ᐅ Detailed Floor Plan for a Single-Family Home with Basement and Separate Apartment

Hello everyone,

I would like to get some crowd wisdom on our floor plan (I have already shared it here before regarding a specific detail and an earlier version – see here, but at that time the main focus was on the separation between garage and house).

A quick heads up, since this has been discussed before: unfortunately, the floor plans for the ground floor (GF) and upper floor (UF) are set in stone — they are part of a standard house model from a prefab house manufacturer that cannot be altered (or can, but not within our budget). So, feel free to give harsh criticism on those, but we probably won’t be able to make changes. We believe the floor plan fits our wishes and needs well.

Where we do have some flexibility is in the basement level, which we have to build separately under individual contracts.

There, we have some leeway within certain limits, and this is where my main questions are:

• In the basement’s separate apartment living area, I’m unsure whether to locate the kitchen in the southeast corner (as currently suggested in the plans) or rather in the northwest, where the sofa is shown now. I could weigh up the pros and cons of both options...
• Compared to the current plan, I have decided to combine the two windows on the apartment’s south side into one large wide lift-and-slide door. Now I’m hesitating whether it might make sense to extend the ground floor roof terrace with a balcony of about 1 meter (3 feet) towards the south, so it would act as a small canopy over the basement window front. I’d like to install the lift-and-slide door as close to flush with the floor as possible and am somewhat concerned about precipitation. However, that would mean integrating it into the facade with a thermal break (Isokorb), which of course would be a bit more costly.
• I’m also not very happy with the bathroom layout in the apartment, but I don’t yet have any striking ideas on how to improve it. One requirement is that the bathroom be as age- and disability-friendly as possible — not necessarily to meet any specific standards, but to make it as practical as possible for such users (or for us in a few decades…).
• Recently – and this relates more to garden design – I’ve been unsure whether to plan light wells on the west side in front of the living/dining area and bedroom windows (as currently shown), or instead run a pathway around the house that goes just under the window sill height (around -30 cm (1 foot)) and compensate for the height differences with steps…

Compared to the current version of the plans, I should add that all below-ground walls in the basement (west, north, and east/garage sides) will be built with 28 cm (11 inches) thick waterproof concrete, not 24 cm (9.5 inches) as currently shown. This means we will lose some space (we essentially have to move them slightly inward). Also, due to a somewhat lax approach to detailing by the architect, we need to raise the basement ceiling under the ground floor walls by +10 cm (4 inches) to align with the floor-to-door height of the ground floor balcony doors. I will take this opportunity to install a suspended ceiling in the basement to accommodate most of the utility lines there.

By the way, the site plan is oriented with north at the top, while the others are slightly rotated, but effectively north is still upwards.

For completeness, I have also filled out the questionnaire.


Development plan / restrictions
Plot size: 1018 sqm (10956 sq ft)
Slope: yes
Floor area ratio: no restrictions
Floor space index: no restrictions
Building envelope, building line, boundary: as in site plan
Adjacent buildings: no
Number of parking spaces: 2
Number of floors: no restrictions, according to surrounding buildings
Roof style: -
Architectural style: -
Orientation: -
Maximum heights / limits: -
Other requirements: retention cistern, fully biological small sewage treatment plant

Client requirements
Architectural style, roof style, building type: gable roof, rather classic
Basement, floors: basement + ground floor + upper floor
Number of people, age: 2 adults in early 40s, 2 small children, possibly 1 or 2 retirees in the separate apartment
Space requirements on ground and upper floors: as planned
Office, family use or home office?: possibly, if the apartment is not used as intended
Number of overnight guests per year: 10 to 20 (as long as apartment remains a guest unit)
Open or closed architecture: open
Conservative or modern construction: mixed
Open kitchen, kitchen island: open kitchen, peninsula
Number of dining seats: 6
Fireplace: no
Music/sound wall: no
Balcony, roof terrace: yes
Garage, carport: garage, integrated in basement
Utility garden, greenhouse: no
Special features: KfW 55 standard

House design
Planning by: architect for basement, prefab house manufacturer for ground and upper floors
What do you like most? Why? Utilization of limited building envelope and plot width
What don’t you like? Why? see questions
Cost estimate by architect/planner: not relevant
Personal price limit for house including fittings: not relevant
Preferred heating technology: brine-to-water heat pump

If you had to forgo anything, which details/extensions
- could be omitted: green roof on garage, possibly garage
- cannot be omitted: separate apartment

Why is the design the way it is now? For example:
Mixed standard design + individual/architect planning, largely implemented as desired.


Many thanks in advance for your help!

Harakiri schrieb:

However, we still have some flexibility in the basement, which we are allowed (and required) to build separately through individual contracts.

A shell construction (OKKD) is a crucial interface. I strongly advise against making the basement your own responsibility as the client – to put it less poetically, you should categorically refuse to act as the principal contractor for the basement yourself!

1. The kitchen is more cost-effective in the planned location compared to the ground floor’s kitchen.
2. This will cost an unreasonable amount and won’t be properly effective in the secondary apartment.
3. The bathroom is fine and, for this apartment, on the borderline of being more than adequately sized; overall, it’s more than sufficient. Forget the idea of a separate apartment for elderly use. Your own remaining statistical life expectancy is longer than the declining trend of such arrangements. I already see stocks of stairlift manufacturers turning into penny stocks by 2040 ;-)
4. That sounds like a promising alternative.

---

https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/

Harakiri schrieb:

I wanted to get some collective intelligence to take a look at our floor plan.

Harakiri schrieb:

Unfortunately, the floor plans for the ground floor and upper floor are already finalized in stone or wood.

What was the question again? What are you looking for from the forum?

Your budget is limited, so changing the standard house design is not possible. What is the purpose of the costly granny flat / accessory dwelling unit? Guests can stay at a hotel for the ongoing costs of the granny flat. The granny flat is not suitable for people with disabilities.

@11ant: Thanks for the tips and comments. You’re probably right about contracting separately; unfortunately, with this house manufacturer, building permits/planning permission or the basement including excavation always have to be commissioned separately. They never do it any other way. Well, it will probably get "interesting" here and there.

@ypg: As I mentioned before, I would appreciate feedback regarding the basement, specifically on my questions, but also in general – in theory, we can still redesign everything (except for the stairwell and within reasonable structural limits).

@haydee: Our plan is as follows: for the next 3 to 5 years, it should serve as a guest apartment because my parents live many thousands of kilometers away – they would like to visit the children 3-4 times a year for longer stays (about 2-3 weeks each time). Afterwards, our parents-in-law will move in as soon as they are no longer able to maintain their own home. Later on, we can very well imagine living there ourselves if one of the children wants to occupy the house – we find the idea of a multi-generational home quite appealing. As a backup plan, we could also rent it out if absolutely necessary financially (which we hope to avoid). It should not (hopefully) need to be fully accessible for people with disabilities, but it should be as age-appropriate as possible. What else do you think should be taken into consideration?

I’ll start with the upper part. If, instead of the double casement window in the stairwell, you install a window in the wall and extend it downwards, you will also get natural light into the basement.

Who is responsible for the detailed design or construction planning? Is it one person handling everything or two? The terrace reminds me of the rooftop terrace of the “Räuber” house, which had a step because they forgot that the floor structure inside the house is at a different height than outside. Where do your utility lines enter the basement?