Opinions on our house concept

Hello everyone,
we will start building our house in the next 2-3 years.
It will be built 20 km west of Innsbruck in Tyrol. The plot is on a slight slope. Planned are 2 adults and 2 children.

I apologize in advance. This is the first step towards building the house. Of course, we have already inquired and have some ideas, but we are not experts. The considerations are still in the early stages and definitely have room for improvement, and that is exactly why I am here: I want to receive both positive and negative feedback as early as possible in order to build the most optimal house for us.

A brief explanation of the picture in the attachment. Based on the first information about the room layout and legal regulations, the draft inserted below is a first sketch of the initial ideas. Sketched with the limited means I have myself. The street side is north, and the garden is to the south. Due to the slope, we will drive the car into the garage in the basement, but at the same level as the street.

The building will mostly be made with steel prefabricated segments. The east, south, and west walls in the basement shall become retaining walls corresponding to the slope. On the north side, the steel frame should already be in place. The whole house should be well insulated, but we do not yet know exactly how and in which "class."
A decentralized ventilation system should be installed in the basement, in the living/dining area, in the toilet, in the bathrooms, and in the bedrooms. The reason for a decentralized ventilation system is the desire to control the temperature in individual rooms separately, also considering different daily routines, etc.
Heating in the bathrooms will be provided by electric underfloor heating directly beneath the tiles, so that the screed does not need to be heated directly. All other rooms will be heated with infrared heaters.
Regarding the flooring: all rooms will have "warm" coverings, such as parquet, linoleum, or cork. The bathrooms, of course, will be tiled, and that’s why there will be underfloor heating there.
shading for the living/dining area and bedrooms is also planned.
The entire building will be equipped with home automation (heating, shading, lighting, security system, etc.). Before anyone protests here: I am trying to do as much of this myself as possible. I gained experience with home automation during my training and am also a certified KNX installer. In the house, however, I want to rely on Z-Wave as the standard. The plan is to heat rooms where people spend very little time only minimally, for example the utility/hobby room. The bathroom only in the morning or evening. Only when someone is home etc. And thus save energy.
Since a high power consumption is expected with the planned electric car and the heating, a 15 kWp photovoltaic system is planned. The energy consumption will also benefit from a lighting concept with 100% LED. The current electricity price is about 14 cents/kWh, so probably on the cheaper side. With high energy demand, there are also alternative providers where, although the basic fee is higher, the price per kWh is lower. Here the provider can simply be switched if needed.

Please be merciful with me. I am not pulling these considerations out of thin air; I picked them up somewhere and they seemed logical and good to me. In our area, the described things are very unusual and there is little experience here. That is also the reason for joining the forum.

I hope you will help me develop our ideas.

You lose yourself in details like LED and smart home. Can you afford a house like the one sketched there on a hillside? It all looks very elaborate and large.

I am missing essential key data such as living area and budget for the house (excluding land).

Can you elaborate a bit on the infrared heating? How did it come about? Why don’t you want another system? Are there any experiences beyond "towel radiators"? Where/how are the panels installed? What kind of power is needed? How high is the efficiency? How "comfortable" is it? How high are the installation and purchase costs?

Regarding the floor plan: Is there (perhaps because of the heating) no utility room? Where is laundry done?

Hmm steel construction and z-Z-Wave I would think twice about it. Above a certain size of the house and the number of participants, reliability suffers enormously.

The whole house should be quite well insulated, though we don’t yet know exactly how and in which "class".

The reason for a decentralized ventilation system is the desire to control the temperature separately in the individual rooms.

Regarding the floor: All rooms have "warm" coverings. So parquet, linoleum, or cork. The bathrooms, of course, are tiled, which is why there is underfloor heating there.

The plan is to heat rooms that are only used occasionally only a little. For example, the utility/hobby room. The bathroom only in the mornings and evenings.

All of this doesn’t really fit together and partly contradicts itself.
- How are the rooms without tiles heated? Also underfloor heating?
- Controlling individual rooms is rather problematic in a new building by default. A decentralized ventilation system does not change that, as air is a poor heat carrier anyway. If you want to heat/cool spot-wise, I would rather rely on split/air conditioning units in the respective rooms (I have that at home myself). This works well despite a central controlled residential ventilation system.
- Since underfloor heating is quite sluggish and a clear permanent temperature separation within the envelope is difficult to achieve, I also consider it nonsense not to heat certain rooms at all, as they will be heated indirectly by the other rooms.

I find the house design pretty cool though. I’m just wondering what it will cost.
I’d roughly throw out 600k and up. Plus outdoor facilities + furnishings, etc.

I absolutely don’t understand why you leave out KNX as a KNX installer and prefer something else. Objectively, for a decent smart home there is only the price disadvantage with KNX. That disadvantage is irrelevant for you anyway if you can do it yourself.

Since a high electricity consumption is expected with a planned electric car and the heating, a 15kWp photovoltaic system is planned.

So you want to heat with a heat pump? Then forget quickly about the cooperation between a heat pump and a photovoltaic system. Because when the heat pump is running (winter), the photovoltaic system produces little; and conversely, photovoltaic produces in the summer when the heat pump is off. Photovoltaics with an air conditioning system or pool heating looks quite different.

I'll bring you together:

- How are the rooms heated without tiles? Also underfloor heating?

All other rooms with infrared heaters.