House Planning - Avoiding Mistakes in the Initial Phase

Hello everyone,

I/we will start building in about 3-4 years and I am already diligently researching. Better too early than too late. :)
I don’t know if there is already such a thread, but I haven’t found anything with my keywords in the search function. If there is, please forgive me. Here also the question of whether this topic even belongs in the right forum?

In our minds, the rough planning of our future dream house is already in place. The design and layout are inspired by the "Modo Home MH5". May I post a floor plan of this house here for a rough overview?

The suitable plot of land with approx. flat 4000sqm (no typo) is also already available --> the request for development connections is currently running.
Brief keywords:
- Bungalow with flat mono-pitched roof facing east --> Large window areas to the south/west
- Double garage
- Covered large terrace
- approx. 220sqm living space
- no basement
- large photovoltaic + battery (the next car will most likely be a BEV. Smart charging then with photovoltaic power)
- Controlled residential ventilation
- Possibly KNX control + alarm
- No dormer windows or roof structures (chimneys, satellite dish, etc.)
- Budget for the house approx. €400,000-500,000

Since we are still at the beginning of planning and I am also intensively dealing with materials (solid, timber frame construction, etc.), efficiency class, heating type (heat pump air/water or soil/water), I wanted to ask you what you would have done differently from the start in hindsight, or what one should pay attention to early on.

I would find fundamental things like "definitely do not build solid because..." helpful, as well as small things like "pay attention to a power outlet in area XY".
My plan is to build the house as "complete" as possible to later avoid things like high running costs, early remodeling measures, or also avoidable multiple sockets and cables, for example.

So far I have considered the following things:
- Completely single-story and barrier-free (also the showers, etc.)
- Wider doors (in case a wheelchair is ever needed)
- Wastewater heat recovery in the shower
- Centralized technology, e.g. ceiling speakers with central amplifier and things like an AV receiver and computer/server all go to the technology room.
- Many LAN/fiber optic connections in the rooms and in the ceiling (for access points).
- Many sockets with integrated USB-C ports.
- All cables that can become obsolete are installed in conduit pipes to make them easy to replace.

As you can see, this list is still very technology-heavy as we both work in IT. :)
I am currently reading up and informing myself in other areas.

This thread is also intended to point out things that other "home builders" might not have considered yet.
If you have any questions, feel free to ask them.

Regards

Always a bit difficult when there is no specific question.. What immediately strikes me: If it means what you get when you google MH5, you can quickly say goodbye to all the wishes of 400-500k. If more money is not possible, then get ready for a different house.

Forget the inspiration if you have a 344sqm top-class house as a template that does not quite meet your space requirements and may be 5-7 times more expensive. Even for your house with "only" 220sqm of living space (plus usable space, garages, terraces, etc.) and expensive equipment/design, you will experience a crash landing with your budget. Therefore, just one tip: reconsider your ideas, because they do not fit the budget.

Regarding the budget: That could also be adjusted slightly upward. Here I meant the house+garage itself. The plot is available, the development, outdoor facilities, etc. are calculated separately. Of course, there is no pool and not this super fancy equipment like the fire pit on the terrace or the wooden cladding etc. as with the show house included. This will be designed more simply. This house is more about the basic floor plan or the layout. Things like KNX and the like are only optional.

The suitable plot of land with approx. flat 4000 sqm (no typo) is already available

Hopefully you are aware of where the benchmark for cisterns on 4000 sqm plots lies in this forum *ROTFL*

The design and layout are inspired by the "Modo Home MH5". [...] - approx. 220 sqm living space [...] - budget for the house approx. €400,000-500,000

If you refrain from using the "rest" of the 4000 sqm entirely for park landscaping and driveway and instead sell it as building land, the budget should easily increase. Then you can also save yourself the considerable contortion of scaling down a 344 sqm millionaire’s mansion to a 220 sqm weekend house.

This thread should also be able to point out things not previously considered to other "home builders".

This forum already does that as a whole. Maybe you should try, instead of a search-function quickie, the classic approach of reading around here over several weeks.

Here I meant the house + garage itself.

The assessment did not go beyond that.
Just simply calculate with €2,500 per sqm of living space, which equals €550k. Add ancillary construction costs of €50k, a double garage for €30k, and some landscaping including the terrace for €50k.
Then you end up with a relaxed approx. €700k including the kitchen. This does not yet include the park’s layout, the photovoltaic system, or any major extras.