Core renovation - where to develop additional living space?

Hello everyone,

My wife and I (both 29 years old) are facing the decision of buying a property from 1967. We have been considering for some time whether purchasing and completely renovating the house would be worthwhile and how best to utilize the existing potential. Since neither of us has experience in the construction industry, we have developed some ideas but are often uncertain about feasibility and costs. Therefore, we would greatly appreciate your expert feedback! At the same time, we hope you can inspire us with new suggestions that we might not have considered yet. Here are some key facts about the house:

Bebauungsplan/Einschränkungen
Location: Südbaden (near Freiburg)
Year of construction: 1967
Construction type: solid construction (30 cm thick exterior walls made of brick)
Basement ceiling: known "Kochdecke" here (hollow body ceiling)
Living area: 130 m²
Usable area: 133 m²
Plot size: 633 m²
Slope: no
Building window, building line and boundary: no development plan available
Edge development: see above
Floors: without screed
Number of parking spaces: 4
Number of floors: 1.5
Roof type: gable roof
Style: ---
Orientation: southwest
Maximum heights/limitations: no development plan available

Anforderungen der Bauherren
Style, roof shape, building type: ---
Basement, floors: ground floor, upper floor

IST rooms on the ground floor: 1 cloakroom, 1 guest toilet, 1 kitchen, 1 pantry, 1 dining room, 1 living room
SOLL rooms on the ground floor: open living-dining area, guest toilet with shower, cloakroom
IST rooms on the upper floor: 1 bathroom, 3 bedrooms
SOLL rooms on the upper floor: 1 bathroom (significantly larger), 1 master bedroom, 1 child’s room, 1 office
Additional requirements: 2 children’s rooms
Expansion reserve: attic, garage attic (adjacent to the house)

Number of persons, age: 2 adults (29 years old), 1 child (1 year), 2 additional children planned
Office: home office
Overnight guests per year: 5
Open or closed architecture: open
Conservative or modern construction: mixed
Open kitchen, cooking island: open with cooking island and counter
Number of dining seats: 6
Fireplace: yes
Music/stereo wall: no
Balcony, roof terrace: balcony
Garage, carport: garage available
Utility garden, greenhouse: no

House design
Personal price limit for core renovation and extensions, including equipment: 450 TEUR
Preferred heating technology: underfloor heating with heat pump

We do not yet have static plans, so we can only estimate (non-)load-bearing walls based on the wall thickness.

Our ideas for expanding the living space
The main problem with the property is the insufficient living space. We have considered converting the garage attic. However, the garage is about 1 m lower than the house, so a "simple" breakthrough from the upper floor to the garage attic would not be easily possible (one would hit the roof structure). Our idea was therefore to remove the garage roof and increase the floor height so that a breakthrough with stairs to the garage attic would be possible. What are your ideas and thoughts on this?

Another idea was to convert the house attic. Since the roof will be newly covered and insulated anyway during the core renovation, this seems like a "logical" step to us. However, currently there is only a folding ladder in the upper floor hallway that leads to the attic. A fixed staircase would need to be installed here. We have no idea where it could be placed without reducing living space. One idea was to expand the stairwell. However, we are unsure if this is possible with the roof orientation. What do you think about this?
Another topic is the heating. Because we want underfloor heating everywhere, we wonder how that could be implemented in the attic. Do you have any ideas?

Our ideas for improving the living space
Ground floor
Currently, a cabinet serves as a partition between the dining room and kitchen. Instead of an "open partition," we can imagine an L-shaped kitchen island with a counter.
Although we are fans of a pantry, we would give up the partition wall in favor of a larger kitchen. As a storage replacement, we imagine 3-4 tall cabinets (the windows in the pantry are probably impractically positioned for this). Perhaps another storage room can be realized between the house and garage (for vacuum cleaners and such)?
The dining room has no windows facing west. Here, we would install floor-to-ceiling windows – or even corner windows towards the terrace (facing south)?
Another idea would be to integrate a corner bench in the dining room to use the space more efficiently. Then the floor-to-ceiling windows would again be wrong.
In the living room, the position of the sofa is difficult. There are already windows and a door facing south. To keep the space between the living and dining room as open and spacious as possible, we would place the sofa in the corner in front of the windows facing north. This is unattractive but gives us free space for the children to play.
We would like to place a Swedish stove at the fireplace. Is there enough space there? Could a tiled stove with seating be installed here?
We are uncertain about the doors to the hallway in the kitchen and living room. On the one hand, open living would be nice; on the other, it might be advantageous to separate the floors from noise. Maybe remove the door in the kitchen and install a sliding door in the living room?
The cloakroom is practical and necessary, but we would like a small shower in the toilet. We are unsure how a floor plan could look.

Upper floor
We definitely want to enlarge the bathroom and give up the third bedroom for this. The remaining space could become the corridor to the breakthrough towards the garage.
There is a mini dormer window in the stairwell for lighting. We would enlarge this so that the two rooms on the right and left receive another window.
In the master bedroom (southwest), we want to add another window. For this, the dormer from the bathroom could be enlarged. Another consideration would be to install a large roof window above the bed.
Furthermore, we would have to accommodate the aforementioned stairs to the attic if we convert it into living space.

Attached you will find all plans. We have included our ideas in the file "IDEEN_EG_DG."

We look forward to your feedback and any suggestions on what could be made of this property.
Thank you very much in advance!
Family Lischli

Interesting project that you want to take on!

Shed dormer

I think you will get that approved from a building regulation standpoint. They would be subordinate to the house or the facade and are doable. Whether you need them in the bedroom, I doubt. If I were to do roof windows, I would put them on the side, not above the bed.

Furthermore, we would have to accommodate the aforementioned stairs to the attic if we want to convert it into living space.

I don’t see any significant area in the attic that could be useful for living purposes.

On the other hand, it could certainly be advantageous to separate the floors from noise.

What kind of noise are you expecting?

That’s unpleasant, but it gives us free space for the children to play.

I like that, but the room must be large enough for it, which it apparently will be here.
..
I don’t quite understand the stairs in the garage. Do you need more rooms? What is the basement like?

Thank you very much for your reply, ypg!

I don't quite understand the stairs in the garage. Do you need more rooms? What is the condition of the basement?

Since we want two more children, we need a total of three children's rooms in addition to the master bedroom. This is not possible with the current living space (especially since I also need an office for the home office). Therefore, the two ideas for expanding the living space, on which we would need feedback.

Summary: the house is worth it, but for other people (whose current and target states align better), the ideas for change will hardly be feasible here. I see this house no closer to being rejuvenated than 1995/2000, and that still at a price noticeably above new construction costs.