Planned floor slab too deep?

Hello everyone,

I had a plan/approval plan made by an architect for an extension to an existing residential building. He determined the basics and measured everything. The building permit was granted. Now, at the start of construction, I noticed that (according to the plan) the top edge of the floor slab is 20 cm below the level of the channel inlet / drain pipe. This means that the house would fill with water when it rains. The water cannot drain to the sides because the property is built up. Is this a planning error, or is the architect not obliged to provide a drainage plan?

Hello TD-210p

What kind of assignment does the architect have? An extension at the same height as the existing residential building? Then he planned correctly. He should have already pointed out to you the discrepancy between the height of the extension and the height of the sewer. As it is now, you have to raise the water. A sump pump or lifting unit is necessary. How is the problem solved in the residential building? There, the sewer must necessarily be higher than the floor slab.

Steven

That means that the house would fill with water when it rains.

The rainwater will behave the same way as with the residential house, since the level will be the same due to the screed and floor covering.