Retaining wall for the retaining wall!? Do you have any ideas?

A distance of 4 meters is not much, considering that an excavator has to position itself there and work.

In fact, the distance is less, since the new retaining wall is not placed directly under the existing one. Let's assume 1m, then the excavator would have 3m left. That's really little; it can no longer turn around.

I would try to find a solution without having to touch the retaining wall. If I remember our prices from 18 correctly, you’re looking at a small five-figure amount for the underpinning.

And here I see the problem that this can no longer be changed; as already mentioned, everything is already settled, both with the authorities and with the house builder’s plans... If we’re not supposed to touch the wall or the roots, then for entering the carport we only have the current 2m left. Even if it becomes 2.5m, driving in might still be possible, but I know that over time it’s only a matter of time before someone hits the house wall while backing out. Where am I supposed to get a structural engineer so quickly now, and honestly, five figures just won’t work anymore for all the love... I have to let this sink in and think further...

Where am I supposed to get a structural engineer so quickly now, and honestly, a five-figure amount just doesn’t work anymore for all the love in the world...

Finding a structural engineer shouldn’t be a problem. If you don’t know one in the immediate vicinity of your construction site, check the website of the engineering chamber of your federal state. There you will find member lists; under structural engineers, you can look for one near you. An appointment should be possible within 1-2 weeks, at least that was the case for us.
A structural engineer might have another idea and can perhaps already say something about the approximate costs.
For us, unfortunately, it was a mid-five-figure amount last year, but that all depends on the length and size.

Show us the plan finally. You just need to take a photo that has roughly parallel lines. Just leave out the [Planspiegel].

In my opinion, you should first ask the civil engineer for a supplementary offer for the support of the [SM]. He will know how that works and/or involve the structural engineer as well as the soil expert.

I would rather try not to touch the [SM]. I would initially consider the roots as a rather secondary problem.

Will this be a solid house? Concrete basement?

Last year, for us, it was unfortunately a mid five-figure amount, but of course, it all depends on the length and dimensions.

I would also assume that at first. If it turns out to be less, that's definitely good.

Without more information, I would say to plan parking spaces differently.

You can’t get away with just a pittance in this matter. Above all, it must be done right. Imagine L-bricks tipping/sinking.
It’s a bitter pill when something like that comes up at the start, but a slope is always a surprise.
Why are you deeper than planned?