From when does the financing start at the handover of the house in summer 2017?

I stick to my opinion, the complete package has to be right

That is correct, but if as a customer I need 12 or even 18 months of availability (and that is clear from the start!!!), then it is simply not the right product.

And at today's interest rate level, it is shocking. The bank earns more from holding the availability than during the actual loan term.

Therefore, fixed dates known from the outset should always be taken into account.

In IT, that's just one more number or date. We both know that ourselves.

If 18 months are important, of course that should be emphasized. However, it also makes no sense to strike a large number of providers off the list in a market with standardized products due to exotic wishes. The programs the intermediaries use are a good indicator of that. If 20 providers are "green" at 12 months, but only two at 18, I would question my requirement. Because in the end, the complete package counts, so 6 months of standby interest can actually be better.