Construction costs for terraces, etc. in cost estimation according to DIN 27

Once again for clarification:

The south front of the house is 10m long and the house consists of a ground floor and an upper floor. In front of the south side, the floor slab of the ground floor cantilevers about 2m forward, which basically creates a balcony of 20sqm for the upper floor. Below it, a covered terrace of 20sqm is created for the ground floor. Also, the roof of the upper floor (=roof of the house) cantilevers 2m so that the balcony of the upper floor is also covered.

In total, therefore, 40sqm of covered terrace is created. These flow 1:1 without deductions or a 1/4 multiplier, but 1:1 into the NUF as well as the other parameters of the cost estimation. So in the cost estimation, it would make no difference whether this was 40sqm of normal living space.

And of course without support posts, what else would it look like

Joking aside. This is basically the point over which we stumble: we can decide whether we prefer normal space inside the house or an equally large terrace and it would make no difference in the cost estimation.

Joking aside. That’s basically the point we’re stumbling over: we can decide whether we prefer normal indoor space or a terrace of the same size, and it wouldn’t make a difference in the cost estimate.

No, exactly not... You have 20sqm terrace on the ground floor and 20sqm terrace on the upper floor, both covered. And both without supports. That means you have 2 x cantilever of 2x10m. That means significantly higher requirements for the statics (which probably already accounts for a large part of the costs). You have 2x10m area that needs to be sealed. Parapet or railing etc. You haven’t really dealt much with construction costs and how they arise, have you?

Just give some numbers... in euros! How high is the cost estimate for variant 1 and how high for variant 2?

that means proper concrete in the building Our ground floor also cantilevers 90cm over the basement. for that, the entire ground floor was shuttered to railing height. However, there is also one upper floor above that, so quite a load. Means more time and material use than normal masonry.

Yes, I also see the major cost factor in the static calculations and implementation. Therefore, I can imagine that.
Just tell me where the price estimate is. Basically, if you don't have to worry about the money, I would build it the way I like it better.

No wonder the architect comes up with the same costs as in [Variante 1]. Do you know how much a cantilevered flat roof costs?

We would also have liked a 1m concrete roof overhang around the house. But when the general contractor said that would cost almost 20,000 euros, we quickly discarded that idea.

What I do wonder, however, is how modest it will look in the end if a flat roof on the south side is cantilevered 2m. I've never seen that before.

Can't you upload drawings so it can be better assessed?

Unfortunately, I don't have any drawings that I could post here. It's not really about the aesthetics right now, but rather about the costs.

It's hard to swallow that, cost-wise, it doesn't matter whether I convert the terrace 1:1 into regular living space or not.

The roof overhangs also have the advantage for us of providing constructive sun protection. Otherwise, you practically have to always lower the blinds during the day. Then I don't need a view either...