ᐅ Floor Plan Optimization for a Single-Family Home with a Secondary Suite
Created on: 19 Jan 2026 10:26
D
DieHnnH
Hello everyone,
We are a couple (both 34 years old) looking to build our home in a rural area of Baden-Württemberg. Important preliminary information: no children planned, but a dog. A separate apartment (granny flat) is mandatory with at least 23sqm (250 sq ft).
We would appreciate your input to help us avoid making major mistakes.
Development Plan / Restrictions
Plot size: 494sqm (5314 sq ft)
Slope: none
Site coverage ratio: 0.32
Edge building allowance: garage permitted
Number of parking spaces: 3
Number of stories: 2 full stories required
Roof style: gable roof with a pitch of 25–38°
Orientation: see plan
Additional requirement: separate apartment
Homeowners’ Requirements
Style: country house / modern Swedish style
Basement, floors: no basement, 2 full floors
Number of occupants, age: 2 adults (34), 1 planned dog, 1 person in separate apartment
Space requirements on ground floor and upper floor: 120sqm (1292 sq ft) for us plus at least 23sqm (250 sq ft) for the separate apartment
Office: home office, 1 person working fully from home
Guest stays per year: total about 5–15 nights
Open or closed layout: open
Open kitchen, kitchen island: open kitchen with kitchen island or U-shape preferred
Number of dining seats: 4–6
Fireplace: desired for coziness, small in size, probably not really necessary
Garage, carport: carport plus 2 additional parking spaces
Kitchen garden, greenhouse: small greenhouse plus kitchen garden
Other wishes / special features / daily routine, also reasons why certain things should or shouldn’t be: the most important space to us is the kitchen and living room combined as an open area. We want it to be cozy, which is very important. The building plot faces east on the edge of the village, with no further development planned in that direction. We really like this view, but we would also like the terrace to face south.
In general, we want to make the best possible use of the remaining garden and are looking for ideas on how to place the house on the plot to maximize garden usability. We understand the garden won’t be very large.
We both have home-centered hobbies that require space: my husband plays drums, I play piano—space needed upstairs. I enjoy baking, he enjoys cooking—space needed in the kitchen. I like to read—books require space too. We both enjoy gardening.
House Design
Designed by: architect (BU)
What do you like especially and why?
- Layout of the open space and size of the kitchen
- Location of the separate apartment
- Additional space gained upstairs. We originally considered a single-story extension for the separate apartment, but the architect said it’s more expensive than enlarging the whole house. This way, we can keep the technical room small downstairs and move the utility room completely upstairs. We would swap room usage upstairs: bedroom → utility room in the northeast, office → bedroom (this also allows a nice built-in wardrobe niche).
What do you dislike and why?
- The separate apartment has no room for a closet
- Unsure if the size of the open space is sufficient
- The bathroom is very large—like a ballroom. We considered extending the hallway to create a small extra storage room. However, this would reduce western light in the bathroom.
- We don’t like the windows and terrace doors at all yet
- Carport location: needs to be rotated and, in our opinion, moved to the boundary
Cost estimate according to architect/planner: €600,000 including secondary construction costs
Tasks we will do ourselves: roofing, purchase and installation of photovoltaic system & battery, wall and ceiling boarding, filling, painting, flooring, bathrooms
Preferred heating system: air-water heat pump with underfloor heating
If you have to give up some details / expansions
- Can give up: fireplace, so much space upstairs
- Cannot give up: separate apartment, large kitchen
Why has the design turned out this way?
Because this reflects our wishes, the separate apartment, and respects the development plan. We tried ourselves to design a squarer house to create space on the south side, but that didn’t work with the separate apartment.
We’re happy for you to roast the floor plan and welcome any improvement suggestions—thanks in advance.
Circled in green and oriented to north.
Sunny regards
We are a couple (both 34 years old) looking to build our home in a rural area of Baden-Württemberg. Important preliminary information: no children planned, but a dog. A separate apartment (granny flat) is mandatory with at least 23sqm (250 sq ft).
We would appreciate your input to help us avoid making major mistakes.
Development Plan / Restrictions
Plot size: 494sqm (5314 sq ft)
Slope: none
Site coverage ratio: 0.32
Edge building allowance: garage permitted
Number of parking spaces: 3
Number of stories: 2 full stories required
Roof style: gable roof with a pitch of 25–38°
Orientation: see plan
Additional requirement: separate apartment
Homeowners’ Requirements
Style: country house / modern Swedish style
Basement, floors: no basement, 2 full floors
Number of occupants, age: 2 adults (34), 1 planned dog, 1 person in separate apartment
Space requirements on ground floor and upper floor: 120sqm (1292 sq ft) for us plus at least 23sqm (250 sq ft) for the separate apartment
Office: home office, 1 person working fully from home
Guest stays per year: total about 5–15 nights
Open or closed layout: open
Open kitchen, kitchen island: open kitchen with kitchen island or U-shape preferred
Number of dining seats: 4–6
Fireplace: desired for coziness, small in size, probably not really necessary
Garage, carport: carport plus 2 additional parking spaces
Kitchen garden, greenhouse: small greenhouse plus kitchen garden
Other wishes / special features / daily routine, also reasons why certain things should or shouldn’t be: the most important space to us is the kitchen and living room combined as an open area. We want it to be cozy, which is very important. The building plot faces east on the edge of the village, with no further development planned in that direction. We really like this view, but we would also like the terrace to face south.
In general, we want to make the best possible use of the remaining garden and are looking for ideas on how to place the house on the plot to maximize garden usability. We understand the garden won’t be very large.
We both have home-centered hobbies that require space: my husband plays drums, I play piano—space needed upstairs. I enjoy baking, he enjoys cooking—space needed in the kitchen. I like to read—books require space too. We both enjoy gardening.
House Design
Designed by: architect (BU)
What do you like especially and why?
- Layout of the open space and size of the kitchen
- Location of the separate apartment
- Additional space gained upstairs. We originally considered a single-story extension for the separate apartment, but the architect said it’s more expensive than enlarging the whole house. This way, we can keep the technical room small downstairs and move the utility room completely upstairs. We would swap room usage upstairs: bedroom → utility room in the northeast, office → bedroom (this also allows a nice built-in wardrobe niche).
What do you dislike and why?
- The separate apartment has no room for a closet
- Unsure if the size of the open space is sufficient
- The bathroom is very large—like a ballroom. We considered extending the hallway to create a small extra storage room. However, this would reduce western light in the bathroom.
- We don’t like the windows and terrace doors at all yet
- Carport location: needs to be rotated and, in our opinion, moved to the boundary
Cost estimate according to architect/planner: €600,000 including secondary construction costs
Tasks we will do ourselves: roofing, purchase and installation of photovoltaic system & battery, wall and ceiling boarding, filling, painting, flooring, bathrooms
Preferred heating system: air-water heat pump with underfloor heating
If you have to give up some details / expansions
- Can give up: fireplace, so much space upstairs
- Cannot give up: separate apartment, large kitchen
Why has the design turned out this way?
Because this reflects our wishes, the separate apartment, and respects the development plan. We tried ourselves to design a squarer house to create space on the south side, but that didn’t work with the separate apartment.
We’re happy for you to roast the floor plan and welcome any improvement suggestions—thanks in advance.
Circled in green and oriented to north.
Sunny regards
DieHnnH schrieb:
So, to sum it up: our own designs are so bad that it’s not worth trying to revise them ????
Well, we gave it a shot.
What do you think was our approach? We deliberately went to the planner (not to Fjorborg) WITHOUT any prior planning and only with the room program and building permit / planning permission documents, who then forwarded it to the architect. The result is what you see on page 1. Obviously, it didn’t work out that way, hence the DIY enthusiasm.
I would have liked to send something back as feedback that fits better, so that the planner/architect can see which direction it could go.
Anyway. We are considering the next steps. Thanks to you all anyway. DieHnnH schrieb:
Thanks for the many good tips! We will compile everything and pass it on to the planner again. Alternatively, we’ll go with a freelance architect for the planning after all. No, do NOT give any feedback to THIS planner; he is obviously not qualified to process it properly (same as you, which is no shame in either case: neither laypeople nor draftspersons can replace architects). Yes, commissioning a freelance architect at least initially only for “Module A” is highly recommended from my (externally sourced) “House Construction Roadmap, also for you: the HOAI phase model” and from experience. You definitely need that, and it covers 9/98 of the total fee, so it is very affordable. A design originating only from “another layperson” is only suitable for DIY modifications within a narrow scope, such as wanting to change details. However, in this case, the planning is complicated by a mortgage in the form of the accessory dwelling unit (ADU), which is imposed by the zoning plan and the building plot allocation procedure. This weighs much heavier than a third child / second home office, a mild walking impairment, or the like. This makes the project explicitly require an architect in the professional sense, without quotation marks. And preferably not a budget offer or someone doing it on the fly (although @roteweste is quite satisfied with Frau Forster). The accessory dwelling unit — especially that ridiculous nominal version — also destroys your chance of finding an adaptable catalog design. Possibly — although no concrete example comes to mind right now — you might find a design in the depths of Kerstin’s portfolio of shelved designs.
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
@11ant Yes, I’ve already browsed your website as well 🙂
The accessory apartment is actually a tougher challenge than we initially thought.
So today, I spoke again with the head of the building department: we are now allowed to pay a penalty, although it is very much discouraged! This penalty amounts to about one-fifth of the cost for a potential accessory apartment.
PURE RELIEF is rushing through my veins right now.
The chances look good that an "adaptable draft catalog" will now be acceptable.
Otherwise, I have already gathered information from Ms. Forster and her team.
Now I just need to find "Kerstin’s portfolio of drawer layouts" and then I’ll be a happy person for this week.
I will open a new thread with the designs under the new conditions.
Wishing you all a great weekend.
The accessory apartment is actually a tougher challenge than we initially thought.
So today, I spoke again with the head of the building department: we are now allowed to pay a penalty, although it is very much discouraged! This penalty amounts to about one-fifth of the cost for a potential accessory apartment.
PURE RELIEF is rushing through my veins right now.
The chances look good that an "adaptable draft catalog" will now be acceptable.
Otherwise, I have already gathered information from Ms. Forster and her team.
Now I just need to find "Kerstin’s portfolio of drawer layouts" and then I’ll be a happy person for this week.
I will open a new thread with the designs under the new conditions.
Wishing you all a great weekend.
haydee schrieb:
Please continue this thread.
The only question is who and how the costs for a granny flat / accessory apartment are determined If this is better, feel free to use it.
I have estimated it roughly with the following assumption: 30 m² (320 ft²) x €3,300
DieHnnH schrieb:
We are now allowed to pay a penalty, even though it’s very frowned upon! This penalty amounts to about 1/5 of the cost for a potential granny flat / accessory dwelling unit. PURE RELIEF is flowing through my veins right now.It’s probably for the best 🙂
Still, last week I experimented a bit with the granny flat / accessory dwelling unit. You can get a nice house that way. However, the question remains whether the zoning group you mentioned actually exists.
Here is my quick & dirty draft:
M
MachsSelbst26 Jan 2026 23:45DieHnnH schrieb:
So today I spoke again with the head of the building department: we are now allowed to pay a penalty, even though it is strongly discouraged! This amounts to about one-fifth of the costs for a potential granny flat.
PURE RELIEF is running through my veins right now. I know, this sounds very pessimistic again... but do you have this in writing?
You plan everything now without the granny flat, you’re happy... then the head of the building department suddenly is unavailable (illness, burnout, anything can happen) and their deputy/successor says, "Uh, penalty? That doesn’t exist, without a granny flat no building permit / planning permission..."
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