Aligning the house on the plot: North-South / East-West, what should be considered?

"in case maybe in 30 years..." Who knows if the children really want to stay in the area, if they even want to build, if one still lives there oneself,...

... or if anyone at all still lives there... currently everything is questionable. :eek:

Is that some kind of masochism?

The customer's will is his kingdom.

Perhaps one can also plan in such a way that later only one large extension for the grandchildren can be realized.

You can also plan it like this right away.

But please not in such a way that the garage is approached on an offset track (red dotted) – in my opinion, the partitioned plot would be better served with a hammerhead driveway (green boundary fence).
But this is just a critique of this specific proposal – I still lack the contextual assessment to evaluate the original question :-(

If it is really intended, then so be it. I would still take a close look at what compromises have to be made "in case maybe in 30 years..." Who knows if the children really want to stay in the area, if they even want to build at all, if one will still live there themselves,...

With that plot, I wouldn’t place the house in the middle anyway, in order to have a nice large garden. So why not consider how it works best?

On the contrary. There is no reason at all to plan for two houses. So why should one mess up their plot + house?

I am truly no friend of suppressing dreams that are 2 or more generations away. But you can plan for it, provided you do not have to submit to horrendous compromises. I'll put it in gambler's language that you apparently understand: you may give away 59, then you have still won. my suggestion: It must also be said: 30, 40 or 50 years later, one has a different claim on their house. This also applies to the evening terrace.

I’ll put it in gamer language, which you apparently understand:

I would understand having to sell part of the property in order to financially be able to handle the project at all. But compromises for a pipe dream that most likely will never happen? Nope.