ᐅ Single-family house with 190 m² living area and a 55 m² basement apartment, situated on a gentle slope
Created on: 1 Nov 2025 13:04
A
Andixxx
Hello everyone,
I have planned a house here that largely meets our ideas and requirements. However, we are still unsure about the exterior appearance. Costs and technical reliability also play a role in this decision.
Description:
Two variants have emerged that differ mainly in the roof and roof shape:
For variant 2, I expect additional costs of about €20,000 to €30,000 due to the extra roof structure, the absence of a concrete ceiling, and the relatively expensive roofing materials.
Visually, we prefer this variant, and it also offers better protection against moisture.
However, this layout is quite unusual. Since I have been dealing with it for some time, I might have gotten used to it – therefore, I am interested in your opinion on this.
The facade could be entirely executed as an external thermal insulation composite system (ETICS) in white, or the basement level could be clad in brick (red-black or light gray-black) – an additional cost of about €25,000.
The eaves will be clad from underneath, with no exposed wood.
I designed the draft myself and created a 3D model (in countless variations), and have since hired an architect. However, this architect has other ideas that we do not like – so that part is currently a bit challenging.
In addition, I would appreciate your assessment of the costs.
I have currently budgeted €780,000 for construction and €120,000 for additional costs. The plot is already owned.
Thank you in advance for your constructive comments.
I have planned a house here that largely meets our ideas and requirements. However, we are still unsure about the exterior appearance. Costs and technical reliability also play a role in this decision.
Description:
- 1.5-story construction
- Plot size: 1,150 m² (12,379 sq ft)
- Living area: approx. 190 m² (2,045 sq ft)
- Granny flat: approx. 55 m² (592 sq ft)
- Building size: 10.75 m wide and 15 m deep (35 ft 3 in by 49 ft 3 in)
- Due to the plot width of 19 m (62 ft 4 in), the double garage is integrated into the house but structurally separated.
- Garden orientation: East-Northeast
- Built with an architect and individual contracting of builders
Two variants have emerged that differ mainly in the roof and roof shape:
- Setback floor with flat roof and parapet
- Setback floor with shallow pitched roof (16°) and eaves
For variant 2, I expect additional costs of about €20,000 to €30,000 due to the extra roof structure, the absence of a concrete ceiling, and the relatively expensive roofing materials.
Visually, we prefer this variant, and it also offers better protection against moisture.
However, this layout is quite unusual. Since I have been dealing with it for some time, I might have gotten used to it – therefore, I am interested in your opinion on this.
The facade could be entirely executed as an external thermal insulation composite system (ETICS) in white, or the basement level could be clad in brick (red-black or light gray-black) – an additional cost of about €25,000.
The eaves will be clad from underneath, with no exposed wood.
I designed the draft myself and created a 3D model (in countless variations), and have since hired an architect. However, this architect has other ideas that we do not like – so that part is currently a bit challenging.
In addition, I would appreciate your assessment of the costs.
I have currently budgeted €780,000 for construction and €120,000 for additional costs. The plot is already owned.
Thank you in advance for your constructive comments.
As a result of the requirements, I would place the technical room, storage room, and bedroom with bathroom in the basement. On the ground floor, the open-plan living area and an office/hobby/guest room, which could also serve as a bedroom in old age. Doors at 100cm (39 inches). I currently see four fully sized rooms suitable for living: one in the basement, one on the ground floor, and two on the upper floor. This doesn’t necessarily have to be the case. However, if you remove one level, namely the upper floor, you can still create a spacious design. This would also allow for the desired flat roof. This is the needs-based planning according to your room program for this sloped site.
familie_s schrieb:
I don't understand the additional costs for the gable roof.Yes, it also looks somewhat "unusual" to me. Here is what I have as a quote; the house itself has upper floor exterior dimensions of 11.5 meters x 9 meters (38 feet x 30 feet). Net prices; insulation naturally depends on the building standard and is the same for flat roofs as well:
Thank you for the comments and suggestions.
I am just an engineer, not an architect, but I have clear ideas about my house. The architect was supposed to revise these ideas, but that didn’t work out. In my opinion, his designs were too extravagant and would have limited the usability. It also wouldn’t have been cheaper.
The technical room is in the basement and has no window. In my view, this is not necessary since it also houses the ventilation system.
The guest toilet is an interior room; in another version, it had a window. Due to the open-plan layout, we wanted a room adjacent to the kitchen that could also be used for additional appliances (so that not everything is cluttering the kitchen) and that can be closed off with a door. That was more important to us than a guest toilet with a window. Also, it creates clear axes and pathways.
The basement is too large not to be used for living space. Therefore, I utilized the sloping site on the right side to make the right part of the basement suitable for a hobby room, guest room, etc. The basement is half above ground at this point. At the same time, this area is designed like a separate apartment, so it could be used accordingly.
From a structural point of view, it makes sense to construct the upper floor entirely as a timber frame structure; this would essentially be a differently shaped roof frame. With the shallow gable roof compared to a flat roof, I would have no concerns regarding the risk of moisture damage. However, the architect wants to build it with solid construction and says that a bit more steel and concrete is affordable.
Regarding construction costs, I am somewhat skeptical as well. But I can do the bathrooms myself; the fireplace can also be installed later (only the chimney). I can also handle the basement finishing myself, including electrical work, underfloor heating, tiling, and bathroom. The carport and terrace cover don’t need to be done immediately.
Originally, I mainly wanted to discuss the roof shape and thus the external appearance. Flat roofs with parapet walls are common everywhere. But what do you think about the shallow gable roof?
I am just an engineer, not an architect, but I have clear ideas about my house. The architect was supposed to revise these ideas, but that didn’t work out. In my opinion, his designs were too extravagant and would have limited the usability. It also wouldn’t have been cheaper.
The technical room is in the basement and has no window. In my view, this is not necessary since it also houses the ventilation system.
The guest toilet is an interior room; in another version, it had a window. Due to the open-plan layout, we wanted a room adjacent to the kitchen that could also be used for additional appliances (so that not everything is cluttering the kitchen) and that can be closed off with a door. That was more important to us than a guest toilet with a window. Also, it creates clear axes and pathways.
The basement is too large not to be used for living space. Therefore, I utilized the sloping site on the right side to make the right part of the basement suitable for a hobby room, guest room, etc. The basement is half above ground at this point. At the same time, this area is designed like a separate apartment, so it could be used accordingly.
From a structural point of view, it makes sense to construct the upper floor entirely as a timber frame structure; this would essentially be a differently shaped roof frame. With the shallow gable roof compared to a flat roof, I would have no concerns regarding the risk of moisture damage. However, the architect wants to build it with solid construction and says that a bit more steel and concrete is affordable.
Regarding construction costs, I am somewhat skeptical as well. But I can do the bathrooms myself; the fireplace can also be installed later (only the chimney). I can also handle the basement finishing myself, including electrical work, underfloor heating, tiling, and bathroom. The carport and terrace cover don’t need to be done immediately.
Originally, I mainly wanted to discuss the roof shape and thus the external appearance. Flat roofs with parapet walls are common everywhere. But what do you think about the shallow gable roof?
H
hanghaus20233 Nov 2025 14:34What is the situation like in the area? Is there a market for the granny flat / accessory dwelling unit?
Why don’t you want to mention your budget?
I prefer the gable roof. In my opinion, it is not more expensive than the flat roof.
What exactly was too unusual about the architect’s design?
Why don’t you want to mention your budget?
I prefer the gable roof. In my opinion, it is not more expensive than the flat roof.
What exactly was too unusual about the architect’s design?
Andixxx schrieb:
Thank you very much for the comments and suggestions. But you only read or understood them half-heartedly, didn’t you?
Andixxx schrieb:
Regarding construction costs, I am a bit skeptical as well. But I can do the bathroom myself, the fireplace can be added later (just the chimney), I can also handle the basement finishing (electrical, underfloor heating, tiling, and bathroom). The carport and patio roof don’t have to be done immediately. You didn’t post your message to have the total construction cost checked, but rather to get an assessment.
Yes, you can do a lot yourself or initially leave some things out. But what remains as an affordable and buildable base?
Regarding the no-go’s you’ve now encountered as an engineer due to your question.
Let me remind you:
Andixxx schrieb:
.. constructive comments. Andixxx schrieb:
The technical room is in the basement and has no window. It’s not about having a window, but that with the location you chose and the garage, you are building over the utility lines. That is not allowed!
Secondly: you are only permitted to build a single-story house, but you planned a two-story building. Whether with or without a pitched roof. Neither can be disregarded now.
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