Old building renovation (1966): Two-family house - floor plan sketch

The terrace is just huge and simply suitable for bigger barbecue parties - for that reason we naturally wanted to keep the option open.

Man! And I had already planned a lounge with armchairs, a fireplace, and a bar right there! Screw the baby room! :D

The terrace may be large. Barbecue party for more than 10 people Everything from the grill to drinks to forks must be carried up and back down. Baby or children sleep, party can't go on upstairs Children turn into teenagers, suddenly they hang out on the terrace at night with their friends or briefly go outside to smoke

By the way, toddlers and children live outside. I would rather invest the money for the hallway in the garden access.

You don’t know what kind of parties these are; maybe being close to the bedroom is important? ;-P

No, seriously. You don’t really believe you’re going to lug your grill stuff from the ground floor upstairs and then go back down for every beer. Forget it. As I already said: better to create access to the garden from the balcony below (or from the home theater room) and set up a comfortable grilling area there. You can have smaller meals at a small table on the balcony, but a big Sunday breakfast or a grill party with friends is better there.

The terrace upstairs is basically only for the cigarette afterwards or to put the baby outside (one of my nephews slept best outside as a baby, even when it was freezing cold).

I forgot where north was. One idea would be, of course, to give this luxury terrace to the kids and move the bedroom with dressing room to the upper right as per the plan, turn the kids’ bathroom into the parents’ bathroom and vice versa, and then enable at least two kids’ rooms to have direct access to the terrace. That would also make the long and ugly hallway obsolete.
Additionally, you could think about building a staircase from this terrace so you can get into the garden from there, too.
But never ever would I carry that gear upstairs and then back down again for grill parties! And then there’s a baby room and the kids’ rooms. If the little ones are still small, do you really want to party right next to them?

Forget that real quick!
I currently live in an apartment with a terrace at the basement level, the kitchen is upstairs on the ground floor. We hardly ever use the actually very nice terrace because it’s just too impractical. Upstairs there is only a very small terrace, just enough space for one chair, no dining area. Usually we grill there (we have a gas grill there) and eat inside by the open terrace door. Stupid!
We’re already looking forward to our house where the terrace is directly accessible from the kitchen and there are no stairs in between.

What the whole topic of floor plans has to do with our vacation measures, cars, etc., I don't know

This was supposed to illustratively demonstrate the dimension of the abstract figure "additional costs": Simply tripling the additional costs means that for normal families (usually with about one and three-quarter average salaries combined), vacations outside of their balcony area are canceled, and the car is certainly heading towards a historic license plate. However, if one has a flood of money in the money storage, then it’s all easy. Or if one only consumes homemade bread and tomatoes from their own garden, knits every sweater themselves, etc., then one can also say: we don’t want other hobbies than heating a huge house. If you are such a freak – fine by me. I just wanted to say that for average families, blowing that much money on one household item has the consequence that poverty rules elsewhere. So either heating costs as if in a normally sized apartment the windows were open all day, or a week-long beach vacation.

So, I printed out kahos draft and scribbled a bit on it:

K1 and K2 have access to the terrace, K3 has a private balcony, but it is a bit smaller.

The parents' area has shifted to the right; the narrow WC was removed, possibly also adding the area with the dashed line to the bathroom. For example, for a more than comfortable shower! A sauna could also be added, depending on how large the dressing room needs to be. I would find the entire former children's room as a dressing room too large, better to enlarge the bathroom instead. Access to the parents' area only through the one door; the bedroom can only be reached through the dressing room. If desired, you can keep the door to the former children's room 2 (I would remove it). Instead of a sauna, you could also consider a utility room for laundry washing, but that would probably require more effort as installations would need to be done.

oops, I just noticed: the door between K1 and K3 must of course be closed.

One could also separate the entire children's area with a door in the hallway.

I assume that the wall between the bedroom and the dressing room in my proposal is load-bearing; otherwise, I would reduce the bedroom in favor of the dressing room, moving the wall downward on the plan (in the original) or to the left here. Then you have a really nice large dressing room where you could possibly set up a small workspace or a vanity. Many possibilities!

The remaining wall with the door to the former children's room 1 should of course also be removed.