there are clearly two opinions here. However, we find it really difficult to make a decision. Maybe a few discussions and information here will help us make up our minds.
So how far along is your build? Depending on the general contractor / main contractor, I would say it’s still possible during the detailed planning stage.
In any case, I had already submitted my building permit / planning permission application and made changes afterward.
In any case, I had already submitted my building permit / planning permission application and made changes afterward.
P
pagoni20208 Apr 2021 20:34You could already have your current status checked with a KfW calculation. Maybe you have already met the requirements without realizing it 😀
It shouldn’t be too difficult depending on your current design.
Insulate the foundation slab, install different windows, possibly add more roof insulation, use controlled mechanical ventilation… just to name a few adjustment options.
It shouldn’t be too difficult depending on your current design.
Insulate the foundation slab, install different windows, possibly add more roof insulation, use controlled mechanical ventilation… just to name a few adjustment options.
Thank you for your response.
After reading all the posts, I feel like I’m suffocating in a KFW55 house without controlled ventilation. :-D
The building currently exists only on paper. If the general contractor starts causing problems or demands excessive prices, does the entire trade have to be removed?
What would be a “reasonable” price for a 125 m2 (1,345 sq ft) semi-detached house in the northern Ruhr area?
After reading all the posts, I feel like I’m suffocating in a KFW55 house without controlled ventilation. :-D
The building currently exists only on paper. If the general contractor starts causing problems or demands excessive prices, does the entire trade have to be removed?
What would be a “reasonable” price for a 125 m2 (1,345 sq ft) semi-detached house in the northern Ruhr area?
P
pagoni20208 Apr 2021 20:55Hardi88 schrieb:
After reading all the posts, I feel like I’ll suffocate in a KFW55 house without a mechanical ventilation system. :-D No, first there will be breathing masks coming out of the ceiling, don’t worry. You only hear about that occasionally.
Hardi88 schrieb:
If the general contractor starts causing trouble or demands excessive prices, does the entire trade have to be removed? Achieving a KFW standard is not a separate trade by itself. The individual materials add up to that, and the energy consultant can tell you WHAT you need to do to meet the requirements. Of course, it makes sense to implement measures that you would personally benefit from even without the KFW standard. I wouldn’t recommend just chasing after KFW incentives.
Hardi88 schrieb:
What would be a “reasonable” price for a 125 m2 (1345 sq ft) semi-detached house in the northern Ruhr area? For selling?
It depends on what has been planned so far and what you additionally can/should/want to do to meet the standard. Then the general contractor will tell you what the extra costs are, or whether and how it is possible. For us, it was completely straightforward, though sometimes I read about unpleasant experiences elsewhere, so you need to ask—especially the energy consultant!
Depending on the federal state, it also makes sense to contact consumer advice services; some even offer free and very good consultations by energy experts.
M
majuhenema8 Apr 2021 20:56Are you asking about the ventilation system itself, or is it meant to serve another purpose (KfW 55)?
You should ask the general contractor for that. 😉
You should first follow the advice mentioned above.
Stay calm. Friends who built with an architect two years ago using the same bricks consciously decided against mechanical ventilation and have no regrets.
Hardi88 schrieb:
Can I still negotiate?
You should ask the general contractor for that. 😉
Hardi88 schrieb:
The building currently exists only on paper. So if the general contractor complains or demands excessive prices, does the entire trade have to be removed?
You should first follow the advice mentioned above.
Hardi88 schrieb:
After all the posts, I have the feeling I’ll suffocate in a KfW 55 house without mechanical ventilation. :-D
Stay calm. Friends who built with an architect two years ago using the same bricks consciously decided against mechanical ventilation and have no regrets.
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