So for me, part was the purchase price, part for the subsequent construction work. It was agreed that repayment would begin after full disbursement. Interest was due on amounts already drawn. So there was indeed a "double burden"; between the purchase price payment and the move, there were eight months during which I paid interest on an ever-growing amount. In fact, it worked out so that repayment only started after the move because only then was all the money drawn. I didn’t even negotiate this point; it was like that from the bank’s side. There was a "de minimis threshold"; if it was not met, the remaining amount was paid out. I assume this was so that you don’t leave €500 standing and thus suspend repayment indefinitely.
I still don’t understand the situation. You are buying now, but will only get the house handed over in 10 months and want to renovate then. When is the purchase price due? Already now? Does the loan also include amounts for the renovation, which will only be drawn later? That means full disbursement only in a year? Also watch out for possible commitment fees in your case. I had "free" half a year, after which they applied to amounts not yet drawn. This could particularly affect you if the purchase price is only due upon handover.