House construction and sale - current residential property

Variant b would now be our way. Since we want to use the money for the house construction. The problem now is that the broker of the plot has not yet given a clear statement. We can only commit to the interested parties once we have found a plot. Otherwise, it could take forever.

we are at an advantage: we already have a plot and are currently planning the house. Variant b) has to be borne by the buyer. He has financing costs but no consideration. So you have to offer him something... for example pay rent. If you then no longer have to make any repayments yourself, then it can work out.