Semi-detached house feasibility assessment ideas notes

I'll get started on tinkering then.

That makes little sense as long as you don't have the exact specifications for the roof.

That makes little sense as long as you don't have the exact details of the roof.

Correct. You should still check the roof pitch. Possibly the technical equipment fits into the attic! Plus more or less storage space. But then there should also be a proper staircase leading up.

Also take a look at the floor plan of the Mainz 128 from Town & Country to see how they solved it on 6x10. 3 children's rooms on the upper floor and 1 studio for the parents upstairs where you could also separate a small office.

And: say goodbye to the shower on the ground floor and rather install a handheld shower plus floor drain in the WC, where you can also rinse your dirty clothes. The sticking point is always the lack of utility room and storage space. The latter can be created to some extent (for insensitive items) in the garden, plus a solution under the stairs; for that I would definitely bring in a good carpenter who can get the most out of it.

Another alternative would be to completely do without the WC on the ground floor, take a bit away from the kitchen and tailor a utility room out of it.

Two more aspects:

Currently, three of us live on 84 m² (including half of 2 balconies)). With the semi-detached house, it wouldn’t be less with full occupancy, rather more (a bit difficult to calculate the net area here). So we are more or less used to it.
The biggest problem at the moment is that I don’t have a separate study, which would be available in the semi-detached house.

1) You are probably living in an apartment right now. Let’s say 80 m² of real living space with 3 rooms. You can equate the hallway in the apartment with the staircase on the ground floor. Now there are still two hallways and staircases added (first and attic floor), that’s already 15 m² extra. Plus 5 m² of technical space, which you probably had externally in the basement until now. That means your house would already need 100 m² to offer an equivalent amount of space as the apartment. And then there are 3 new rooms added!

Based on the external dimensions depending on the knee wall and roof pitch, about 130 m² of living space will result—rather less.

Then each of the three new rooms has at best 10 m² on average. That’s how it is. And now you also want an extra guest WC with 4 m²... and the washing machine, which until now may still have been in the basement, is also added plus the storage space that was previously available in the basement compartment also needs to fit inside the shell of your house, cutting into the living area. Then we’re at 8 m² per new room. I think that’s rather less than you are used to!

2) Think again about the study — in your case that is a luxury. In my old apartment I only had the bedroom available. If the partner does not work shifts, they have to get up together (organizational issue!) and then the parents’ bedroom is usually empty all day, a work corner can be quickly set up there. That would save one room.

PS: Are dormers allowed?

And another aspect that just occurred to me is probably due to your CAD tool: ask the general contractor directly about the materials used for the exterior walls (stone, brick, insulation, thickness). You assumed 40 cm for the masonry, which is realistic for the free side. But on the party wall, 17 cm plus gap, so around 20 cm, could already be sufficient. Then you would have 20 cm more usable width inside, which would definitely be noticeable and give you more space.

Topic fuse box in the HAR: there must always be a free distance of 1.2 to 1.5 m (depending on the utility provider) from the box to allow the electrician to work. The washing machine could already be placed behind it later, as it can be moved if necessary, but a heating system or water heater in this zone is a no-go!

Two more aspects: 1) you are probably currently living in a multi-story apartment. Let's say 80 m2 of actual living space with 3 rooms [...] Depending on the knee wall and roof pitch, an area of around 130 m2 living space will result based on the exterior dimensions—rather less. [...]

I recalculated. Without balconies, I have 73 m² (yes, I was probably cheated out of a few square meters with the apartment). That makes 24.4 m² per person. If I calculate 125 m² pure living space in the house, that's 25 m² per person. Then there are about 200 m² of garden instead of 7 m² of balconies. So I believe that is an improvement.

2) Think again about the study room—that is a luxury in your case. [...]

You are probably right for about 95% of families; for us, it is just not like that. Just assume that we have daily schedules shifted by 6 hours.

PS: are dormers allowed?

I have no idea, they weren’t suggested to me, I didn’t notice any passing by the property in the neighborhood either, but I would think they exist. There’s everything possible there, from gable to hipped to flat roofs, so why not dormers as well.

And another aspect that only just occurred to me [...] On the party wall, however, 17 cm plus gap, so about 20 cm could already be sufficient. Then you would have 20 cm more usable width inside; that would definitely be noticeable and would give you some breathing room.

Very good hint, I will inquire about that right away.

Topic fuse box in the utility room: there must always be a free space of 1.2 to 1.5 m (depending on the basic supplier) in front of the box so that the electrician can work. [...]

Thanks for the hint. And how big is such a box now? I assumed (W60xH80xD30) and now have 131 cm in front of the laundry basket, so that should be okay. I have another question about the air-water heat pump: is it allowed to be mounted on the wall (like a gas boiler)? I have now placed it above the buffer tank. But maybe there are also regulations that contradict this? Thanks and regards Tolentino