ᐅ Which House Concept? Fundamental Questions for Building a Home
Created on: 20 Sep 2019 11:53
L
Luftpumpe
Hello everyone,
We are fortunate to own a building plot and are now facing the difficult choice of how to proceed. For several months, we have been researching, visiting model homes, and actively reading forums. When it comes to layouts and features, opinions vary greatly, and depending on budget and taste, the possibilities seem endless.
But when it comes to the fundamental question of how to build today in an affordable, efficient, and above all healthy way, there should at least be a rough consensus! From everything we have read so far, we would probably prefer to build a Thoma house (36cm (14 inches) Holz100 walls), but financially that probably won’t be possible.
When we look for alternatives, we are often told that KFW40 (KFW40 / Passive House standards) is not achievable, that breathable construction is impossible, and that a mechanical ventilation with heat recovery system is absolutely necessary. Then, you keep searching and come across more “alternative” options like LowTec Bio Solar houses, which seems a bit too extreme for us.
We want to build a house free of harmful substances, and avoiding various materials is the best way to be sure that in a few years, nothing new will be found to be problematic. In this sense, a pure timber house does make some sense.
Then, the advice is that solar thermal systems are not worth it, so photovoltaic systems on the roof should be used instead. To make good use of that, a heat pump is necessary, and then air-to-air heat pumps are offered because geothermal with underfloor heating is so much more expensive. So, it’s either robbing a bank or making compromises.
And that’s exactly the kind of compromises we are looking for now. Who has chosen a particular building concept and for what reasons? Is a vapor barrier really necessary in the building envelope? Which heating and insulation technologies are still cost-effective today? And how do I create the healthiest possible indoor climate?
Thank you & best regards,
Luftpumpe
We are fortunate to own a building plot and are now facing the difficult choice of how to proceed. For several months, we have been researching, visiting model homes, and actively reading forums. When it comes to layouts and features, opinions vary greatly, and depending on budget and taste, the possibilities seem endless.
But when it comes to the fundamental question of how to build today in an affordable, efficient, and above all healthy way, there should at least be a rough consensus! From everything we have read so far, we would probably prefer to build a Thoma house (36cm (14 inches) Holz100 walls), but financially that probably won’t be possible.
When we look for alternatives, we are often told that KFW40 (KFW40 / Passive House standards) is not achievable, that breathable construction is impossible, and that a mechanical ventilation with heat recovery system is absolutely necessary. Then, you keep searching and come across more “alternative” options like LowTec Bio Solar houses, which seems a bit too extreme for us.
We want to build a house free of harmful substances, and avoiding various materials is the best way to be sure that in a few years, nothing new will be found to be problematic. In this sense, a pure timber house does make some sense.
Then, the advice is that solar thermal systems are not worth it, so photovoltaic systems on the roof should be used instead. To make good use of that, a heat pump is necessary, and then air-to-air heat pumps are offered because geothermal with underfloor heating is so much more expensive. So, it’s either robbing a bank or making compromises.
And that’s exactly the kind of compromises we are looking for now. Who has chosen a particular building concept and for what reasons? Is a vapor barrier really necessary in the building envelope? Which heating and insulation technologies are still cost-effective today? And how do I create the healthiest possible indoor climate?
Thank you & best regards,
Luftpumpe
Sorry, I still can't send a private message. However, it wouldn’t help you anyway: since we have different conditions, the offer wouldn’t be useful to you either. As a note: based on some of the prices mentioned here, this is a provider with normal to low pricing. But we are not planning a mansion, so it’s hard to assess.
@Luftpumpe
It wasn’t about eco-friendliness or wood cut during a full moon at midday. But what’s the point of designing and paying for a healthy living environment if the new built-in wardrobe ruins it all?
Passive houses have a heating system. From air-to-air heat pumps to standard air-to-water heat pumps with underfloor heating.
It wasn’t about eco-friendliness or wood cut during a full moon at midday. But what’s the point of designing and paying for a healthy living environment if the new built-in wardrobe ruins it all?
Passive houses have a heating system. From air-to-air heat pumps to standard air-to-water heat pumps with underfloor heating.
L
Luftpumpe20 Sep 2019 13:41@Lenschke: May I ask where you are building? Could you also provide some details about whether there is a basement, the type of heating, and the KFW standard? Thanks!
The idea behind moon timber is that it is cut in winter when the sap in the wood is dormant, and the moon influences the wood similarly to tides by pressing the sap into the wood during ebb tide... and yes, you shouldn’t fill the rooms with IKEA furniture right away. But again, it also depends on the quantity, and significantly reducing potential sources of pollutants is the foundation. The PVC insulation on the cables inside the walls then doesn’t matter.
Quote from Wikipedia:
“A passive house is a building that, due to its high level of thermal insulation and the principle of significantly reducing ventilation heat losses through a heat exchanger, generally does not require a conventional water-based heating system.”
It is clear that you can install a (water-based) heating system in a passive house, but whether that is sensible or aligns with the original concept of the passive house is a different matter.
Still, there are expensive long-term solutions that are not that good and cheaper solutions that are better. That is exactly what I am focusing on now—a coherent overall concept. There are also good examples of buildings without mechanical ventilation and without heating that are still warm enough in winter. Excellent insulation, large window areas, and the right location make this possible with perfect planning.
I just don’t want to back the wrong horse, like the people who once relied on night storage heaters.
The building should last at least one more generation with proper maintenance and cause as few follow-up costs as possible. And in terms of ongoing expenses, it should be as “affordable” as possible. Whether electricity will remain affordable over the next ten to twenty years or whether we will be flooded with cheap gas from Russia is anyone’s guess. But currently, renewables are being expanded, and I hardly believe that a fusion power plant will be up and running in Germany within five years.
The idea behind moon timber is that it is cut in winter when the sap in the wood is dormant, and the moon influences the wood similarly to tides by pressing the sap into the wood during ebb tide... and yes, you shouldn’t fill the rooms with IKEA furniture right away. But again, it also depends on the quantity, and significantly reducing potential sources of pollutants is the foundation. The PVC insulation on the cables inside the walls then doesn’t matter.
Quote from Wikipedia:
“A passive house is a building that, due to its high level of thermal insulation and the principle of significantly reducing ventilation heat losses through a heat exchanger, generally does not require a conventional water-based heating system.”
It is clear that you can install a (water-based) heating system in a passive house, but whether that is sensible or aligns with the original concept of the passive house is a different matter.
haydee schrieb:We completely agree on that! And you get what you pay for, and if you want the best, you have to dig deep into your pockets.
Much of it is marketing. You have to remember, every seller has the best and only wants your best (money)
Still, there are expensive long-term solutions that are not that good and cheaper solutions that are better. That is exactly what I am focusing on now—a coherent overall concept. There are also good examples of buildings without mechanical ventilation and without heating that are still warm enough in winter. Excellent insulation, large window areas, and the right location make this possible with perfect planning.
I just don’t want to back the wrong horse, like the people who once relied on night storage heaters.
The building should last at least one more generation with proper maintenance and cause as few follow-up costs as possible. And in terms of ongoing expenses, it should be as “affordable” as possible. Whether electricity will remain affordable over the next ten to twenty years or whether we will be flooded with cheap gas from Russia is anyone’s guess. But currently, renewables are being expanded, and I hardly believe that a fusion power plant will be up and running in Germany within five years.
With the room plan, you won’t really get below 160 sqm (1,722 sq ft).
You can save money by
- having a simple floor plan
- choosing a flat plot of land
- focusing on one main priority
- finding a builder who shares that priority
(let’s just say healthy living. Reading labels and selecting materials can probably be done by anyone, but it costs money. If you have a builder who actually practices and lives by this, they won’t offer you anything that doesn’t meet those standards. They don’t need to look for alternatives. Everything is taken care of this way, and they might even pay the same price for a different color as for one without the healthy living certification)
- looking for a detailed scope of work that best matches your preferences
(upgrading from a handheld shower to a built-in rain shower can be very expensive; downgrading from a built-in rain shower to a handheld shower will at best get you a credit equal to the product’s value)
We built a passive house, solid wood construction, healthy living (I didn’t even know that existed) ready to move in by 2017. The price was not that high. For that, a house built to the energy saving regulation standard by the same provider (if they had built it) wouldn’t have cost much less. The slope of the land was and still is the main cost driver.
You can save money by
- having a simple floor plan
- choosing a flat plot of land
- focusing on one main priority
- finding a builder who shares that priority
(let’s just say healthy living. Reading labels and selecting materials can probably be done by anyone, but it costs money. If you have a builder who actually practices and lives by this, they won’t offer you anything that doesn’t meet those standards. They don’t need to look for alternatives. Everything is taken care of this way, and they might even pay the same price for a different color as for one without the healthy living certification)
- looking for a detailed scope of work that best matches your preferences
(upgrading from a handheld shower to a built-in rain shower can be very expensive; downgrading from a built-in rain shower to a handheld shower will at best get you a credit equal to the product’s value)
We built a passive house, solid wood construction, healthy living (I didn’t even know that existed) ready to move in by 2017. The price was not that high. For that, a house built to the energy saving regulation standard by the same provider (if they had built it) wouldn’t have cost much less. The slope of the land was and still is the main cost driver.
L
Luftpumpe20 Sep 2019 14:07haydee schrieb:
You can save money by
- simple floor plan CHECK
- flat plot CHECK What is a scope of work specification?
haydee schrieb:
We built a ready-to-move-in passive house in 2017, made of solid wood, healthy living standards (I didn’t even know that was a thing). The price wasn’t that high. For that price, a house built to energy-saving regulation standards by the same provider (if they had built one) wouldn’t have cost much less. The That sounds good! I’ll take that too
Yes, you really just have to find the right builder and separate the wheat from the chaff. As I said, we don’t have high demands for the bathroom. We live in an old building and have been showering for ten years in a bathtub with a handheld shower behind a shower curtain. A simple shower cabin will be enough, and a luxurious rain shower also requires a correspondingly powerful hot water system. If I need a wellness temple, I’ll go to a thermal spa, not the bathroom.
Yesterday I had a conversation with a prefab home builder... Me: There are also passive houses... Him: Yes, but we don’t offer those. There are also self-builders who moved out of their passive houses after a few years and built a “normal” house again. Me: Thanks for the chat...
So, you (or you all) are fully satisfied with your passive house? Are the annual heating costs roughly within the predicted range? I mean, if the price is similar, or the extra cost is low, it has to be worth it, right? Although they always say the last few kilowatt-hours saved are the most expensive.
An exterior insulation system (ETICS) made of EPS is also vapor-permeable, simply because it is not 100% vapor-tight. Marketing hype.
If indoor air is humid and condensation forms on the wall, no amount of vapor-permeable building materials will help move the moisture outside. That is simply nonsense. The amount of moisture that a vapor-permeable wall can transport outward is so insignificant compared to, for example, any form of ventilation, that one has to wonder why this is even used for marketing. This supposed material property has no meaningful impact on indoor climate. The homeopathy of the construction industry.
If indoor air is humid and condensation forms on the wall, no amount of vapor-permeable building materials will help move the moisture outside. That is simply nonsense. The amount of moisture that a vapor-permeable wall can transport outward is so insignificant compared to, for example, any form of ventilation, that one has to wonder why this is even used for marketing. This supposed material property has no meaningful impact on indoor climate. The homeopathy of the construction industry.
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