Large detached single-family house with full basement - install basement drainage by own work

Hello everyone,

we are building a solid single-family house with a full basement and are installing drainage ourselves. This is not necessary, but we want to be on the safe side.

We will probably lay "Fränkische" DN100 slotted pipe around the house, as well as a control shaft at every corner and a pump with connection to the infiltration system in one of them. I have made the following considerations regarding the setup:

We lay a layer of gravel, then the pipe, then backfill with gravel (how high should this be? Is about 30 cm above the pipe sufficient?) with a fleece fabric on top. A fleece is also applied to the basement wall (insulation), as suggested by Fränkische. Then backfill with topsoil up to the upper edge.

My questions are:

Which gravel should be used? An acquaintance (landscape gardener) suggested 8/32 or 16/32. Fränkische recommends 8/16.
Are there other (better) fleece fabrics or should a dimpled membrane be installed on the basement wall so that the water drains better there?
Should fleece also be laid around the pipes?
At what height should the DN100 pipe be installed? Should it perhaps be laid below the level of the slab?

Do you have any other tips?

Thanks in advance

The DIN 4095 specifies the following:

The thickness of the gravel packing (filter layer) surrounding the drain pipes depends on the grain size distribution of the filter layer or filter soil.
For a grain size distribution of 0/8 mm, 0/32 mm (mixed filter according to DIN 4095 2.11) or 4/16 mm (filter layer), a minimum thickness of 15 cm must be maintained.
For a grain size distribution of 0/4 mm or 4/16 mm (both filter layers), 10 cm are sufficient according to Table 6 of DIN 4095.

Whether a geotextile fleece must additionally be installed around the gravel packing of the drain pipes depends on the in-situ soil, the backfill material of the excavation, and which grain size distribution was used to surround the drainage pipe.
Encasing the drain pipes with at least 20 cm of gravel sand with a grain size distribution of (0/32 mm / 0/8 mm = mixed filter) can make encasing the filter layer dispensable if, in addition, the excavation above the drain is backfilled with the same filter material.

Here is a small sketch from DIN 4095:


The pipe must lie with its invert at least 20 cm below the top edge of the floor slab at the highest point of the installation. From there, the drainage pipe is laid with a slope of 0.5%.