ᐅ Floor plan: New construction on an existing bungalow basement, one-and-a-half stories
Created on: 19 Dec 2022 01:12
M
Mal Bauen
Hello to all forum members,
We are still relatively early in our building project and have many fundamental questions to clarify. Nevertheless, I would like to introduce the project here.
We recently became owners of a prefabricated bungalow from Streif Haus, built in 1987. It has a full concrete basement (by Betonkemmler).
Our plan is to demolish the bungalow down to the top edge of the basement and build a new house for our family (currently four, eventually five) on top. The existing basement (very solid construction) is to be integrated as a utility basement including a technical room. At the same time, the heating system will be modernized from oil heating to a heat pump.
Currently, we are in contact with both prefabricated house suppliers (Weberhaus, Danwood) and solid construction companies (Denkinger). The property is located in Baden-Württemberg (southern Baden).
Even though the floor plan is only a first draft, I would like to present it here for feedback (summary below).
In particular, I hope to get some thoughts on the following basic questions:
Here is the summary sheet (key points).
Many thanks in advance for your input, comments, and critiques. I will gladly report further developments here in the thread.
Development Plan / Restrictions
Size of the plot: 615m² (6620 sq ft)
Slope: North/South: <0.5m (1.6 ft) over 18m (59 ft), West-East: approx. 2m (6.6 ft) over 33m (108 ft) (see elevation profile)
Site coverage ratio: No development plan (Section 34 of German Building Code). The immediate neighborhood contains some generously built plots. We do not want to change the building footprint of the existing house but want to add a double garage (not currently present).
Floor area ratio: No development plan (Section 34 of German Building Code)
Building envelope, building line and boundary: No development plan (Section 34 of German Building Code). Property boundaries and existing building shown in aerial photo attached
Edge development: None
Number of parking spaces: None
Number of floors: 1.5 stories
Roof type: Gable roof
Architectural style: Modern detached family house
Orientation: see aerial photo. Entrance (currently): north
Maximum height/limits: No development plan
Immediate neighbors: Northern neighbor: 2 stories with flat roof. Southern: 1.5 stories with hipped roof. Western: 1.5 stories with gable roof.
Client Requirements
Style, roof form, building type: We want to transform the existing bungalow into a classic 1.5-story detached house with a gable roof and possibly shed dormers.
Basement, floors: Utility basement (existing, concrete basement), ground floor (living), upper floor (sleeping)
Number of persons, ages: Our family currently has four members (ages: 32, 30, 2, 0), with another child planned
Space requirements on ground and upper floor:
Ground floor: living room, kitchen (possibly with pantry), room for home office or guest room, guest WC with shower, cloakroom
Upper floor: master bedroom, 3 children’s bedrooms, bathroom
Office: family use or home office: Home office (100% for me)
Overnight guests per year: Few, less than 5 guests/nights
Open or closed architecture: Rather closed. Ability to separate kitchen and living room would be desirable.
Conservative or modern design: Modern
Open kitchen, kitchen island: Kitchen island not mandatory. Partly open kitchen: separation from living room would be good.
Number of dining seats: 5-8
Fireplace: Only if budget allows, not mandatory
Music/ stereo wall: No
Balcony, roof terrace: No
Garage, carport: Double garage
Utility garden, greenhouse: No
Further wishes/special features/daily routine, including reasons for preferences or exclusions: The technical room should be located in the existing basement (e.g., in the former oil heating room). A sensible circulation concept is very important: front door/upper floor stairs/basement stairs. Ideally, short distances between garage and house as well as good accessibility of rooms within the house.
House Design
Designed by: Initial draft from the prefab house supplier after first meeting
What do you especially like? Why?: (Almost) all room requests fulfilled. Good accessibility of upper floor rooms via centrally located landing. Short distances from garage to house thanks to new front door position (west instead of north). Spacious cloakroom area. Living room oriented south/east with a nice view.
What do you not like? Why?: The draft was created after an initial discussion of the project. Some ideas and preferences developed or changed later on by us:
- Existing concrete stairs in the basement will not be used, causing extra costs for upgrading the basement (new stairs, new room layout).
- (Small) pantry for food/storage on the ground floor would be great
- Better separation of kitchen and living room is desirable
Price estimate according to architect/planner: 520,000 € (approx. $560,000), turnkey (including 10kWp photovoltaic system with 10kW storage, fresh air heating with air-to-air heat pump), excluding demolition of existing bungalow, double garage, incidental building costs
Personal price limit for house including fittings: 700,000 € (rough estimate: demolition down to top of basement: 30,000 €, house: 530,000 €, incidental costs including basement statics: 50,000 €, double garage: 30,000 €, kitchen/furniture: 40,000 €, landscaping: 20,000 €)
Preferred heating technology: Heat pump with underfloor heating. If budget allows: ground-source heat pump with deep geothermal drilling. The prefab house supplier prefers fresh air heating.
If you had to give up something, which details or add-ons could you do without: Fireplace, new basement stairs
What can you absolutely not do without: Home office
Why is the design like it is now?
Individualized draft by the prefab supplier adapted to the existing basement footprint after discussing our rough (space) requirements.








We are still relatively early in our building project and have many fundamental questions to clarify. Nevertheless, I would like to introduce the project here.
We recently became owners of a prefabricated bungalow from Streif Haus, built in 1987. It has a full concrete basement (by Betonkemmler).
Our plan is to demolish the bungalow down to the top edge of the basement and build a new house for our family (currently four, eventually five) on top. The existing basement (very solid construction) is to be integrated as a utility basement including a technical room. At the same time, the heating system will be modernized from oil heating to a heat pump.
Currently, we are in contact with both prefabricated house suppliers (Weberhaus, Danwood) and solid construction companies (Denkinger). The property is located in Baden-Württemberg (southern Baden).
Even though the floor plan is only a first draft, I would like to present it here for feedback (summary below).
In particular, I hope to get some thoughts on the following basic questions:
- Has any forum member gained experience with building on an existing basement?
- Is there generally a preferred construction method for our project? We are still undecided whether to go for a prefab timber frame house or a masonry (brick or block) solid construction.
- So far, we have not discussed a double garage with the builders, but it will be needed. Where does it make more sense: northwest or southwest (directly next to the neighbor’s garage)?
- To what extent can the project be treated as a renovation with partial demolition in terms of building regulations? Background: Are there any possibilities for funding (still) available?
- What we want to achieve with the floor plan is short walking distances inside and around the house. Therefore, the main entrance was moved from the north side to the west side. However, since it is on the short side of the house, this results in more corridor space and longer routes inside (e.g., from the front door to the stairs to the upper floor). But as the saying goes, you have to accept some drawbacks — what is your opinion: front door facing north or west?
Here is the summary sheet (key points).
Many thanks in advance for your input, comments, and critiques. I will gladly report further developments here in the thread.
Development Plan / Restrictions
Size of the plot: 615m² (6620 sq ft)
Slope: North/South: <0.5m (1.6 ft) over 18m (59 ft), West-East: approx. 2m (6.6 ft) over 33m (108 ft) (see elevation profile)
Site coverage ratio: No development plan (Section 34 of German Building Code). The immediate neighborhood contains some generously built plots. We do not want to change the building footprint of the existing house but want to add a double garage (not currently present).
Floor area ratio: No development plan (Section 34 of German Building Code)
Building envelope, building line and boundary: No development plan (Section 34 of German Building Code). Property boundaries and existing building shown in aerial photo attached
Edge development: None
Number of parking spaces: None
Number of floors: 1.5 stories
Roof type: Gable roof
Architectural style: Modern detached family house
Orientation: see aerial photo. Entrance (currently): north
Maximum height/limits: No development plan
Immediate neighbors: Northern neighbor: 2 stories with flat roof. Southern: 1.5 stories with hipped roof. Western: 1.5 stories with gable roof.
Client Requirements
Style, roof form, building type: We want to transform the existing bungalow into a classic 1.5-story detached house with a gable roof and possibly shed dormers.
Basement, floors: Utility basement (existing, concrete basement), ground floor (living), upper floor (sleeping)
Number of persons, ages: Our family currently has four members (ages: 32, 30, 2, 0), with another child planned
Space requirements on ground and upper floor:
Ground floor: living room, kitchen (possibly with pantry), room for home office or guest room, guest WC with shower, cloakroom
Upper floor: master bedroom, 3 children’s bedrooms, bathroom
Office: family use or home office: Home office (100% for me)
Overnight guests per year: Few, less than 5 guests/nights
Open or closed architecture: Rather closed. Ability to separate kitchen and living room would be desirable.
Conservative or modern design: Modern
Open kitchen, kitchen island: Kitchen island not mandatory. Partly open kitchen: separation from living room would be good.
Number of dining seats: 5-8
Fireplace: Only if budget allows, not mandatory
Music/ stereo wall: No
Balcony, roof terrace: No
Garage, carport: Double garage
Utility garden, greenhouse: No
Further wishes/special features/daily routine, including reasons for preferences or exclusions: The technical room should be located in the existing basement (e.g., in the former oil heating room). A sensible circulation concept is very important: front door/upper floor stairs/basement stairs. Ideally, short distances between garage and house as well as good accessibility of rooms within the house.
House Design
Designed by: Initial draft from the prefab house supplier after first meeting
What do you especially like? Why?: (Almost) all room requests fulfilled. Good accessibility of upper floor rooms via centrally located landing. Short distances from garage to house thanks to new front door position (west instead of north). Spacious cloakroom area. Living room oriented south/east with a nice view.
What do you not like? Why?: The draft was created after an initial discussion of the project. Some ideas and preferences developed or changed later on by us:
- Existing concrete stairs in the basement will not be used, causing extra costs for upgrading the basement (new stairs, new room layout).
- (Small) pantry for food/storage on the ground floor would be great
- Better separation of kitchen and living room is desirable
Price estimate according to architect/planner: 520,000 € (approx. $560,000), turnkey (including 10kWp photovoltaic system with 10kW storage, fresh air heating with air-to-air heat pump), excluding demolition of existing bungalow, double garage, incidental building costs
Personal price limit for house including fittings: 700,000 € (rough estimate: demolition down to top of basement: 30,000 €, house: 530,000 €, incidental costs including basement statics: 50,000 €, double garage: 30,000 €, kitchen/furniture: 40,000 €, landscaping: 20,000 €)
Preferred heating technology: Heat pump with underfloor heating. If budget allows: ground-source heat pump with deep geothermal drilling. The prefab house supplier prefers fresh air heating.
If you had to give up something, which details or add-ons could you do without: Fireplace, new basement stairs
What can you absolutely not do without: Home office
Why is the design like it is now?
Individualized draft by the prefab supplier adapted to the existing basement footprint after discussing our rough (space) requirements.
H
hanghaus20231 Apr 2023 08:28On the ground floor, I would change the bedroom and bathroom layout like this. Who wants the bed placed under the window?
Hello,
I would skip the chimney. This saves having to create an opening in the roof. Future changes in fine dust emission limits seem too uncertain to me.
Place the balcony in front of the facade. This provides better thermal separation. It could be retrofitted later.
For the long dormer, you might also consider an asymmetrical gable roof.
The roof ridge might then be somewhat overdue.
I would skip the chimney. This saves having to create an opening in the roof. Future changes in fine dust emission limits seem too uncertain to me.
Place the balcony in front of the facade. This provides better thermal separation. It could be retrofitted later.
For the long dormer, you might also consider an asymmetrical gable roof.
The roof ridge might then be somewhat overdue.
Mal Bauen schrieb:
Several hours of collaborative idea development with the architect using pen and paper. I firmly believe that this is how you can recognize a true professional.
Also highly commendable is the garage that is not attached directly to the house. I would still keep the construction method flexible. The attic space is unnecessary, and if anything, a balcony would be a good idea. As always, I fully agree with the suggestion to forgo a fireplace. Remove the option of dividing the building into a two-family house from the wish list; this will ease the process in the right place.
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
M
Mal Bauen3 Apr 2023 23:55alles3d schrieb:
I would leave out the fireplace. [...] The future development regarding fine dust limits seems too uncertain to me. We see the development similarly but, interestingly, come to the opposite conclusion: Before new fireplaces are banned due to fine dust limits, we will still include ours now, hoping that existing fireplaces will be allowed to be used for a little longer. Possibly a naive thought...
alles3d schrieb:
Place the balcony in front of the façade. That provides better thermal separation. It could be added later.
For the long dormer, an asymmetrical gable roof could also be considered.
The roof ridge might then be overdue. We included the balcony partly for that reason, to achieve sufficient depth (cantilevered, without supports).
An asymmetrical gable roof is an interesting option; we need to see some cross-sections and elevations of that. Visually, it might be a bit too "modern" for us, but since we already have a one-sided dormer, the roof is basically asymmetrical as it is.
11ant schrieb:
I would still keep the construction method open. What we can imagine is a kind of hybrid construction:
- Exterior walls: aerated concrete, monolithic
- Ground floor interior walls: calcium silicate brick
- Ground floor ceiling/floor slab: concrete
- Upper floor interior walls: timber frame (flexibility for remodeling)
- Upper floor ceiling/floor structure: wooden beams
However, we will need further consultation here (especially with a structural engineer and energy consultant).
11ant schrieb:
Remove the option of dividing into a two-family house from the wish list; that eases things in the right areas. The higher KfW funding for a two-family house has steered our planning in this direction. I generally think it makes sense to consider the future already, even if everything might turn out differently (but that somehow applies to any planning, including those with a shorter time horizon).
Mal Bauen schrieb:
What we are considering is a kind of hybrid construction method:
- Exterior walls: aerated concrete, monolithic
- Ground floor interior walls: sand-lime brick
The manufacturer can also "imagine" this and offers both building materials.
Mal Bauen schrieb:
The higher KfW subsidy for the two-family house guided our planning in this direction. I generally find it sensible to think ahead for "tomorrow," even if everything may turn out differently (which applies to any planning, even those with a shorter time horizon). Subsidy-optimized product design usually only pays off for large housing developers. For the private homeowner, the additional subsidy offsets the extra costs, even if the romantic expectations tend to be higher ;-).
Mal Bauen schrieb:
We see the development similarly but strangely come to the opposite conclusion: before installing new fireplaces is banned due to fine dust limits, we are still including ours now, hoping that existing fireplaces will still be allowed to be used a little longer. Possibly a naive thought... I will leave that "expressly uncommented"...
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
H
hanghaus20234 Apr 2023 08:23Similar topics