ᐅ Basement construction with waterproof concrete tank and insulation

Hello everyone,
in the construction specifications from the developer, the following is planned for the basement:

"Reinforced concrete slab, according to foundation requirements, on gravel fill if necessary. Exterior walls made of reinforced concrete with applied exterior perimeter insulation up to a height of 1 m (3.3 ft) below the basement ceiling.
EXTERIOR THICK COATING ON THE BASEMENT OUTSIDE WALLS. THE LOWER LEVEL IS EXECUTED AS A WATERPROOF STRUCTURE (‘white tank’) UP TO THE HEIGHT BELOW THE BASEMENT WINDOWS. INTERIOR WALLS ARE CONCRETE OR MASONRY. CEILING ABOVE THE LOWER LEVEL IS A CONCRETE SLAB. The subordinate technical rooms or basement rooms in the lower level do not meet the requirements for lighting, heating, and ventilation for what is called ‘demanding use.’ It is a pure waterproof concrete structure (‘white tank’), therefore the exterior walls are not insulated down to the slab, and the basement floor remains uninsulated in these rooms. Storage of moisture-sensitive materials such as paper, sugar, etc. is not recommended."

Is this sufficient for a semi-detached house where the basement is intended solely as a standard storage or utility space, and not for living purposes? Does this type of construction comply with current standards?

Good evening Harry Potter’s friend Dobby,

this is actually a matter for reviewing and assessing the construction documents.

Dobbylein schrieb:

"Ground slab in reinforced concrete, based on founding requirements, on gravel fill if necessary. Exterior walls in reinforced concrete with applied external perimeter insulation up to 1 meter (3.3 feet) below the basement ceiling height."

What happens if no gravel is needed? How will the foundation be made then?

Dobbylein schrieb:

"EXTERNAL THICK COATING ON THE BASEMENT EXTERIOR WALLS. THE LOWER LEVEL IS EXECUTED AS A ‘WHITE TANK’ UP TO THE HEIGHT BELOW THE BASEMENT WINDOW."

Why? Does the basement end below the light well, or is only the rest below surrounded by soil? And why is it referred to as both basement and lower level?

Dobbylein schrieb:

Does this construction method meet the requirements for a semi-detached house where the basement is intended solely as a regular basement space and not for living purposes or similar?

As long as the heating unit is not to be installed in the basement: in my opinion, yes. Otherwise, the room intended for that must be insulated and heated.

Dobbylein schrieb:

Does this type of execution comply with the state of the art?

No one can answer that without the geotechnical report and the rest of the construction documents. For example, from your description, it is not clear which waterproofing according to DIN xyz is planned for the ‘white tank’.

Best regards, Bauexperte

Thank you for the reply.
This is a basement level, also referred to as a lower ground floor. The basement has 3 rooms, one of which contains a pellet heating system. The other two rooms are purely utility spaces.

I am not very familiar with this subject, but I found it odd that the basement's exterior walls are not insulated down to the floor slab. I cannot determine whether this is standard construction practice...

Hello,

Dobbylein schrieb:
..... The basement has 3 rooms, one of which contains a pellet heating system. The other two rooms are purely utility spaces...... I can’t understand whether this is standard construction practice...

First, you should check the Energy Saving Ordinance / KfW certification. Based on this description, the basement as a whole, including the heating system, is outside the thermal envelope.
Therefore, the basement rooms must not be used as living spaces and should not be heated accordingly.
According to this setup, the basement ceiling appears to comply with DIN 4108 Supplement 2, which is fundamentally correct!

Best regards