I don't know why the OP opens this thread just now, because according to the website:
https://zerorealestate.ch/de/"Dear guests
Due to the current situation and lack of resources, the Zero Real Estate project cannot take place this year. We look forward to welcoming you next year - where the only star is you.
Your Zero Real Estate Team"I mean, it's funny, but right now they don't offer their services.
.
So this mean that 2021 is not their year? and will resume in 2022?
Well the motive of OP here is to Hear the opinion of people about this, if they are willing to stay or not, meaning this looks like a Poll?