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 23:07K a t j a schrieb:
Hmm, is the stove installer being objective? I’m wondering whether that closed front facing the garden is really worth it for me. It feels like a big compromise.The stove installer also has a showroom for outdoor fireplaces, but if gas is not an option from the start, that already says something. Gas fireplaces are much more common in the US and also not unusual outdoors, but even there it’s unclear whether they mostly serve for ambiance or for heating. Maybe I’ll ask about it on Reddit or somewhere.
K a t j a schrieb:
10 square meters (108 square feet) is not so cramped that a door wouldn’t fit—also opening inward. You can definitely do that.Let’s see what final furnishings we plan there. But we’ll probably rearrange rooms again anyway, partly because of potential bike noise.
K a t j a schrieb:
What seems too tight to you above, you seem to take too lightly here in my opinion. Without the scaled site plan it’s hard to judge. To me, it looks like your mother and her guests will constantly be walking right past your terrace. Five meters (16 feet) is basically nothing in a garden.That’s quite possible—I don’t really have a good sense of the distances yet. We have posts, barrier tape, and a 30-meter (98 feet) tape measure and will mark it out directly on the property so it’s easier to visualize.
If it’s too close, there simply won’t be a parking space on the plot but a path along the neighbor’s property to the entrance of the granny flat and a hedge for privacy. Parking on the street in front of the property works well, so it wouldn’t really be a loss of convenience. My mother could, of course, park in the garage upstairs if she wants to, especially in winter; a potential future tenant would then just have to use street parking.
W
wiltshire27 Jan 2025 23:24CornforthWhite schrieb:
In the USA, gas fireplaces are much more common and are not unusual in outdoor settings either, but it remains unclear whether they are mainly for ambiance or for heating purposes.In the USA, you can also buy plastic brick veneers for garden use. Gas fireplaces offer the advantage of being turned on and off with the push of a button and require less cleaning compared to wood-burning stoves. Additionally, they are low-maintenance and can be operated safely by almost anyone. I wouldn’t be surprised if gas fireplaces gradually lose market share to LED-based alternatives.
For the cozy atmosphere created by glowing embers and flickering flames as well as a physically noticeable radiant heat, you don’t actually need to buy a gas fireplace.
C
CornforthWhite27 Jan 2025 23:38wiltshire schrieb:
In the USA, you can also buy plastic brickwork imitations for the garden.
The gas fireplace offers the advantage of being turned on and off at the push of a button and requires less cleaning compared to a wood stove. It is also low-maintenance and can be operated safely by anyone. I wouldn’t be surprised if gas fireplaces gradually lose market share to LED variants.
For the cozy atmosphere of glowing embers and flickering flames, as well as the physically noticeable radiant heat, you don’t need to buy a gas fireplace. The ease of turning it on and off and the reduced mess are very strong reasons for me to prefer a gas fireplace indoors, especially in a KfW40-standard house. You also see gas fireplaces much more frequently in the UK than here, so in my opinion, it’s not just a preference of the supposedly tasteless Americans (a completely silly cliché) that Germans like to look down on. Of course, no one denies that a wood fire is even nicer.
Outdoors, a gas fireplace probably lacks the radiant heat, but there are fireplace models that compensate for this, for example, through forced convection. Whether that’s sufficient, suitable for outdoor use, and how much variety there is available in Germany, remains to be seen. I’ll wait for some advice on that. What I like about gas for outdoor use is that neighbors won’t be bothered by smoke or smell.
W
wiltshire27 Jan 2025 23:58CornforthWhite schrieb:
Gas fireplaces are much more common in the UK than here, so in my opinion it’s not just some preference of the supposedly tasteless Americans (a completely silly stereotype) that Germans like to look down on. You don’t know me—I really enjoyed living in the US and am married to an Englishwoman—and through my intercultural experience, I’m well aware of many typically German “quirks.” Still, when it comes to the casual acceptance of “fake” products, the American and also the British markets have quite a bit of—let’s put it positively—“variety” to offer.
CornforthWhite schrieb:
The advantage of being able to turn it on and off easily, plus less mess, are for me very good reasons to choose a gas fireplace, especially in a KfW40 house. That makes perfect sense. My question is this: Is the remaining benefit—thanks to the cleanliness—significant enough to justify the investment, or would it be better to skip it altogether? If the answer is “the benefit is enough,” then the decision is the right one. I have often seen gas fireplaces lead to disappointment after a short time because buyers were fooled into thinking they would deliver much of the atmosphere of a real wood fire.
I share some of the concerns that a wood stove might not be suitable for a highly insulated house (based on my experience with three wood stoves in the house), but I also see the opposite. A masonry stove works perfectly with a high energy standard because its heat output curve is quite gentle. In contrast, a metal wood stove produces a large heat spike over a very short time, which can sometimes be too much and lead to opening windows in winter, which may feel pleasant but is energetically wasteful.
C
CornforthWhite28 Jan 2025 00:24wiltshire schrieb:
You don’t know me – I really enjoyed living in the USA and I’m married to an English woman – plus I have enough intercultural experience to understand many typically German "quirks." However, when it comes to the cheerful, unsuspecting approach to "fake" products, the American and also the English markets are definitely – to put it positively – a bit more "diverse" than ours.That’s true – for me, the "highlight" are the unfortunately not so rare plastic lawns, which, as far as I know, I thankfully haven’t seen in Germany yet. But as always, it’s very much a question of education and social background rather than nationality. Still, I find the "cheerful, unsuspecting approach to ‘fake’ products" (nicely put!) arguably more likeable than a perhaps typically German sour-faced lack of fun about these topics.
wiltshire schrieb:
That’s totally understandable. The question I have is this: Is the remaining functional benefit after cleaning really big enough to justify the investment, or would it be better to skip it altogether? If this question can be answered with "benefit is sufficient," then the decision is right. I have often seen that gas fireplaces caused disappointment after a short time because buyers were deceived into thinking that a gas fireplace could largely provide the atmosphere of a wood fire.
Regarding the concern that a wood stove might not fit well into a very well-insulated house, from my experience (three wood stoves in the house) I can both agree and disagree. A masonry stove fits perfectly with a high energy standard because its heat output curve is quite gradual. On the other hand, a metal stove produces a large heat wave in a very short time, which can sometimes be too much and lead to opening windows in winter—which is pleasant but energetic madness.For me, cleanliness is more of a nice side effect (I am definitely not a cleaning fanatic); my concern was more that it might become too warm and then you’d simply turn the gas fireplace off. Visually, I mainly want a nice (preferably antique) mantelpiece because it’s incredibly decorative. Additionally, I’d like some visible flames and of course some heat. Ideally, the look of an open fireplace behind the mandatory glass panel. In my flat in London, I had a beautiful mantelpiece and used to put candles in the no-longer-functional fireplace. Also pretty, but of course not quite what you want. Still, that would probably be the most likely alternative if we decide that gas fireplaces don’t suit us after all.
W
wiltshire28 Jan 2025 00:39CornforthWhite schrieb:
Nevertheless, I find the "cheerfully naïve approach to 'fake' products" (nicely put!) more likeable than a typically German sour-faced seriousness when it comes to these topics. 100% agree!
CornforthWhite schrieb:
Visually, I especially want a nice (preferably antique) mantelpiece because it’s simply incredibly decorative. We had one in our terraced house—in the Netherlands and Belgium, during the 19th century there was a trend to replicate the grand stone surrounds in wood. We bought one exactly for the decorative reason you mentioned, on a whim, at an antique shop in s’Hertogenbosch, and kept it for years in the living room of our terraced house. I dug up a photo of that piece from Christmas 2016/17. For scale: the tiles are 33cm (13 inches) square, and the speakers are just over 90cm (35 inches) tall.