How steep is the access to the carport?

Does the development plan allow this? Usually, at least 5 m distance to the street is common.

Yes, our development plan allows almost everything... except specifications on the number of floors and basically nothing is stated except the plot ratio and floor area ratio.

Development plans are not everything. In your community, there is surely also a parking space ordinance. These usually require 2 spaces for a single-family house. And if the 2nd is in front of the garage / carport, then usually 5m have to be estimated for it.

But your planner should know that.

A development plan is not everything. In your municipality, there is certainly also a parking space regulation. These usually require 2 spaces for a single-family house. And if the 2nd one is in front of the garage / carport, then usually 5 meters have to be allocated for it.

But your planner should know

It would not matter anyway, since we want to place 2 parking spaces under the carport and possibly one more parking space somehow next to it... but 2 are planned anyway.

However, our architect urgently advised us not to exceed 12%, as 15% can already be very tight for some cars.

It is not the incline itself, but the transition from the road to the incline that is the problem. A sharp "break" from 0% to 15% incline or several rows of cobblestones that gradually become steeper step by step? There is a lot of potential here to make the embankment easily drivable despite the steep incline.

Not the slope itself, but the transition from road to slope is the problem. A sharp "kink" from 0% to 15% slope or several rows of cobblestones that gradually – gently – become steeper? There is great potential here to make the embankment drivable despite the steep slope.

That is of course true. However, with only 3m length, there is hardly any room to decide when to "properly start" the slope... you also have to gradually flatten it out again.
Well, we have now decided that the carport will be set lower than the house and the adjacent room and will either make a "step" next to the room using L-shaped blocks or create a small embankment with the carport below.

Well, we have now decided that the carport will be set lower than the house and the adjoining room, and we will either make a "step" next to the room with L-bricks or a small embankment with the carport below.

We did it something like that as well. The garage is located quite a bit lower. Our L-bricks behind the garage are 1.30 meters high. Then you can go from the garage to the house either via the stairs or the slope without steps. In between, we also have an embankment.

Many greetings

Axel