It is easier to build with a developer or general contractor. They usually already have floor plans in the drawer that can be adjusted slightly. Therefore, these companies can usually estimate very well what the house will cost. The word "actually" should be emphasized here. Because even here, costs are often concealed or withheld and only appear little by little. 10-20% additional costs are not that uncommon and should be planned for. In this case, if the architect guarantees you a price (in writing) and miscalculates, he is usually insured... but here it also gets legally questionable... whether the costs arose because you wanted it differently, or because the architect was incompetent, or simply because too much time has passed and the craftsmen have increased the price. Depending on the case, the insurance pays or not. We deliberately decided against an architect because the individual contracting was too "hot" for us. We wanted as much as possible from one source, which has already paid off. We had trouble with a subcontractor but were able to resolve and settle it directly through the house provider. The subcontractor was not very willing to negotiate :) For me, it is important to have exactly one person to vent my frustration on. You unfortunately always hear phrases like "we have always done it this way" or "that is within tolerance" from craftsmen. With the craftsmen I personally hired, there were always problems, and in the end, we were the ones who lost out... Mostly cosmetic damages. So only build with an architect if you understand each other and agree. Otherwise, things can go wrong very quickly. Also, have references given to you and talk to the builders.