Single-family house Bauhaus style living area 180m with double garage

House connections are too brief. Painting work is very brief, especially if it is to be smooth fleece. What is completely missing: removal of earth masses, possibly additional effort for foundation, etc. Or is all that included in the shell construction? Is the plot completely flat? Is there a soil report? Does the terrain possibly need to be modeled or supported? What hit us hard and we did not have on our radar: stair railings, gallery railings, the staircase in general, special window requests. For sanitary and electrical work, I would also plan a good buffer. Exterior facilities are completely missing on your part. You can very quickly spend a lot of money there. You don’t want to be walking over pallets into the house for years... I agree with , if you are planning with a cellar, the house could be somewhat smaller with a good floor plan. There are really experts here. Have a general contractor/construction manager calculate the house for comparison. We build with a construction manager (architect = contractor) and I have to say that I find the fixed price very pleasant. Of course, additional costs can arise there as well, but only if you order something special yourself. (At least it works like that here. But it can be different elsewhere. It will depend on how good the general contractor/construction manager is.) If you already have the plot, you are under no pressure to commit to someone too quickly. Drive through the construction areas near you and ask around. Who has built what, who was satisfied in what way. That’s how we did it and hit the jackpot.

I overlooked that your father is a landscape gardener. But materials also cost...

One more thing. I personally think awarding contracts individually in the current situation is harakiri. Unless you can reduce your work to at least 50% part-time for a year. All the interface hassles, the coordination effort... Someone is constantly just not showing up. Sometimes you don’t even get any offers or only defensive offers with absolute sky-high prices. I wouldn’t put myself through that. But that always depends a lot on personal circumstances, nerves, and abilities. If the roofer runs away from you, you have the stress. If he runs away from the general contractor, he can see where to find another one. I think that’s a big difference. The roofer probably doesn’t care as much about offending an individual client as he does a general contractor from whom he might still get one or two orders even in lean times... That’s also a networking issue. Of course, the GC "service" is not free. But look deeply into your eyes at what you want and what you can deliver. My vote would be clear, also because of the current situation in the construction industry. But you will find just as many advocates for awarding contracts individually. Everything has its pros and cons.

The upper limit for the entire project is 800K€. The first installment is 655K€. I cannot assess the prices because I do not know what services are behind them. The list certainly reads well - but what does that mean. It doesn't help you much if I consider it feasible. What is needed is very good planning, discipline to stick to the plan, and consistent recalculation. The time invested there reduces the likelihood of unpleasant surprises.

Our construction became more expensive than originally planned. There are two drivers for this: 1. Earthworks with a higher proportion of soil class 7 than previously expected despite the expert opinion. 2. In detailed decisions, we did not pay much attention to an achievable budget.

What works very reliably - and here I disagree with the "harakiri" statement of - is the reliability of the craftsman companies and their coordination with each other. The carpentry company (it is a wooden house) receives an extra budget for coordination.

To avoid stress, you can do quite a bit yourself:

[*]communicate clearly [*]decide quickly and firmly [*]respect your craftsmen and their work [*]be happy and show it [*]state clearly and objectively what you are dissatisfied with [*]catch people when things are going well and praise them for it [*]be calm in events you cannot change [*]be present on the construction site [*]grant the craftsmen the money you pay. They deserve a good margin for good work.

Hampshire, that is just your experience now. I can only report the exact opposite and consider your list as a matter of course. It was of no use. We had exactly the situation of MadameP.

Something can always happen, good things too, and our experiences are neither representative nor transferable. Therefore, restricting oneself mentally in advance is a questionable consequence. First, focus on your own wishes and ideas and then check the ways to get there instead of excluding a path from the start is purposeful. Which path is then taken is a decision that will be made.