ᐅ Opinions on Our Home Design

Hello everyone,
we plan to start building our house within the next 2-3 years.
The location is about 20km (12 miles) west of Innsbruck in Tyrol. The plot is on a gentle slope. The house is planned for 2 adults and 2 children.

I apologize in advance. This is the very first step towards building our house. Of course, we have already researched and have some ideas, but we are not professionals. Our thoughts are still in the early stages and certainly have room for improvement, which is exactly why I’m here: I want to receive both positive and negative feedback as early as possible to design the best possible home for us.

A brief explanation of the attached image: Based on the initial information about the room layout and legal requirements, the sketch below is a first draft of the initial ideas. It was drawn with the limited tools I have available. The street side is north and the garden faces south. Due to the slope, the garage is accessed by car through the basement level, which is at the same height as the street.

The house will mainly be constructed using prefabricated steel segments. The east, south, and west walls of the basement will serve as retaining walls appropriate for the slope. The steel frame should already be in place on the north side. The entire house should be well insulated, although we are still unsure about the exact level or “class” of insulation.
A decentralized ventilation system should be installed in the basement, living/dining area, restroom, bathrooms, and bedrooms. The reason for a decentralized system is the desire to control the temperature in each room individually, as well as to accommodate different daily routines, etc.
The bathrooms will be heated with electric underfloor heating directly beneath the tiles, so the screed does not need to be heated. All other rooms will be heated with infrared heaters.
Regarding flooring: All rooms will have “warm” floor coverings, such as hardwood floors, linoleum, or cork. Naturally, the bathrooms will be tiled, which is why underfloor heating will be installed there.
Shading is planned for the living/dining area and bedrooms.
The entire building will have home automation (heating, shading, lighting, security system, etc.). Before anyone objects: I will try to do as much of this myself as possible. I have experience from my training with home automation and am a certified KNX installer. However, I plan to use Z-Wave as the standard in the house. The idea is to only heat rooms that are in occasional use minimally, for example, the multi-purpose/hobby room. Bathrooms will only be heated in the morning or evening, and only when someone is at home, etc., thereby saving energy.
Because a planned electric car and the heating system will result in significant electricity consumption, a 15kWp photovoltaic system is planned. The energy consumption will also benefit from a lighting concept using 100% LEDs. The current electricity price is about 14 cents/kWh, which is relatively low. For higher energy demands, there are alternative providers offering a higher fixed fee but a lower price per kWh. The plan is to switch providers if needed.

Please be patient with me. I’m not inventing these ideas myself; I have picked them up somewhere and they seemed logical and useful to me. In our region, these topics are quite unusual, so there is little local experience. That’s why I’m turning to the forum.

I hope you will help me develop our ideas.

You are getting caught up in details like LED and smart home systems. Can you afford a house like the one outlined there on a hillside? It all looks very elaborate and large.

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

Could you elaborate a bit on the infrared heating system? How did you decide on it? Why don’t you want to use another system? Are there any experiences beyond just “towel radiators”? Where and how are the panels installed? What output capacity do you need? How efficient is it? How “comfortable” is the system? What are the installation and purchase costs?

Regarding the floor plan: Is there no utility room (maybe because of the heating system)? Where will the laundry be done?

Hmm, steel construction and z-Z-Wave, I would reconsider that. Beyond a certain house size and number of participants, the reliability decreases significantly.

MuHaha202 schrieb:
The entire house should be well insulated, although we don't yet know exactly to what standard or "class."

MuHaha202 schrieb:
The reason for a decentralized ventilation system is the desire to control the temperature separately in each room.

MuHaha202 schrieb:
Regarding the flooring: all rooms will have "warm" surfaces, such as parquet, linoleum, or cork. The bathrooms will, of course, be tiled, which is why there will be underfloor heating there.

MuHaha202 schrieb:
The plan is to heat rooms that are rarely used only minimally, such as the utility/hobby room. The bathroom will be heated only in the mornings and evenings.

This doesn’t really add up and contradicts itself in places.
- How will the rooms without tiles be heated? Also with underfloor heating?
- Independent temperature control of individual rooms in a new build is generally quite challenging. A decentralized ventilation system won’t change this, since air is a poor heat conductor anyway. If you want to heat or cool specific rooms individually, I would recommend split or ductless air conditioning units in those rooms (I have experience with this myself). This works well even with a centralized mechanical ventilation system with heat recovery.
- Underfloor heating is quite slow to react, and it is difficult to maintain clear and permanent temperature zoning within the building envelope. So I find the idea of not heating certain rooms at all a bit impractical, since those rooms will then be passively heated through adjacent rooms.

I actually think the house design looks pretty cool. I’m just wondering what the cost might be.
I would roughly estimate at least 600,000 (plus landscaping, furnishings, etc.).

I don’t understand why you would skip KNX as a KNX installer and choose something else instead. For a proper smart home, the only real drawback of KNX is the cost. But in your case, since you can do the installation yourself, that disadvantage doesn’t apply.

MuHaha202 schrieb:
Since a high electricity demand is expected due to an electric car and heating, a 15kWp (kilowatt peak) photovoltaic system is planned.

So do you plan to heat with a heat pump? Then you should forget about the synergy between a heat pump and a photovoltaic system. When the heat pump operates (in winter), the photovoltaic system produces very little energy. Conversely, in summer when the heat pump is not running, the photovoltaic system produces a lot.
Photovoltaics work differently in combination with air conditioning or pool heating.

I'll sum it up for you:

matte1987 schrieb:
- How are the rooms heated without tiles? Also underfloor heating?

MuHaha202 schrieb:
All other rooms with infrared heaters.