ᐅ Insulating a wood-based floor slab with straw

Thank you for your response!
I am patient, and the building project is planned within the next 5 years.

To clarify any confusion you might have:
I want to build sustainably, but that doesn’t mean I am willing to accept things like insects inside my home.
To make sustainable building accessible to the general public, we need solutions that are less off-putting (such as insects in the house).
I am convinced that such solutions exist! And natural materials can also contribute positively through appropriate structural measures.

The mentioned structural engineering aspect is a good point.
I believe a single-family house with 1.5 full stories and a pitched roof is definitely possible in this context.

Best regards

landhausbauer schrieb:

Thank you for the response!
I am patient, and the construction timeline is within the next 5 years.

To clarify your surprise a bit:
I want to build sustainably, but that does not mean I want to accept things like insects inside my house.
To make sustainable building accessible to the general public, solutions are needed that are less off-putting (such as insects in the house).
And I am convinced that such solutions exist! Natural building materials can also contribute through appropriate structural measures.

The mentioned structural engineering is a good point.
I assume that a single-family house with one and a half full floors and a pitched roof is basically not excluded here.

Best regards

I understand you, but I am just aware of the frequently used term "sustainability." Of course, no one wants lots of insects in the house, but proximity to nature, natural building materials, and fewer interventions in nature inevitably bring such things sometimes. Furthermore, the question arises whether building new is sustainable in general.
A friend lives in Scandinavia in a dream location by a lake with lots of glass, views, nature, etc., yet he constantly struggles with animals on and under the house (he has a construction style like the one you mentioned). Because he leaves the site mostly natural, quite some wildlife lives there, which is sustainable and beautiful in itself. He wants the direct nature...but how he would like it...and then it is no longer THE nature.
I believe the "mass-market sustainable building" you mentioned will be difficult because these aspects partly exclude each other. When you build, you should realize that it will inherently cause a significant impact on the local environment, no matter what you put there. Once the excavator starts working, sustainability is over. It is somewhat like Gerhard Polt describes, when a lacquer factory was allowed to build in a nature reserve and had to plant wild vines along the fence as an ecological measure.
Generally, I dislike the distinction (not from you!) that some build ecologically sustainable, and others are called the "pigs" in this regard.
I am aware that with my planned build I will cause damage to nature and that, ecologically, it is nonsense to live on 150 sqm (1600 sq ft) or more; however, I am doing it anyway.
But basically, I understand your point that new solutions are always needed, and we must try to leave as little mess as possible if we really want to build. In my opinion, this is achieved mostly through restraint, minimalism, and discipline.

Building as small as possible is the key to sustainability. It doesn’t have to be a tiny house, but also not over 150 sqm (1,615 sq ft). Renovation or building in a gap within existing development.

Use solid wood, but pay attention to where it comes from. Ordering locally doesn’t always mean it actually comes from nearby. Some of our walls were partly from Lithuania, partly from Austria, and only the ridge beam came from the Spessart region. Whether it actually grew there, we have no idea.

Similar situation with construction straw. It isn’t processed or pressed differently than regular straw, so it’s only produced on large fields that we don’t fully have in Germany.

You will probably get the most useful information by trying to find and directly contact builders who use straw. It’s not an off-the-shelf building material.

I am not a professional either, but I have faced such questions throughout my life and can understand the conflict well.
Keeping the house “as free of toxins as possible” seems like a wise approach.
A key issue can be: “What is actually toxic and what is harmless?” There are quite different opinions on this.
And:
Not being afraid of mice and insects doesn’t mean you have to invite them into the house.
I also don’t think it’s unreasonable to research the possible disadvantages of natural materials.

Straw is certainly not simply “laid under the floor,” but processed in some way. Pressed, mixed with binders, or something like that?

What I’ve found out is that wood fiberboards are currently very popular because they have so many good qualities and come in many varieties for different purposes.

They will be used in my house soon (for the attic, not under the floor but under the ceiling).

There is a “straw house” not far from here. I have watched the construction sometimes and found it quite “appealing.”
Straw definitely works as a building material (however, the walls were at least half a meter (20 inches) thick).

Thanks for your thoughts!
A true straw bale house (of which there are already examples) is not really for me; I just can’t get comfortable with the idea.
Also, because solid wood walls really convince me in every aspect (well, maybe not in terms of cost).

Wood fiber insulation is definitely interesting! But compared to straw bales, it is clearly more expensive.
And for the slab foundation (no basement) and the roof, very thick insulation layers simply don’t bother me..

What is the plan?
Will the straw simply be "filled in," or are there any preparatory steps involved?

Filling it in untreated feels too risky to me (just a gut feeling).
I believe it requires some kind of fire protection and compaction.