ᐅ Floor Plan Design for a Single-Family Home of Approximately 250 sqm with a Separate Granny Flat
Created on: 26 Jan 2025 21:52
C
CornforthWhite
I already feel a bit anxious writing this, anticipating the inevitable criticism of our design, but I’m posting it anyway. We struggled somewhat with the software, so much of the presentation is still quite provisional. Our main goal is to find out whether what we’ve basically planned could work. We’re primarily looking for feedback on functional planning errors. Style critique is sure to come since our design is unlikely to suit most people’s taste here—but that interests us less (we like what we like, and that probably won’t change). Although tastes vary, I’ve learned a lot from other threads recently and hope that “the usual suspects” might also take a look at our design. Thanks in advance!
Development Plan / Restrictions
Plot size: 960 m² (10,333 sq ft)
Slope: no
Floor area ratio: 0.2, maximum buildable footprint however <175 m² (1,883 sq ft)
BUT: the 1977 Building Use Ordinance applies
Floor space index: -
Building envelope, building line and boundary: 5 m (16 ft) from the road on the south and west, 3 m (10 ft) from neighbors on the north and east
Edge development: no
Number of parking spaces: 1.5 per dwelling unit
Number of storeys: 1 + attic
Roof style: no fixed style, but roof pitch regulation with 2 options
Option 1: 22–26 degrees
Option 2: 33–44 degrees
Architectural style: no specification
Orientation: flexible
Maximum heights / limits: in red the official restrictions of the development plan, in green the generously granted exceptions we are aware of (several times approved). The neighbors recently submitted a building application aiming for slightly higher eaves and knee wall heights—this will serve as a reference for us.
For roof option 1 (22–26 degrees pitch): ridge height max. 8 m (26 ft) (or 8.15 m / 27 ft), eaves height max. 4.0 m (13 ft) (or 5.20–5.30 m / 17–17.5 ft), knee wall max. 115 cm (45 in) (or 2.20–2.30 m / 7–7.5 ft)
For roof option 2 (33–44 degrees pitch): ridge height max. 10.5 m (34 ft), eaves height max. 3.5 m (11.5 ft), knee wall max. 40 cm (16 in) (exceptions probably possible but no figures known)
Definition of eaves height: Top of rough ground floor slab to intersection of exterior wall with the bottom edge of the rafters
Definition of knee wall: Top of rough attic floor slab to intersection of exterior wall with the bottom edge of the rafters
Client Requirements
Architectural style, roof shape, building type: a new build that does not look like a typical new build
Basement, floors: no basement (high groundwater level, no living space planned underground), two full stories (which are effectively possible due to generous exceptions from the development plan)
Number of people, age: my mother (70+), my husband and I (late 30s), 2 cats, 1 dog, 1 child planned
Space requirements on ground and upper floors: On the ground floor a self-contained apartment for my mother and kitchen / living / dining / utility for us;
Office: 2 offices (both approx. 50% and 80% remote work)
Guest stays per year: about 2–3 weeks
Open or closed layout: open on the ground floor
Conservative or modern building style: conservative
Open kitchen, kitchen island: yes to both
Number of dining seats: 6–8
Fireplace: yes (gas fireplace)
Music/sound system wall: no
Balcony, roof terrace: balcony would be nice
Garage, carport: spacious double garage
Utility garden, greenhouse: rather no
Other wishes / special features / daily routine, including reasons why some things are desired or not:
House Design
Who designed it: DIY
What do you like most and why?
- Style inspired by classic American Colonial architecture
- Living area centered around the fireplace
- Porch with insect protection, fireplace & privacy
- Kitchen island with plenty of workspace
- Small “secondary kitchen” to temporarily hide dirty dishes / cooking mess
What do you not like? Why?
I wouldn’t exactly say “dislike,” but we have doubts about the following points:
Personal price limit for the house, including fittings: we’re budgeting €3,000 per m² plus additional costs and landscaping, but have significant equity and thus some flexibility upwards; also plan a lot of personal work.
Preferred heating technology: heat pump with geothermal probe
If you have to give up something, which features/finishes
- Could be sacrificed: balcony
- Cannot be sacrificed: no compromises on the self-contained apartment
Why is the design like it is now?
We originally wanted to buy a house with old-style charm but found nothing suitable. Although we like modern, minimalist architecture, it’s not for us personally.
I’ll help a bit with the images.
Development Plan / Restrictions
Plot size: 960 m² (10,333 sq ft)
Slope: no
Floor area ratio: 0.2, maximum buildable footprint however <175 m² (1,883 sq ft)
BUT: the 1977 Building Use Ordinance applies
- § 19 IV: Ancillary structures according to § 14 are not counted towards the allowable footprint. The same applies to balconies, loggias, terraces, and structural elements as far as they are permitted within setback areas or distance zones under regional law (here: Bavaria) (…).
- § 21a III: Covered parking spaces and garages are not to be counted towards the allowable footprint as long as they are less than 0.1 of the plot area.
Floor space index: -
Building envelope, building line and boundary: 5 m (16 ft) from the road on the south and west, 3 m (10 ft) from neighbors on the north and east
Edge development: no
Number of parking spaces: 1.5 per dwelling unit
Number of storeys: 1 + attic
Roof style: no fixed style, but roof pitch regulation with 2 options
Option 1: 22–26 degrees
Option 2: 33–44 degrees
Architectural style: no specification
Orientation: flexible
Maximum heights / limits: in red the official restrictions of the development plan, in green the generously granted exceptions we are aware of (several times approved). The neighbors recently submitted a building application aiming for slightly higher eaves and knee wall heights—this will serve as a reference for us.
For roof option 1 (22–26 degrees pitch): ridge height max. 8 m (26 ft) (or 8.15 m / 27 ft), eaves height max. 4.0 m (13 ft) (or 5.20–5.30 m / 17–17.5 ft), knee wall max. 115 cm (45 in) (or 2.20–2.30 m / 7–7.5 ft)
For roof option 2 (33–44 degrees pitch): ridge height max. 10.5 m (34 ft), eaves height max. 3.5 m (11.5 ft), knee wall max. 40 cm (16 in) (exceptions probably possible but no figures known)
Definition of eaves height: Top of rough ground floor slab to intersection of exterior wall with the bottom edge of the rafters
Definition of knee wall: Top of rough attic floor slab to intersection of exterior wall with the bottom edge of the rafters
Client Requirements
Architectural style, roof shape, building type: a new build that does not look like a typical new build
Basement, floors: no basement (high groundwater level, no living space planned underground), two full stories (which are effectively possible due to generous exceptions from the development plan)
Number of people, age: my mother (70+), my husband and I (late 30s), 2 cats, 1 dog, 1 child planned
Space requirements on ground and upper floors: On the ground floor a self-contained apartment for my mother and kitchen / living / dining / utility for us;
Office: 2 offices (both approx. 50% and 80% remote work)
Guest stays per year: about 2–3 weeks
Open or closed layout: open on the ground floor
Conservative or modern building style: conservative
Open kitchen, kitchen island: yes to both
Number of dining seats: 6–8
Fireplace: yes (gas fireplace)
Music/sound system wall: no
Balcony, roof terrace: balcony would be nice
Garage, carport: spacious double garage
Utility garden, greenhouse: rather no
Other wishes / special features / daily routine, including reasons why some things are desired or not:
- Covered terrace / loggia / outdoor seating with reliable but as discreet as possible insect protection (lakeside location, regular mosquito issue) & fireplace (probably gas as well)
- A rather unpopular opinion here, but we explicitly do not want roller shutters or venetian blinds. We currently have them despite many south-facing windows and never use them (feels like a vault). Instead, we plan air conditioning (powered by photovoltaics) and larger trees.
- Gas stove (I just can’t get comfortable with induction)
- Washing machine & dryer on the upper floor
- In one office, a small niche for an exercise bike (turbo trainer)
House Design
Who designed it: DIY
What do you like most and why?
- Style inspired by classic American Colonial architecture
- Living area centered around the fireplace
- Porch with insect protection, fireplace & privacy
- Kitchen island with plenty of workspace
- Small “secondary kitchen” to temporarily hide dirty dishes / cooking mess
What do you not like? Why?
I wouldn’t exactly say “dislike,” but we have doubts about the following points:
- Passage between garage and house might be too narrow?
- Entrance and staircase possibly not spacious enough?
- Staircase: can’t properly design it in the software, but according to a stair calculation tool it should work. Is the space requirement adequate? Are the asymmetrical runs a problem?
- Bedroom in the self-contained apartment is borderline small
- Bathrooms: enough space?
- Utility/technical room: large enough?
- Could a mechanical ventilation system with heat recovery possibly be installed in the crawl space attic?
Personal price limit for the house, including fittings: we’re budgeting €3,000 per m² plus additional costs and landscaping, but have significant equity and thus some flexibility upwards; also plan a lot of personal work.
Preferred heating technology: heat pump with geothermal probe
If you have to give up something, which features/finishes
- Could be sacrificed: balcony
- Cannot be sacrificed: no compromises on the self-contained apartment
Why is the design like it is now?
We originally wanted to buy a house with old-style charm but found nothing suitable. Although we like modern, minimalist architecture, it’s not for us personally.
I’ll help a bit with the images.
C
CornforthWhite27 Jan 2025 20:49haydee schrieb:
Have you ever heard of the ergonomic triangle in the kitchen? I’m gradually losing track of what exactly you want to do in each kitchen.I want to use the secondary kitchen to quickly move dirty dishes out of sight from the main kitchen (that’s why there is a second sink there). Also, the dishwasher will be placed there because my husband unfortunately has a very sensitive nose and might want to close the door against potential “dishwasher smell.” Immediately to the right of the door, there will be a refrigerator-freezer combo, since many refrigerators start making noise as they get older, and having the freezer on tile rather than hardwood is also practical for defrosting. This is not fully or clearly shown in the floor plan yet, as we didn’t want to get bogged down in all the details in case larger changes need to be made elsewhere.
Everything else should happen in the main kitchen. I find the distance between stove, sink, and refrigerator acceptable with this layout. The refrigerator would probably be more convenient in another location, but if you want the fridge in a separate room at the same time, I don’t see how else it could be solved (but I’m happy to hear suggestions).
haydee schrieb:
Upper floor – the route between children’s room and bathroomFrom our point of view, there are two possible solutions here. Either the children’s room could be moved to the northeast corner and would then be directly opposite the bathroom. The room has three relatively large windows, so hopefully it will be bright enough despite the orientation, but it would still be located above the (eventually rented) apartment, which was previously viewed critically here. The office with the bicycle would then be next to the walk-in closet and the other office in the southeast corner.
Alternatively, in an earlier draft, the second bathroom on the upper floor was on the east side, directly above the apartment’s bathroom and thus also right next to the children’s room. We didn’t like this option for other reasons, but I can look it up for comparison and post it here.
haydee schrieb:
The awkward corner in the children’s room due to the bicycle in the study.Actually, I found it quite cozy, as it creates a somewhat sheltered niche for the desk in the children’s room. But if we swap or move rooms again, this will be redesigned anyway.
haydee schrieb:
I miss natural light in the master bathroom, and the shower is placed very close to the toilet.The master bathroom could possibly get an additional window on the north wall. I still need to figure out how to arrange the shower. The shower will have a door, it just hasn’t been shown in the drawings yet. From your perspective, is having wet feet still an issue? Or do you think the overall distance is too tight?
Make the kitchen fully enclosed, and if needed, include a coffee station or a small kitchen counter area open to the living space.
I find the space between the shower and the toilet too narrow. You are designing a very large house, so narrow spots can be avoided. This is not an 80m² (860 sq ft) apartment.
I find the space between the shower and the toilet too narrow. You are designing a very large house, so narrow spots can be avoided. This is not an 80m² (860 sq ft) apartment.
CornforthWhite schrieb:
Floor-to-floor height: 3050 mm (120 inches)
Stair flight 1: 1679 mm (66 inches) = 2320
Stair flight 2: 2682 mm (106 inches) = 2330
Stair flight 3: 2437 mm (96 inches) = 2320
Tread width: 100 mm (4 inches)
Number of steps: 16
Number of risers: 17
Riser height: 179 mm (7 inches)
Tread depth: 273 mm (11 inches)
Angle: 33.31 degrees
Blondel’s formula: 631 mm (25 inches) I’ll add my input here
I think your riser heights and tread depths are appropriate. I’m just not sure if the distribution of the stair flights works well. Compare this to a floor-to-floor height of 280 cm (110 inches) with one step less in the red marked area. Also, looking at your staircase, I am concerned about the red highlighted section. There are 5 to 6 steps tapering sharply toward the center due to uneven distribution of the flights. But I’m not a professional stair builder.
C
CornforthWhite27 Jan 2025 21:38K a t j a schrieb:
Hi, I’d like to add my two cents as well.
First of all, hats off for the planning. I think the whole thing looks quite nice, provided the municipality actually approves the knee wall.Thank you. The municipality and the district authority have already approved a knee wall height of 2.30m (7 ft 7 in) several times, and once even 2.39m (7 ft 10 in), so that should work out.
K a t j a schrieb:
Here’s what really bothers me:
- The fireplace including the chimney is in the wrong place. On the one hand, it blocks the view and the exit to the terrace – which is really unfortunate. On the other hand, this thin chimney runs up the exterior wall, which looks awful. Can’t it be moved to the right side wall of the living room? Unfortunately, it’s not clear how close the walls are to each other.
- Basically, “back to back” with the living room fireplace, we want another fireplace on the terrace. Both flues would be concealed behind a brick cladding that looks like a chimney. We saw this in a house previously and thought it looked really good – or at least we like it very much. Unfortunately, I can’t share a picture here due to image rights. The chimney looks ugly in our drawing, I agree, but in the actual example it looks much better. We’re still unsure whether a gas fireplace on the terrace will generate enough heat to extend the “terrace season” or if it will just be a “mood fire.” We have a consultation scheduled soon with a stove builder to clarify this. If we decide to drop the terrace fireplace, we would arrange the flue/chimney for the living room fireplace differently.
- I think the dining area is quite tight. But you don’t entertain guests much anyway.
- It feels like the lounge area and dining room should be swapped – but I’m not sure.
- That “bike closet” is ridiculous. Why can’t it be in the office? That awkward extension would be gone immediately, leaving two nice, rectangular rooms.
- I would move the bedroom door forward to the dressing room. That would create a calmer hallway and keep the clothes out of immediate sight.
- Sliding door in the small office? Why?
- Regarding the granny flat – have you already discussed it with your mom? I think it’s okay, but she might have other priorities. Does she really need five dining seats?
- The driveway to the granny flat seems to run across your terrace. I see that as a major drawback and would probably make me rethink everything. And if five guests were to come – oh dear!
K a t j a schrieb:Actually, we regularly have selected guests we really like, but mostly not large groups. The current table size is 180x90cm (71 x 35 in), but I already mentioned that I find the dining area a bit small, and we want to try to enlarge it somewhat. Some minor exceedances in floor area ratio have already been approved, or we may have to save space elsewhere.
K a t j a schrieb:Sofas in the brightest and sunniest room of the house would probably not be our style.
K a t j a schrieb:The current bike closet might not be the optimal solution yet, but the bike should not be in the office. My husband has had various indoor trainers in the office for over 10 years, and he explicitly doesn’t want that anymore. It looks ugly and messy, and it’s not good for video conferences.
K a t j a schrieb:We had that layout before and changed it because we preferred a longer hall and hope the clothes will be stored in nice built-in wardrobes, making the dressing room visually appealing and not a problem. But maybe that’s too optimistic, and we should move the door back as you suggested.
K a t j a schrieb:Because due to very limited space, the door should at least not open inward, and we were unsure if opening outward into the hallway would be a good idea.
K a t j a schrieb:My mother generally likes the granny flat. We haven’t specifically talked about the dining table yet, but I know her well enough to know that having a table of reasonable size is a must for her. Not only to entertain guests but also in everyday life for papers, flowers, coffee table books, etc.
K a t j a schrieb:I really don’t understand that right now. Maybe there’s a misunderstanding? I’ve marked the parking space for the granny flat on the site plan. The path to the granny flat entrance would run along the neighbor’s fence. We’d possibly plant privacy screening on the left side towards our terrace.
This brings me to the next point:
K a t j a schrieb:
I’m also missing dimensions and preferably a 2D site plan.
2D site plan? Do you mean a satellite image?[/QUOTE]
K a t j a schrieb:
Finally, why don’t you let a professional plan the whole thing? Did you just want to experiment, or are you worried the architect won’t put in enough effort?
On one hand, we wanted to try it ourselves. On the other hand, we don’t like much of what professionals are currently designing. To some extent, we see the challenge in finding someone who would implement our style or who has already done similar projects. Patrick Ahearn and Sebastian Treese are unfortunately beyond our budget.
C
CornforthWhite27 Jan 2025 21:48kbt09 schrieb:
I’ll add this here
I think your risers and treads work. I’m just not sure if the distribution of the flights is ideal. See the comparison with a floor height of 280 cm (110 inches) with one step less marked in red. And then, from your staircase, the area I find problematic marked in red: 5 to 6 steps that converge too tightly in the middle due to the uneven leg distribution. I’m not a staircase builder, though.
As mentioned, the drawing we have is just a placeholder and not accurate. The tool doesn’t handle spiral stairs well and unfortunately produces incorrect layouts. In the staircase tool’s sketch, the steps don’t converge as sharply in the middle. As I don’t have image rights, I can’t share that sketch here.
haydee schrieb:
Just make it a closed kitchen, and if needed, add a coffee station or kitchenette in the living area. Since I’m the one cooking 90% of the time, I have to veto that. A closed kitchen would only be an option if it’s quite large and open to the living area, but honestly, I’m tired of being alone in the kitchen.
haydee schrieb:
I find the space between the shower and toilet too narrow. You’re planning a very large house, so tight spots can be avoided. This isn’t an 80 sqm (860 sq ft) apartment. That’s true. We’ve already changed this bathroom layout around 20 times, but it probably still needs some optimization. The floor plan currently has an issue from the recent changes to the exterior view (bathroom exterior wall in front of the washing machine) – please just ignore that for now.
CornforthWhite schrieb:
but just because we didn’t revise everything within 24 hours doesn’t mean I should be considered resistant to advice. No one here expects that. No one expects you to implement anything. You’re not building a house for any of the responders. You are building your house the way you like and want it.
But maybe you should take another look at everything, focusing on your own replies. Psychologically trained people are gently suggesting that the accessory apartment might be a bit narrow, and you respond with a counter-question, “Really?” and compare it to an old apartment. I mean: the accessory apartment is no more than 4 meters (13 feet) wide.
CornforthWhite schrieb:
Do you think the bathrooms are too small overall? We are definitely not “wellness types” who value a large bathroom retreat or spend hours there, but of course we don’t want to build a relatively large house and then plan bathrooms that are too small. CornforthWhite schrieb:
... I see it differently when it comes to the bathroom. We’ve had a bathroom with almost identical dimensions before, and it was absolutely fine. This is another contradiction and comparison. And yes: it is perfectly valid to make comparisons.
CornforthWhite schrieb:
I asked where exactly you see problem areas, but then there was no further answer. Exactly. If you approve everything and consider it already experienced and sufficient, what else is there to explain? There’s no “part two” from me because your argumentation leaves no room for it, and to respond more precisely, measurements are needed—which haven’t been provided.
I also don’t want to spend time measuring via scaling.
In addition, you stated that you don’t really want to change much anymore. So I won’t keep focusing on the toilet that feels cramped next to the shower or the bathroom in the accessory apartment, which I wouldn’t even plan at that size for children.
But I’m completely fine with this and will continue to follow the discussion.
Edit: I understand the single-story design is approved due to the two extensions.
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