Assessment of land - hillside location

Your calculation may work out, but it doesn't have to. This is how you can calculate if you haven't made a "tight" budget. Depending on the soil class, house provider, and demands on the initial terrain modulation or garden design, quite a bit can still be added.
Thoughts on this:

[*]Park the cars in the basement, so they don't take up space on your not-so-generous plot.
[*]Build only the square meters you really need and want to maintain. Since it's unclear for how many people you are building, the 150 sqm cannot be assessed.
[*]If you have some skill and time, you can take on the garden design yourself. If you also have some ideas and imagination and don't like the run-of-the-mill paved terrace, awning, hedges, and rolled lawn, you will gradually build a very nice garden with little money. Terrain design with "flow" is cheaper and often more attractive than the "brutal terracing" method with concrete. If you have it done, your budget is too tight. Have courage for your own idea!
[*]In the end, what counts for your quality of life is not what "people do," "the neighbors think," what "a horde of forum members says," or how much a sqm of house cost. What counts is how well house and land make your life (even) more beautiful.
[*]Slopes often have surprises - set aside a risk amount and ring the neighbors to find out what surprises they experienced during construction.

Additional construction costs would have fit with us now. We have around 60k despite massive earthworks (excavating 1200m3 (including topsoil) and transporting away 880 m3, the rest was used on the site), but that largely depends on how much the landfill costs you. We were able to partially transport excavation material to another property and for the rest we paid 14.5 EUR per m3 including transport and disposal. I have also heard completely different prices.

And I still believe that 15k for the garden is never enough. Even if you slope everything, don't build walls, pave yourself, build stairs yourself (which are probably unavoidable on a slope). With the tightly budgeted calculation, I would recommend a 50k buffer for you. I would bet that you will need most of it for the outdoor facilities and the rest will be used as a general buffer inside the house.

UG is cheaper here. Especially since you then have direct access to the south garden.

You could roughly make it work with the budget if there are no surprises and you don't build larger than you need. Just tips from Hampshire. I just wouldn’t put the garage under the house. That gets the best spot on the property.

We also have a proper hillside location and then built with a basement with an interior double garage. The driveway is level with the street and the ground floor at the back is level with the garden. I think that's a good solution. But for excavation and disposal and later backfilling, a few euros naturally add up. 20,000 could be tight. But of course, it depends on the soil class and whether the excavated soil can be used for backfilling. Unfortunately, we had to take 1300 tons to the disposal site.

I would just not put the garage under the house. It gets the best spot on the property.

I take that back, since otherwise you would have to drive through the garden. I had briefly confused the location.

You build stairs yourself (are probably unavoidable on a slope

Firstly, stairs are certainly not necessary on this slope and secondly, something like that is very easy and inexpensive to realize in the garden – for example in the style of Tuscan hiking trails through vineyards. That costs almost nothing. Or you place a few larger rough stone blocks as steps with an excavator – the construction workers do that on the side for a tip if you have them delivered. In the garden, it shows that with imagination you can get along very well with less money.

Hello everyone,

first of all, thanks for the many constructive feedbacks

Here again the budget, a bit more detailed:

Plot: 55-70 TEUR incl. additional costs
(standard land value is 65 EUR/sqm -> that would be 50 TEUR)

Additional construction costs: 70.6 TEUR
Building application: 1 TEUR
Building permit: 0.6 TEUR
Soil survey: 1 TEUR
Surveying costs: 2.6 TEUR
Earthworks: 30 TEUR
Foundation slab: 15 TEUR
Construction water/electricity: 0.5 TEUR
House connections (gas, electricity, water, telephone, possibly cable): 13 TEUR
(the plot is developed)
Tree removals: 1.5 TEUR

Review of construction contract: 0.5 TEUR
Land charge registration: 1.5 TEUR
Construction expert (BHB): 1.9 TEUR
Construction insurances: 1.5 TEUR

House (turnkey, incl. floors and painting works): Max. 320 TEUR
No garage planned, but possibly a cheaper wooden carport, roughly what costs would come on top?

Outdoor facilities: 30 TEUR
What would be possible with this budget?
Urgently necessary: driveway, terrace, splash protection for the house

Miscellaneous: 20 TEUR
Kitchen: 10 TEUR
Furniture, lamps, small items: 10 TEUR

Total budget: 510 TEUR

Is something still missing in this list?
Where might there still be potential or risk for cost changes?

This is already the absolute upper limit of what we wanted/could spend.
We aimed rather for 450-490 TEUR. It really shouldn’t be a fancy house, a normal standard house without bay windows etc. is sufficient for us.

We calculated roughly 150 sqm in terms of area. If all goes well, there will soon be three of us and a second child is planned for later. So the house unfortunately cannot be much smaller :-/

On a flat plot, I think one could manage well with a budget of 450 TEUR for our requirements. This will probably not be feasible with the plot offered to us, right?
But the plot is probably the last free plot in the town where we would like to move for family reasons.