Is the cost estimation by the architect realistic?

I have a construction manager for €65 net/hour through an acquaintance. I definitely think I will save on the construction management by going through the architect. I’m still not quite sure about service phase 5. However, I definitely want the electrical planning to be done by a smart home expert. Regarding the controlled residential ventilation, the architect has already indicated that he’s out of that. Whether service phase 5 is worth it for the rest, I somewhat doubt. My craftsman colleagues say different things. The carpenter might be a bit above the planned budget without personal contribution, while plumbing and heating would be below. Unfortunately, I don’t have anyone directly for the shell construction. Here, personal contribution might possibly be an option through indirect ways, but that doesn’t really help me assess the costs right now.

Question to the pros here. If I continue after service phase 4 without an architect, what is the process then? I go to the shell builder with the floor plans and they can make me an offer based on that? There must still be some detailed information missing, right?

Question to the pros here. If I continue after service phase 4 without an architect, how does the process go? I go to the shell builder with the floor plans and they can make me an offer based on that? There must be some detailed information missing here, right?

We did it similarly with our general contractor. We had a floor plan (from a Polish project catalog :) ) and went with that. You do need to know the expensive stuff, whether you want it or not. Here are a few examples: - Type of heating (gas boiler, air-water heat pump or ground-water heat pump with deep drilling or surface collectors) - Controlled residential ventilation yes/no - Fireplace - Electric shutters? - Smart home? These are the price drivers. For upgrades (better bathtub, expensive window sills, more sockets....) I would budget at least 10k.

That is all already settled so far. For me, it was purely about the shell construction. Everything comes together there - meaning it should be clear which lines need to be cast into the ceiling. But is the floor plan and the structural analysis sufficient for the bricklayer? There are also corresponding requirements/wall thicknesses for KfW that must be adhered to.

Question for the pros here. If I continue after performance phase 4 without an architect, how does the process proceed? I go to the shell construction company with the floor plans, and they can make me an offer based on that? Surely, some detailed information is still missing here, right?

I think that’s pretty risky… I can somehow understand going to a general contractor with the plans, but going to the shell construction company, meaning you do individual contracting without detailed planning?? What about the building ground, who supervises the foundation? How are details executed? How are interfaces with other trades defined?
Despite having a (mediocre) architect, we had problems for years after construction that were due to missing detailed specifications.

Can you give examples for this? The foundation should be specified by the shell builder, what he wants or better yet, he should do the excavation himself right away. Otherwise, I can hardly imagine where there could be major problems if each trade reviews the overall plans in advance. But maybe I am just a bit too optimistic. The shell dimensions are already specified. From the architect starting at service phase 5, I only see massive potential savings and I am currently wondering if I really need all of that.