Planning a Single-Family House on a Slope - Optimally Utilizing the Plot

Hello dear forum,

we currently live in Vienna and have purchased a beautiful (and unfortunately very expensive) hillside plot west of Vienna. We already had an approved submission plan (!), which an architect made for us, but in February we pulled the emergency brake. Because through discussions with builders but also other trades (window manufacturers, installers, electricians) we found out that this plan would exceed our (initially agreed) budget by around 30-40% in execution – hence the emergency brake and restart: this time with an independent planner recommended to us by a builder who – in our opinion – is doing a good job and made the current plan together with us.
Before we continue (towards submission plan), we would like to have the plan “challenged” by you – as you can imagine, we have already invested a lot of time and even more nerves in this process with the architect, the new start and back and forth, and if possible want to start building still in 2019… because the future resident of one of the two children's rooms is already born and we want to move out of the small apartment as soon as possible.

Here is our questionnaire, which hopefully gives you a good overview of our project:

Development plan/restrictions
Plot size: 690 m² (19.5 m x 35.4 m)
Hillside: yes, approx. 5 m gradient over 35 m length
Floor area ratio: does not exist in Austria, 199 m² may be built on
Floor space index: does not exist in Austria
Building window, building line and boundary: front and side building setback each 3 m or half the eaves height of the facing house front, whichever is greater, rear building setback 3 m
Edge development: within the building setback up to max. 3 m height, allowance for elevation downhill following the terrain
Number of parking spaces: 1 unbounded parking space required
Number of floors: no restrictions according to the development plan, currently 2 floors planned
Roof type: flat roof
Style: Bauhaus
Orientation: south-east
Maximum heights/limits: 6.5 m on hillside / 8.5 m on valley side

additional requirements

Client requirements
Style, roof type, building type: Bauhaus, flat roof, single-family house
Basement, floors: 2 floors (for cost reasons), whereby the upper floor is at street level and the ground floor is partly built into the hillside
Number of persons, age: 4, 2 adults (mid/late 30s) and 2 small children, in the medium term it is expected that an older person will move in (grandmother)
Space requirements on ground floor and upper floor:
Ground floor (actually basement): large living area with living room, dining area and spacious kitchen, guest WC with hand basin, hobby room and storage rooms as well as the technical room

Upper floor (at street level): office/guest room, guest bathroom, wardrobe as well as large bathroom, walk-in closet (spatially separated from the master bedroom), utility room and 3 bedrooms (master bedroom, 2 children's rooms)

[B]Office: family use or home office? both
Guests per year: [/B]currently 6 times a year for a weekend, but potentially permanent use of the guest room
Open or closed architecture: open, but with focus on reducing noise transmission from the living area to the bedrooms
Conservative or modern construction: modern but timeless
Open kitchen, cooking island: open kitchen with large cooking island (peninsula) and direct visual contact to the dining table
Number of dining seats: yes, regularly 6 with possibility to extend to 10 on occasion
Fireplace: yes, in the ground-floor living area – should also be used as a room divider
Music/stereo wall: wall for large TV and floor-standing speakers
Balcony, roof terrace: no
Garage, carport: garage
Utility garden, greenhouse: raised beds for vegetables, preferably flat area for children's play area (sandbox, swing, …), shrubs such as elderberry bush and butterfly bush along the property boundary

It is planned to fill the original terrain by up to 1.5 m (flat area), which is why a retaining wall will be required in the lower garden area.

additional wishes/special features/daily routine, also reasons why this or that should not be:

Controlled residential ventilation, thermal building component activation for cooling, heating via geothermal energy (horizontal collector)

The walk-in closet should be spatially separate (at least by a door) from the master bedroom (because one of us always gets up earlier and the other should not be disturbed).

Orientation of the bedroom windows is directly into the garden and therefore not visible by neighbors.

Guest room/office and guest bathroom should be on one level so guests can find their way easily at night.

Large, more open space from living room, dining room and kitchen, whereby the area around couch & TV should be somewhat separated (niche).
[B]
[B]House design
Who planned it:
We originally planned with an architect and already had an approved submission plan. Unfortunately, it turned out from the offers of the builders that the architect’s estimate was significantly too low and the costs would have exceeded our budget considerably. Therefore, we have now created a new design together with a planner, which has also been roughly discussed once with a builder and should be within our budget.

[B]-Planner from a construction company: [/B]yes
[B]-Architect: [/B]no
[B]-Do-it-yourself: [/B]no
[B]
What do you like especially? Why? [/B]
The large open living area on the ground floor with direct access to the garden.

[B]What do you not like? Why? [/B]
Basically, we like the layout on the ground floor very much and it meets our needs, but the long staircase (17 steps) worries us – here we fear it could be too dark, at the same time we are also concerned whether noise will travel from the large living area to the bedrooms. Skylights would be possible, but we would like to avoid them so that the roof remains as simple as possible.
@Dark: The positioning and size of the windows is not final yet – we look forward to feedback here as well. As said, we worry that the hallway areas, but maybe also the large living area on the ground floor could be too dark. Please share your ideas.

Also, in front of the toilet on the ground floor (along the staircase) there is a lot of hallway space – maybe there is a better layout where less circulation space is needed?

Location and size of utility room on the upper floor – away from the bathroom and too small to place a drying rack.
[B]
Cost estimate according to architect/planner[/B]
Shell construction approx. 300,000,-
[B]Personal price limit for the house, incl. equipment:[/B]
600,000,-
Preferred heating technology: geothermal energy (horizontal collector)

If you have to give up, on which details/extras
-can you do without: garage (can be built later), garden fence, full completion of retaining wall, interior finishing of individual rooms (guest bathroom, 1 children's room, storage rooms), fireplace (can be expanded later),
-cannot do without: terrace roof, storage rooms and technical room

Why is the design as it is now?
For example, standard design from planner?
Which wishes were implemented by the architect?
A mix of many examples from various magazines...
What do you think makes it particularly good or bad?
The plot resulted from the division of a large meadow. The neighboring plots are currently still undeveloped (no buyers yet), the later development can only be guessed, which is why we orient the bedrooms toward the garden. The plot southwest next to ours is only 17 m wide, for example. It is therefore to be assumed that a future house here will be oriented longwise NE-SW (thus extending further downhill than ours) and will potentially use the 8.5 m max. building height.

Basically, the current plan is based on our experiences with the architect’s design and the learnings from the many discussions with the various trades to balance costs and our ideas.

[B]What is the most important/basic question about the floor plan summarized in 130 characters
[/B]
How do I optimally use the hillside location to implement the space concept and keep costs under control? What could be optimized?

Apparently, there are no load-bearing interior walls in this house. The 240 sqm does not show in the spatial effect of the house: in the garden level, the few rooms that no longer fit on the street level get lost; the street level itself, on the other hand, looks like a labyrinth crammed full of small chambers.

We already had an approved submission plan (!), which an architect made for us, but in February we pulled the emergency brake. Because through the discussions with builders but also other trades (window makers, plumbers, electricians) we realized that this plan would exceed our (initially agreed) budget by around 30-40% in execution

B. in terms of total size, I would also say regarding the present plan that it likewise exceeds the necessary space budget for the family by a similar margin (aside from the fact that grandma only has space in square meters, but not also a room);
A. then why don’t you show the canceled plan. If I understand correctly, that was also already for this plot; and maybe we’ll find a more successful reinterpretation.

P.S.: my failing memory thinks I should recommend you the following thread for reading:

I also think that the 10 cm walls urgently need to become load-bearing walls or partly rather 12 cm walls. But when you look at the "interlocked" upper floor, I find that the space is very well utilized. Although somewhat thicker walls (also between the children's room/parents' room) would still cost some space.

Unusual are the two height levels in the upper floor (probably because of the entrance level)... and yes, one might fear that noise from eating/cooking will be transmitted upwards. Now there is a half-height parapet planned on the upper floor... Possibly glass up to the ceiling there. But that will be expensive. Maybe one can try to have the staircase on the ground floor end with a spiral to the left on the plan and then place a full-height wall with a window opening toward the dining area.

In general, I would set the doors everywhere to at least 90 cm width in the shell construction (except toilets). The toilet doors should also be planned to open outwards, especially in the ground floor toilet, otherwise it will be too tight.

I would rethink and actually plan the kitchen and access to the storage once the attempt with the spiral is made. I would find a window in the right-hand wall on the plan desirable there.

Otherwise, all typical points of criticism such as
- laundry not where the laundry is generated
- wardrobe too small or only to be filled with 300 cm of cupboard
- cloakroom too small
- living room and sofa/TV position
are basically not present.

However, I would also be interested in the discarded too expensive plan, because this one is not without problems either.

We also have a lot of hallway space in front of the toilet on the ground floor (along the staircase) – maybe there is a better layout here that doesn't require so much traffic area?

If you place the wardrobe and utility room, the room unit in the middle, the bottom of the labyrinth, on the right side of the plan, everything should become somewhat less confusing and simpler.

In the medium term, grandma is supposed to move into the house. Which room has been assigned to her? And how is the barrier-free access arranged? ... medium term means soon, in a house construction possibly 5-10 years... has the fact been considered that grandma will then be older and possibly more frail?
Maybe the hobby room with the assigned WC should be planned a bit differently, because otherwise an elderly lady will be living upstairs in the office, excluded by the stairs.

Why don't they actually make the upper floor at ground level without having a few steps within this floor?