Location of city villa or single-family house on 500 m2 plot - rectangular

just as little as to diffusely add extra square meters to the total area through greater house depth.

Well, I wouldn't want to distribute it diffusely, but rather explicitly allocate it to the open-plan living area and the children's rooms in depth. Or do you see any obstacles there (structural engineering?).

These 5 sqm will, relatively naturally, be significantly more expensive than the normal square meters;

Ok, then the bay window would be out anyway.

Well, I wouldn't want to distribute it diffusely, but rather target the all-purpose room and the children's rooms in depth explicitly. Or do you see any obstacles there (structural stability?).

What would be needed more in the dining area would be needed more in the dining area – not in the seating and cooking areas. Giving this additional building depth across the entire width would be six times what is needed (= unnecessarily expensive). Distributing this extra evenly over the entire width would only be twice what is needed; but at the same time only a third of what the dining area would require, so it wouldn’t really help there. Neither is a sensible alternative.

Ok, then the bay window would be out anyway.

These five square meters downstairs (and upstairs then also "hanging along" five) would be ten, which would cost like fourteen to sixteen. The offsets in the facade line and even already in the foundation line naturally come on top, but the additional square meters are not cheaper just because their enclosure becomes more complex. At least normally – but I do not rule out that your general contractor lumps all square meters together (however, his extra charge for blinds doesn’t suggest that).

These five square meters downstairs (and then also "hanging along" five upstairs) would be ten, which would cost like fourteen to sixteen. The protrusions in the facade and already in the foundation line of course add on, but the extra square meters aren’t cheaper just because their framing becomes more elaborate. At least in principle – but I don’t rule out that your general contractor charges all square meters at the same rate (however, his additional charge for the roller shutters doesn’t suggest that).

That’s the problem. You never really know what the general contractor actually charges, because everyone handles it differently. You can also be lucky and the general contractor only demands a trivial extra amount for the bay window. Other general contractors pile on extra costs there that will make your ears ring. Unless it totally contradicts the aesthetic sense, it would not only relieve the space requirements, but also break up the relatively tubular room shape, and the kitchen island would be optional again.

That is the problem. You never really know exactly what the general contractor is charging because everyone handles that differently.

Yes, well, I already had an area for the entire extension. That was 6 m² for 6,500. If he uses the same rate, we would be looking at 10-12 thousand euros more for 10 m². In a very first draft for the bank, there were 2 bay windows included and it was suggested that my flat rate offer was based on area, meaning that I could also order this house at the standard price. But that was not at all practical in terms of the floor plan for my requirements. Well, as I said, I will discuss this with the architect/general contractor and then I have to reflect and do some calculations...

Well, as I said, I will discuss this with the architect/general contractor and then I have to reflect and do some calculations...

These are all just suggestions. In the end, it also works in 40m² (see DIN ). I don’t think it’s a problem to leave out the kitchen island and plan an open-plan kitchen. What probably wouldn’t work or would be annoyingly cramped is the kitchen island and a table for 5 people.

So, the additional costs are here. 1,083 EUR per m² of additional space. Seems actually quite cheap, doesn't it? I just have to figure out where to cut back, especially since it won't stop at the additional construction costs. Painter and flooring will also cost more...

Regarding the stairs: the [GÜ] installs an open staircase as standard, which requires side stringers for the steps everywhere. He has agreed to reimburse these, and I can get a stringer staircase elsewhere. I assume this is not relevant for the building application, right? So I can decide later.

Fall protection costs 750 EUR more. That seems a bit high to me again. What do you say?

Best regards

Tolentino