Single-family house for a family with 2 children

"Equipment: 450,000" is very likely not feasible with ~245 sqm and the architecture. Garage included?

I have to agree. We have 203 sqm of pure living space plus a partial basement of 68 sqm (including 21 sqm hobby room) and 56 sqm garage and we are well above your set budget. You have quite a few offsets in your planning which makes the construction expensive. So much for the topic of costs. Regarding your plans. I basically like the style of your house in terms of its external shape. A few suggestions from me. In the entrance area, I would straighten the wall. But I assume the planner designed this wall slanted because of the doors. Is the bedroom on the ground floor intended to be used permanently or is this planned for old age? If permanent, I would consider whether you really want the exit to the terrace. Because this way your visitors can look into your bedroom undisturbed, which would bother me. I also don't like the slanted wall in the bathroom upstairs... Generally, I am a fan of separating the parents' and children's areas. That way you have the bathroom on one side and a children's room next to the bedroom on the other side. This would bother me. Do both children's rooms have to be located facing south? I would give the planner the task of designing the current storage area and child 1 bathroom, bedroom, and possibly a dressing room and move child 1 into the current bedroom. Reduce the current bathroom and design the storage room out of it.

With an architect you can generally add another 30% on top anyway

On what - on this statement?

Almost a third deviation - and that even "upwards" - just by involving a professional exactly where he is meant to be - how does that work?

The place on the plans is not exactly cheap for various reasons. But that "fits" in the context of a non run-of-the-mill house. The ground floor ceiling height is princely, the children's rooms are for a change not cage-like, and in some places the standard building dimensions are boldly exceeded.

The planned object seems to me to be significantly more extravagant than the budget, yes. But "without an architect" it would definitely be even more expensive.

I think the lower bedroom suite is poorly planned that way. You could easily accommodate a separate apartment or crown prince(ss) apartment there.

On what - on this statement?

Almost a third deviation - and that also "upwards" - just by involving a specialist exactly where he is meant to be - how does that work?

We have already discussed this topic several times... not because an architect-designed house is per se more expensive, but because it is generally built "differently." With an architect, you don't just have to select 3.5 doors or 2.5 roof tiles... but usually you have the entire market at your disposal. The architect generally also has quite a few good ideas during the planning phase, and all of that exactly is what makes it more expensive. Usually, however, the clients are not bothered by this because it is a different "target group" than the classic general contractor client...

not because an architect’s house is inherently more expensive, but because it is generally built "differently". [...] The architect usually also has quite a lot of good ideas in the planning phase and exactly all of that makes it more expensive.

If those are really good ideas, you ultimately get a nicer house for more money.

So you basically meant "designer house is more expensive than a weather-tight shoebox"? – but for the difference, a 30% markup would actually be a bargain.

However, an architect does not necessarily have to see themselves as an "artist" in the sense of "creation à la maître de cuisine". Most architects earn their living quite mundanely by planning and supervising Müller’s house on Müller’s plot. And very much so within Müller’s budget.

The OP has apparently decided on a model here that the Graubrot (plain bread) construction companies like to somewhat disparagingly call an "architect’s house". Such things don’t get cheaper by skipping the architect (i.e. construction management being done by the contractor aka putting the fox in charge of the henhouse, for the approval planning you need an architect anyway, whether transparently paid or priced in).

And, yes, clearly: such a "sculpture" is of course lit with LED strips, tiled with Gail, and even the guest WC faucet is from Dornbracht. To outfit it with rental apartment standard would also devalue the entire building. You don’t put crank windows in a Panamera.

That, however, does not make the architect the cost driver. Taste – for which everyone can have a different opinion – belongs to the builder. And they know that the menu gets more expensive downward.

There may well be architects who want to impose their understanding of architecture on the builder and convince them to upgrade from the coffee grinder to the palace. Here, however, I don’t believe anyone was pushed against their will away from the "Maggi fix for Bauhaus-style suburban villa".

As you yourself already said:

As a rule, however, this does not bother the builders because it is a different "target group" than the classic general contractor builder.

I'm also a bit surprised, did you tell your architect your cost expectations? After deducting fees, incidental construction costs, fittings, etc., there are still 1200 €/m2 left. That doesn't fit the house, building a house at this price is almost impossible.

So our architect is my father (he will also do the site supervision, etc.)... Regarding costs: He assumed €400 / cbm = approx. €450,000... The garage is additional (€250 / cbm): approx. €50,000 (I had previously stated this incorrectly). So total €500,000 without kitchen and garden installations.

@ 11ant: Well, a "bedroom suite" with 16 sqm is not that huge... It will be an office for the first few years and only later used as a bedroom when the children throw us out of the upper floor...

: We made the slanted wall in the entrance area so that we could still fit a window on the left and right and thus get some light into the hallway. The bedroom on the ground floor is only intended for old age. Yes, I don’t like the slanted wall in the upstairs bathroom either... Alternatively, a slanted wall in Child 1’s room would be possible... The hallway is also a bit too large for my taste... So far, we haven’t come up with anything better... Yes, we would also prefer to separate the parents' and children's areas. Although we plan to move downstairs later when the children are older. I’d prefer to have the children's rooms facing south rather than the bedroom (it just heats up)... We have already had the bedroom in the current layout as well. But then the closet had to go on the north wall and there we have a low ceiling height (2.30 m) due to the shed roof...