Terrace: Three different realization ideas from three landscapers

Hello everyone,

we recently built and are currently planning our garden with a terrace. The terrace should face south and be 40m2. For the slabs, we have planned 80x80x2 porcelain stoneware. The terrace should be accessible from the living room via a minimal step of 1 cm. We have obtained offers from three landscapers. Each of them has a different implementation idea:

[*]Mineral concrete + grit + slabs with a channel in front of the door + curbstones
[*]Mineral concrete + 5 cm drainage concrete slab + slabs + without channel + without curbstones
[*]Gravel + fleece + grit + slabs + without channel + curbstones

What do you think of the implementation ideas?

Thanks in advance

For 2cm slabs, I would use drainage concrete. Also curbstones, because without them, overgrowing grass & co. always looks untidy. A channel is actually mandatory; with a terrace roof, I would waive it.

For 2cm slabs, I would use drain concrete. Also curbstones, because without them it always looks untidy with invasive grass & co. A channel is actually mandatory, but I would do without it if there is a terrace roof.

Thank you for the answer. Why drain concrete? Is drain concrete gravel mixed with cement?

Why drainage concrete? Is drainage concrete gravel mixed with cement?

This is a single-grade concrete, which is permeable as a result. Not simply gravel with cement. I prefer to say, why not gravel. Because with extremely high probability the slabs will start to wobble at some point (sooner rather than later).