Floor plan for a multi-generational house on a demanding plot

Hello everyone,

Currently, I am considering building a multi-generational house together with my parents. There is a plot of land available (approx. 700m²) in a location that we really like, but the shape of the plot is not ordinary and presents me with one or the other challenge regarding the rough planning.

I hope to get some ideas from you that will take me in completely different directions. I keep coming back to the same solution (I have included a very rough draft below): From the street view: single-family house + garage on the right side and at the back the "granny flat" as an extension.

We have already had several discussions with my parents and know what our ideas for a solution are. Fortunately, there is no pressure or compulsion behind this plan that it absolutely has to work with an additional apartment. However, we could well imagine it if these parameters are met:

[*]separate entrances on different sides of the house
[*]terrace of the single-family house and terrace of the granny flat are not directly adjacent; preferably apart or "around the corner"
[*]windows of main living areas (living room; kitchen etc.) are not directed towards the other’s garden

This should not be understood as meaning that we do not want to know about or see each other. We are already living together under one roof without any problems. However, we would like to implement the points mentioned above. Also, so that in a few decades the granny flat could possibly be rented out to "strangers."

The rough draft practically envisions a classic single-family house with a single garage. Kitchen and living room on the south/west side facing the garden.
An extension (only ground floor, possibly flat roof) is connected behind the garage, partially overlapping with the single-family house. The living/cooking area is in the northern part with the possibility to place a terrace in the intended recess (to keep the approx. 3m limit). Bedroom in the area of the wall to the garage; bathroom practically below the dimension labeled "9.5m."

What I like about this draft:

[*]structurally and spatially separated; from the street, the extension would hardly be visible; still visually a "normal" single-family house
[*]separate living areas in the garden
[*]possibility to drive with the car past the left side of the single-family house into the garden (especially with a trailer for gardening work etc.)

What I do not like:

[*]I struggle a bit with my conscience not to provide my parents with truly south/west-facing windows with this draft
[*]the described bathroom with existing window would look directly into our garden

I look forward to further ideas. Also, completely different approaches are welcome; as I said, I fear I am already somewhat "blind." I hope this "draft stage" is okay – I have not yet dared to start planning the interior as long as the rough structure is not yet satisfactory.

I hope this "draft stage" is okay - I haven't even dared to plan the interior as long as the rough structure is not yet satisfactory.

The rough structure will and must change, since the open floor plan usually dictates the framework of the floor area. As far as I know, due to fire protection regulations, windows of residential units must be at least 3 meters apart, meaning they are not allowed to be arranged around corners; your floor plan will have to suffer in terms of window placement - either the main house in the west or the granny flat in the southwest. Since you are practically combining the units, thus clustering them, you lose valuable window area in both units. At that point, you might as well build a duplex with more structure and equal conditions for the terrace and so on, namely with a southwest orientation, one with a garage all the way in the back, the other at the front. The granny flat part smaller. I would first try to ensure the garage gets edge development. Between the house and garage there can be a courtyard from which the granny flat can be accessed. Or you place the granny flat upfront and have parking spaces in the back. What does the development plan say about the floor space index, etc.?

Your willingness to discuss does not bring you to a solution nor is it the purpose of a forum. You have to say something at least :)

@MidnightBlack
Your willingness to discuss does not lead you to a solution nor is it the purpose of a forum. You have to at least say beep :)

Well, it can also take a bit longer until the beep, I think


To the point:
In principle, I find an arrangement with as much privacy as possible for both parties a good idea. The arrangement you have drawn will, as mentioned, cause problems either during the approval phase or later in the rental (in Cologne, even apartments with pure north orientation may not be rented out, even if they are quite bright due to a large window front...)

The first thing that comes to mind is the arrangement in a staggered, asymmetrical semi-detached house ("half" is simply smaller).

Are there differences in elevation on the site that could be used? Three-dimensionality offers further possibilities to create privacy.

Also, the idea of a small penthouse with a roof garden on a bungalow occurred to me. This will hardly be cost-effective to realize.

Well, I think it can take a bit longer until the beep sometimes

Yes, but he still has his first question in this forum open, which he has not followed up on. And if you are already visibly "active" here, then you can also maintain your own threads. The OP is reading along, is logged in multiple times after posts, just does not participate in any discussion. I wouldn't say anything if such behavior was not noticeable.

Hello,

As far as I know, due to fire protection regulations, windows of residential units must be 3 meters apart, meaning they are not allowed to be placed around a corner, so your floor plan will have to suffer in terms of window placement—either the main house in the west or the granny flat in the southwest.

Ok, I didn’t have that in mind either. When I created the concept, I had this floor plan in mind, for example: ProGeneration 132-47/20 from fertighaus.de (I don’t think external links are allowed here?). I actually didn’t consider corner windows. A 3-meter distance between them would definitely be possible.

Since you are basically combining the units, i.e., clustering them, you lose valuable window area in both units. Then you could basically build a semi-detached house with more structure and equal conditions for terrace etc., namely with southwest orientation, one garage at the very back, the other one in front. Granny flat part smaller.

Yes, that’s true. Exactly that is causing me some difficulties. We specifically do not want to build a semi-detached house. On the one hand, everything for the smaller apartment should be on the ground floor if possible. On the other hand, “classic semi-detached houses” do not appeal to us at all. I also don’t find the option of building a “real” granny flat that, for example, is fully integrated on the ground floor and the upper floor fully belongs to the “main house” optimal, since we want to have as much of the living space as possible on the ground floor. Therefore, the basic approach is towards “two building volumes that have an overlap.”

What does the development plan say about the site coverage ratio etc.?

The site coverage ratio is 0.4—we could play around a bit with the plot size though.

Your willingness to discuss neither brings you to a solution nor is it the purpose of a forum. You have to say something first :)

Yes, that’s true. I have read your answers here but haven’t yet had the opportunity to respond appropriately. Regarding my other thread: I was very grateful for the initial assessments as well. However, the financing topic is currently difficult to address if it’s not yet clear whether a single-family house or a single-family house + “granny flat” will be built. That definitely changes the investment framework :)

First, what comes to mind is the arrangement in an offset asymmetric semi-detached house (one “half” is simply smaller).

Is the sentence not complete? Do you notice anything / do you like something or is that a suggestion? ;-)

Are there any height differences on the site that could be used? A three-dimensionality offers further possibilities to create privacy.

No, there are no height differences.

Are there any other possible solutions or floor plans that could serve as an idea pool?