Floor plan, house layout EFW 150m2, basement + granny flat - feedback desired

Hello dear forum,

we have been quietly reading along for some time, knowing that we will eventually build ourselves. Thanks in advance to everyone who posts regularly here and shares their knowledge. This is super helpful for laypeople like us. We are already grateful that you are dedicating yourselves to our project and looking at it critically. It is getting closer now. The plot is available. It is located near a landscape conservation area with a slight slope. The soil survey occasionally indicates pressing water.

How do we proceed?

[*]Buy plot, conduct soil survey
[*]Align and plan house on plot with architect (phases 1-3)
[*]Tender to general contractor and individual trades for interior construction with subsequent comparison
[*]Construction with expert supervision

What do we want to build?

[*]Single-family house + granny flat (for family and for tax reasons, primarily because of all the depreciation possibilities and therefore also with QNG)
[*]Why the basement? Maximize garden area, take storage space, "apparently" utilize the slope

Development plan/restrictions
Plot size: 650m2
Slope: Yes, slight (scale 1:250 see heights in annex, 1m over almost 10x11m)
Floor area ratio: no development plan, no formal requirement, about 220sqm footprint possible after consultation with building authority
Floor space index: no development plan, about 220sqm footprint possible
Building window, building line and boundary:
- 5m to street
- 3m to neighboring buildings
Edge development: On the sides and opposite on the street;
Number of parking spaces: probably 3 needed (could place the house further back so that these are directly in front of the house)
Number of floors:
- technically 2,
- but should be visually adapted to surrounding buildings and therefore have a 1.5-storey look
Roof shape: Gable roof, 30-40cm overhang
Style: Modern
Orientation: SE, but with a lot of historic tree stock all around from east to west at the property boundary
Maximum heights/limits: Neighboring buildings, see street layout
Further requirements: For flat roof, 1m setback to the street and on the sides

Owners’ requirements
Style: Modern
Roof shape:
- Gable roof between 25-33°
- Originally flat roof due to neighbor on the left, now mainly gable roof because of budget, maintenance and the required setbacks
Building type: Single-family house + granny flat
Basement: Yes
Floors: "1.5"
Knee wall height: 1.90m (no requirement), we want as few slopes as necessary
Number of people: 4 (2 adults 40, 2 kids (4, 1) + 1 family member for the granny flat
Room requirement on ground/upper floor:
- originally 141m2 pure net requirement without circulation areas
Ground floor
- Open living/dining area with pantry
- Office (later possibly bedroom in old age)
- Shower bath
- Hallway
Upper floor
- 2 kids’ rooms from 13m2
- Bedroom as small as necessary + walk-in closet with standard wardrobes
- Bathroom with T-layout, shower, tub, toilet
- Second workplace
Office: Family use or home office?
- Home office x2 on 3 to 4 out of 5 days
Overnight guests per year: once per quarter
Open or closed architecture: open
Conservative or modern construction: "modern"
Open kitchen, kitchen island: Yes
Number of dining seats: 4-6 extendable to 10 (2m table extendable to 3m)
Fireplace: no
Music/speaker wall: no
Balcony, roof terrace: no
Garage, carport: prefabricated garage 3x7, possibly 3x9
Utility garden, greenhouse: yes (vegetables, fruit, cistern)
Further wishes/special features/daily routine, also reasons why this or that should or should not be

[*]we are Larch + Owl, so get up separately; with two kids (possibly someday 3), we consider the 2nd shower bath mandatory
[*]Open living/dining area as the heart: We cook a lot and gladly, social center in the house
[*]where possible standards (wardrobe widths, doors, windows, house shape etc.)
[*]if reasonable, then with basement
[*]Roofing from entrance to garage (currently still clarifying how we can/want to depict this, as this would most likely have to be >3m high with parapet and would probably require a building encumbrance on the boundary development
[*]Will very likely add "glass awning" on the terrace afterwards

- Our priority list

[*]Photovoltaic system
[*]Air-water heat pump
[*]Ventilation system
[*]Open living-dining area (L-shaped)
[*]Light-flooded rooms
[*]Maximum possible knee wall height
[*]Maximize clear room height ground/upper floor
[*]Living-dining area with floor-to-ceiling windows
[*]Daylight bathrooms
[*]Dining table 2m long (extendable to 3m)
[*]Modern look with individual accents
[*]Low roof pitch
[*]Interior doors at least 1m wide
[*]Shower bath downstairs
[*]Walk-in closet
[*]Pantry also as storage room
[*]Staircase not directly at entrance door (mud corridor)
[*]Office potentially usable as bedroom
[*]Kitchen island (min. 2m wide)
[*]Flat roof dormer and/or bay window
[*]Second workplace (bedroom, gallery, or similar)
[*]Bathroom T-layout
[*]Daylight in gallery
[*]Basement apartment
[*]Separate entrance to basement apartment
[*]Lift-slide element
[*]Maximize SW garden area
[*]Terrace partially roofed
[*]Sightline corridor-garden
[*]Daylight in walk-in closet
[*]Access to basement from outside
[*]Laundry chute
[*]Window seat
[*]SmartHome basics

House design
Who is the planner:

[*]Architect, service phases 1-3

What do you particularly like? Why?

[*]The ground floor in principle, many of our wishes reflected, a few highlights
[*]Bedroom + walk-in closet, probably an additional door will be added between
[*]Landing staircase, sightline, window in kitchen, hallway

What do you not like? Why?

[*]Ground floor: office oriented SW instead of east or southeast
[*]Ground floor living room: fixed glazing towards SW apparently still too small
[*]Ground floor living room: lift-slide element still too large, couch does not fit well
[*]Ground floor living room: consideration to have the entire wall glazed
[*]Ground floor: hallway quite long
[*]Upper floor is a function of the ground floor and therefore the rooms except bedroom + walk-in closet are relatively large
[*]Upper floor bedroom oriented SW instead of north
[*]Still considering making all upper floor windows floor-to-ceiling (except stairs, gallery); reason daylight + look
[*]Garage not directly attached to house due to passage to granny flat
[*]Granny flat quite elaborate
[*]At first we self-drew an L-shaped house similar to the post , but we could not manage the circulation areas and currently see them as a "necessary evil."

Price estimate according to architect/planner: 3,300 - 3,500 / m2, 700-800k + ancillary costs
Personal price limit for the house, including equipment: 750k + additional building costs
Preferred heating technology: sustainable + underfloor heating (comfort); geothermal would be conceivable, but not calculated with all the info we have researched so far

If you have to do without, which details/extensions
-can you not do without:

[*]Granny flat (for family + tax benefits)
[*]Office (need a fixed setup at least for one person, want to accommodate guests, also a retreat in the house)
[*]Two children’s rooms

-can you do without: probably everything else

Why did the design turn out the way it is now? e.g.
Standard design from planner? No; from architect
- We shared and discussed all our ideas and preferences with the architect beforehand
- This version is the second iteration; earlier there was an option with flat roof dormer with kids room towards SW, now discarded; as well as roof 25° (we will probably take)
Which wishes were implemented by the architect?

[*]a lot from above; but not everything possible

What makes it particularly good or bad in your eyes? We focus on the current pain points:

[*]Actually our space demand is lower, but we cannot depict this on the ground floor so that the upper floor fits (difference currently about 10-15 m2; kids rooms could all be smaller, circulation areas and gallery as well)
[*]Not yet optimal are the window areas in living/dining area, office and the relatively large living area upstairs; we are thinking of 1.10m fixed glazing and 2.50m lift-slide element
[*]House still relatively "buried"; idea: raise house overall or at least ground + upper floor by 40-80cm from ground
[*]The whole topic "catching house/garage," earthworks and plot modeling is very complex and elaborate
[*]No external blinds on gallery possible due to knee wall + roof
[*]Mud corridor + stairs separated; possibly a small disadvantage in old age, you will not be able to rent the upper floor separately in the future

Due to the maximum number of attachments, we cannot add an aerial photo of the tree stock. There are three large deciduous trees directly "under the nose" in the southeast and the southwest flank is provided with two chestnuts and about 15 pines from the 1950s. We are not worried about summer heat protection ;) - on the contrary: if we enlarge the house footprint, we would lose garden and especially light.

Feel free to contact us if you have any questions.
We look forward to your feedback and thank you in advance.

+ Basement apartment (for family and for tax reasons

At least honest in the statement that the reason is that it should be worthwhile for tax purposes. But still, the conversion etc. would have to be paid for. Isn't that a wrong or naive calculation? First of all, there have to be invoices in order to deduct them for tax purposes?! You don't get a basement apartment or a finished basement with the shafts for free! It is less suitable for rental, as it is very noticeable in the garden.

At least honest in the statement that the reason is that it should be tax advantageous. But still, the expansion etc. would have to be paid for. Isn’t that a wrong or naive calculation? First of all, invoices have to be available in order to deduct them for tax purposes?! You don’t get a granny flat or a finished basement with the shafts for free!

Hey ypg, thanks for the quick reply.

The train of thought is as follows: The granny flat is to be included so that the older generation first grows up with the kids and later is not left "alone." Currently, on one side, there is already only one person. Even if it cannot be planned very well, it is likely that on the other side something similar will happen with a time delay. It's all far off, but one of the reasons.

Sure: payment has to be made now. From what we can anticipate in terms of construction costs + incidental costs so far, it "pays off" for us in the long run and in the combination of family, kids, emotions + depreciation. That’s why the granny flat is not so easily dismissed by us. But we are open to all viewpoints and arguments. Our architect roughly indicated what efforts would be added there. We have compared our assumptions for the entire construction project.

It is less suitable for renting out since it is very prominent in the garden.

In the next 20 years, it will very likely only go to the family. How one separates off the garden for external renting afterwards has not yet been conclusively discussed. Ways will certainly be found. If necessary, "only" the flat would be rented out.

Just as an addendum, why we have chosen to proceed only up to work phase 3 so far and how long the "dough" has been resting.
As laypersons, we only became aware of the forum here relatively late. Until work phase 3, we felt well advised elsewhere. The dough has been resting for several weeks now. This was also the case from setting up the "wish concert" and reducing it, as well as between the first iterations of the drafts. Theoretically, we could still go through work phase 4 with the architect.

Perhaps a bit more context on the iterations of the drafts helps:

Draft 1 still had a door on the living room wall on the ground floor, so you could optionally enter either the living room or the kitchen. This would have almost completely eliminated the space available for furniture in the living room. We don't have a huge TV and only use it sporadically. But the doors right next to each other seemed rather pointless to us. The sightline from the living room towards the basement stairs was also only semi-good in our opinion. The compromise, therefore, is to go "through the kitchen." We would have preferred a clean sightline – of course. But then the kitchen would be too small.

There was also the idea to swap the living room and kitchen and to put the pantry on the back wall of the study. That did not convince us finally either.

On the upper floor, there was the idea of a dormer because of and in relation to the children's rooms. But that was at most inconsistent with the ground floor.

Good morning, I am asking about the window heights! They are important to me. We screwed them up and anyone still in the planning phase can prevent an overly large lintel from disproportionately disturbing the appearance. With what room height was it planned? Is it correct that the windows have a height of 2.08m!?

Number of people: 4 (2 adults 40, 2 kids (4, 1) + 1 family member for the granny flat

How old is the older person?