Convert storage area to living space in sandstone building

This project involves the opportunity to convert a hall/storage space into living space. The entrance and the “garage” are located on the ground floor, while the upper floor is basically a blank slate measuring 14.6x16.2m on which we could let our creativity run wild. The floor area of over 230m² is almost too large. The roof structure slightly dictates the room and window layout along the exterior walls. The challenge of this project is the relatively long building shape without light/windows from the sides.

Development plan/restrictions
Slope:
Northeast to southwest (see attachment)

Year of construction and condition:

[*]1912, last used as vehicle hall (ground floor) and storage space (upper floor)
[*]60cm sandstone exterior walls, gable walls upper floor made of solid brick approx. 30cm
[*]Partially basemented on the slope, basement exit at ground level
[*]Ground floor ceiling approx. 30cm, rests on massive columns and beams
[*]Roof covering and roof structure in good condition

Number of floors:

[*]Basement partially under the garden level
[*]Ground floor with entrance area, vehicle hall and courtyard entrance from northeast
[*]Upper floor with planned living area

Roof shape:

[*]Gable roof 45°
[*]Double-sided “dormers” with 30° over the entire width. Knee wall +2.57m upper edge of finished floor
[*]Theoretically open to ridge +7.90m upper edge of finished floor

Architectural style:
Northeast façade plastered, rest natural sandstone with solid brick components

Orientation:
Southwest

Number of parking spaces:
3x courtyard outside and 3x vehicle hall


Clients’ requirements
conservative or modern construction:
Building in existing structure

Number of people, age:
2+1 (mid-30s and toddler)

Space requirements on ground floor and upper floor:
2x children’s rooms and office. Otherwise the “usual.” The relatively large floor area allows for additional rooms (such as a storage room).

Office:
Part-time home office (1 workplace)

Overnight guests per year:
Sofa bed in the office is sufficient

Open or closed architecture:
Open living area. Sleeping area set back. Parents’ bathroom in the parents’ bedroom area. Guest bathroom near the children’s rooms (and office). Include roof truss construction as a style element. Ceiling in the living and dining room open upwards.
Wish: The ceilings of the other rooms above the beam level at approx. +2.95m upper edge of finished floor (visible longitudinal beams of the roof construction).

Open kitchen & kitchen island: yes

Number of dining seats: 6-8

Fireplace: no

Music/Stereo wall:
Sonos, nothing special

Balcony, roof terrace:
Roof opening and conversion to a loggia

Garage, carport:
Garage/hall on ground floor

Utility garden, greenhouse:
Garden section 500m² at basement ground level, accessed via stairs

House design
Who designed it:
Do-it-yourself based on measurements and photos. Model realized in pCon.Planner.

What do you particularly like? Why?

[*]Parents’ area with dressing room and bathroom as a closed-off area
[*]Open ceiling in the living area
[*]Loggia as a small outdoor area

What do you dislike? Why?

[*]Unequal sized children’s rooms. Child 1 is too large at 23m²
[*]Completely open kitchen. Difficult to do otherwise because of lighting situation and room layout

Where are you uncertain? Why?

[*]Entrance area directly leads into living space -> solution with best light utilization -> theoretically still space in the ground floor entrance area

Price estimate according to architect/planner:
So far only own cost estimate approx. €400,000

Personal price limit for the house, including equipment:
€400,000

Preferred building technology:
Air heat pump with combined or hygiene storage
Underfloor heating with 20cm floor buildup
Photovoltaic system on southwest roof
Central ventilation system
KNX as own work with planning service

If you have to forego, which details/extensions
can you do without:

[*]Longitudinal beams below the ceiling if it causes structural or cost issues.
[*]Possibly the ventilation system (cost)

Cannot do without:

[*]Lots of own work in wall design, floors, electrical, other helper work (manual skills are present).
[*]Conversion of attic (cold), ground floor and courtyard. We can also spruce these up later.

Questions upon questions
Why did the design turn out as it is now?
I have been reviewing it for a long time, changing things, rearranging rooms, and getting inspiration from other projects. Arranging the rooms all on one level is not easy. The separation of living, parents, and children enables short routes for all residents and a central gathering place.

Where are there still questions to clarify?
The design is mine, so it is naturally not clarified statically, energetically, or in detail. Another question is how all the materials will be brought into the building. My current idea is a temporary roof opening on the northeast side. Possible stuff would have to be placed in the courtyard at ground floor level.

What is the most important/fundamental question about the floor plan summarized in 130 characters?
I am slowly becoming blind to it. Maybe someone still has some inspiring and fresh ideas.

Ground floor plan: Garage and storage space


Upper floor plan: Living






Terrain gradient: The height difference is bridged with a floor/level or a wall.

… and the building authority allows to convert the entire 230 sqm into living space?

In renovation projects, it is always crucial for outsiders to understand the before/after changes. Commonly, new walls are shown in red, removed walls in yellow, and existing walls in black.
What does the entrance area look like currently, for example? Is the staircase already in that form?
The plan for insulation as well as drainage and irrigation is most important to me initially. Do you need to include internal insulation? Where are the connections for wastewater?
Beyond that, answering Yvonne’s question is fundamental.

A change of use is possible. As stated in the first post, the upper floor is completely empty. Only the beams of the roof truss, which can also be seen in the upper floor plan, give a bit of the structure. For this reason, I have not yet made any color distinctions. The current state is depicted on the ground floor and can remain as it is. The stairs are already present and can be used. This also determines the entrance situation on the upper floor. Perhaps I should have mentioned this in the first post. Since I come from the building services engineering field, I also considered feasibility in the designs. The wastewater is fairly flexible because we can route the drainage under the ground floor ceiling. Height, slope, and ventilation through the roof are all possible. The sewer connection is located in the bottom right corner of the plan. Nothing has been clarified energetically. Since the outer walls of the long dormers set back slightly from the sandstone outer wall, external insulation would be possible.

If the upper floor is completely empty, why don't you use the gables then? A wall runs directly up to a window there - how is that supposed to work?

You mean the right gable wall facing the courtyard? The room is not easy to integrate for several reasons and was therefore not considered in the design. The wall that runs towards the window is not a wall, but a height offset of about 50cm. The ceiling of the entrance area below, formerly reception and office, is correspondingly higher than the rest of the ground floor. The floor area of this section alone would be too small or you would have to build in a sort of two-story manner up to the ridge (at the height of the 2 windows in the gable wall). In addition, there is practically no knee wall in this area. I would consider this area as a potential expansion reserve.

The left gable wall only borders outside at the upper part. At the level of the upper floor, there is the open space of an adjacent hall. This is quite clear on the West elevation.

Sorry if the basic structure is not immediately obvious. If anything is still unclear, feel free to ask :D