Yeah, at the core it suggests each person lends €1600 (~$1850 USD) distributed in an unofficial and impromptu way, hoping to get it all back as a home-improvement good. That has some implications like:

1. You have ~15 friends and you all have houses.

2. All of you can confidently allocate €1600 this year towards one major component of the upgrade, and believe you will benefit from it in the next ~15 years.

3. All the friends make enough money that they're confident anything going wrong with €1600 loans/debts won't cause pain or problems in the friendship.

How rich do you need to be for the mentality of that last one? AFAICT that's ~3% of yearly salary (pre-tax) in Germany.

Personally, I do not want my friend group to be tangled up in a financing scheme, and if I wanted a financing scheme I wouldn't do something half-assed that could explode into acrimony if anyone chooses (or is forced by circumstance) to exit having contributed without receiving or vice-versa.

I could understand friends having good-years helping out ones having bad-years ("banqueting" [0]) but what's being proposed really doesn't map to that.

[0] https://acoup.blog/2020/07/24/collections-bread-how-did-they...