Cost estimate architect single-family house. Your assessment

For exactly these reasons, we chose a general contractor with a turnkey execution. It will always be more expensive anyway, because in the post-contract phase there will still be some changes desired. But such a jump from 390 per m3 to 440 per m3 --> ouch.

450.00/m3 per m3? Are you sure about that? That's 100 above what the architect estimated. Doesn't it also depend a bit on the region? Near Paderborn, but rather rural and not in the city

I am quite sure that my numbers are not far from reality; perhaps lower for your region, but not much less. Your architect's design is successful – in my opinion it will not work to fit another room on the ground floor – but it has its justified price. The large base slab and several offsets in it already cost quite a bit; the earthworks for it are also more complex. Then the combination of flat and shed roof; with the split level, the builder cannot perform magic (pour one continuous concrete slab), but must found on different levels. Rhenish regards

Can you say anything else about the floor plan?

Yes. First of all, I don't understand why you are being presented with a draft that apparently does not include the complete desired room program. Furthermore, the draft exceeds your budget framework, making realization unlikely.

Therefore, a discussion does not make much sense.
Basically, I always find it good when the natural terrain is incorporated into the design, which is why an L-shape with split-level can also be appealing.
Here I miss an even clearer zoning on the ground floor, specifically a more distinctly separated parent area with its own bathroom, a guest WC, a rethinking of the circulation paths (why do you have to carry used laundry through the dining room and the kitchen?), a streamlined building mass, etc.

We were also a bit frugal when he suddenly came up with cost accounting because we had different specifications.
What do you think about the idea of bringing the sun from the southwest into the large northeastern backyard through the single-story front part with the small shed roof? That is actually how the L shape originated. Or do you think the importance of the sun in the garden is overestimated? We are a little afraid of getting too little sun in the backyard, so we thought the idea of the L shape was quite good, except that it currently blows the costs.

Regarding the platform stairs, which take up a lot of space. What alternatives are there to save a little space? In my opinion, the hallways are currently too large and space is wasted because of the stairs, see below near the living room where the PC is marked.

I also don’t find the laundry and going through the kitchen ideal.

Or do you think the sun in the garden is overrated? We're just a bit afraid of not getting enough sun in the back of the garden, which is why we liked the idea of the L shape, except it currently exceeds our budget.

You have to decide what is important to you. Especially with larger gardens, there are plenty of options to have sun or shade at any given time depending on your preference.

I always find building structures with multiple wings or arms appealing. Especially if a clear zoning and nice sightlines are planned. However, due to the complex structure, it doesn't come cheap, since it's basically a combination of a bungalow and a one-and-a-half-story house but with shared utilities, access, etc.

But this should be designed and discussed initially completely without CAD.

Hello,

Regarding the platform staircase, which takes up a lot of space. What alternatives are there to save some space? In my opinion, the hallways are currently too large and space is wasted because of the staircase; see below in the living room where the PC is drawn in.

It is true that a platform staircase takes up a lot of space; on the other hand, in the presented design – due to the separation from the ground floor to the lower level – not so much; here I personally find it – against the wall – almost too confined. Of course, you could have a straight staircase planned, but I fear that then the split-level would appear even more like "trying too hard" rather than "skillful." A separation of the levels, as you have in mind, in my opinion needs space to be effective.

On the other hand, I agree with "Wanderdüne" that it is pointless to continue discussing this design, as it will neither fit your budget nor meet your requirements. And regarding the sun issue: I find it completely overrated, because you have sun in every part of the garden at some point; you just have to move along afterwards. By the way, there are also plants that prefer partial shade.

Rhineland greetings