Mini, Eco-tec bottle, Earthship, Hill, Passive, Greenhouse?

Dry soil has a thermal conductivity of 0.15 to 0.30. Pet is at 0.24 and air 0.024. In comparison, concrete has 2.1 or aerated concrete (gas concrete) 0.08 to 0.25. Mineral wool with 0.032 to 0.050 or aerogel mats with 0.013 to 0.020 are of course better. But also much, much more expensive. The costs of the [Aearogel Matten] for example are only recovered after 32 or more years. Additionally, one could dispense with load-bearing capacity by leaving out the soil and filling the PET bottles only with air, thus achieving an extremely good insulation.

Unfortunately, 10,000 PET bottles have a deposit of €2000. However, 10,000 preform bottles at the China wholesaler also cost €500 + costs for a 30bar compressor and energy. So the €2000 is manageable. Now I just have to find out how long the PET bottles really last; they should last at least 50 to 100 years to be worthwhile.

For the sake of the environment, it is better not to use PET bottles. Even if they last 300+ years. When they decompose, all the toxic nonsense comes out. I think it is better if I wait for the CO2 plastic made from polypropylene carbonate + polyhydroxybutyrate. That should have better properties and is good for the environment.

I have to wonder why not all houses are built from plastic bottles, since they are such a miracle material. With that, the Berlin airport, the Elbphilharmonie, all new skyscrapers, football stadiums, ... could be had at a bargain price.

Well, the things also have to be filled and compacted, the time effort is priceless. It only pays off if you do it yourself or as a group without payment. Besides, they also have to be collected. If everyone builds with them, there won't be enough of them. I also think it's better to use PP bottles, because then it's not so bad if they stay in the concrete. If the PETs dissolve at some point, you get contaminated concrete.

In case anyone is still interested: I have completely moved away from plastic bottles by now. It’s not worth it (Pfand), contaminates the concrete (beton Recycling), and reduces its lifespan / can cause cracks in the concrete. Nowadays, I tend toward hempcrete (hempcrete) (above ground) and standard concrete (underground) produced with alternative energy. Then "mushroom insulation" (mushroom insulation) as thermal insulation.