Cost of ground slab for new construction in Hessen

Hello everyone,

we are currently in the planning phase of our new building in Hesse in the Rhine-Main area. The new construction of a [FH

in the second row on a plot of land we own is planned. At the moment, we only have 2 [FH] providers left in the running and both offers are, as so often, from the floor slab upwards. Therefore, we have also received an offer from a company for the construction of the floor slab, this company was recommended to us by an [FH] manufacturer.

Now I wanted to ask if someone can help me and tell me whether the offer on the one hand contains everything and on the other hand if the price is reasonable. It should also be mentioned that there is no soil survey yet (but will be commissioned soon) and therefore the costs for excavation are not yet fixed. Furthermore, we will hire a construction expert who will check the building specifications, the offer and the contract for work and additionally accompany and supervise the construction.

But here are the costs relating to my original question.

Steel floor slab 98.5 sqm floor area


[*]Structural calculation in verifiable form
[*]Site supervision
[*]Drainage

[LIST]
[*]Laying of sewer drainage pipes under the floor slab without backflow closure


[*]String line framework


[*]Creation for exact measurement of the building by the cadastral office or a survey engineer commissioned by the client


[*]PE foil


[*]Installation of a PE foil on the clean layer


[*]Reinforced concrete floor slab


[*]The floor slab is made according to the static calculation including the necessary reinforcement at a thickness of 25 cm, concrete C25/30


[*]Frost skirts


[*]Concrete C25/30, including excavation


[*]Foundation earth conductor
[*]5 m empty conduits for supply lines
[*]12,000.00 EUR

Clean layer

[*
Installation of a 15 cm thick capillary-breaking layer under the floor slab, grit size 11/22
[*]940.00 EUR


Rainwater drainage


[*]Laying of a rainwater drainage system with PVC pipes Dn 100, including necessary earthworks
[*]1,550.00 EUR


Sewer connection


[*]Creation of the sewer connection on the property including delivery and installation of a manhole consisting of:
[LIST]
[*]Concrete base
[*]Cleaning opening, open channel
[*]Concrete manhole rings, d = 100 cm, with ladder rungs
[*]Manhole cones 100 / 60 cm
[*]Cover 5 tons


[*]18 running meters trench excavation with backfilling, up to the street as a stepped trench, PVC pipe Dn 150, with the necessary fittings
[*]3,560.00 EUR

Rainwater cistern

[*]Usable volume 6,600 l
[*]Base and casing for infiltration with granulate 11/22, (soil must be suitable for infiltration), covering the granulate with filter fleece, vertical PVC pipe Dn 200 with closure cap for checking the infiltration function, including earthworks
[*]2,870.00 EUR

Tips and advice would be very helpful to us.

Thank you very much in advance!
Christian

To my understanding, a proper cleanliness layer is not a "15 cm capillary-breaking layer made of chippings". Because only on top of that (on the capillary-breaking layer) comes the cleanliness layer (e.g., 5cm C12/15). And on top of that then the foil.

Hello emer,

thank you for your reply. To make sure I understand correctly, from your point of view, for example, a 5cm thick layer of concrete should be placed on the [kapilarbrechende Schicht] and then the floor slab on top? Can you make a statement regarding the prices, whether they are within the expected range?

Whether the costs are reasonable, no one can tell you. In principle, you now need an offer from a second company. The problem is that it will be difficult to compare the offers. But I would definitely get a second or third offer. But be careful, it can happen that the one who wins is the one who leaves out the most from their offer and then makes additional claims.

And this raises the question of whether this offer includes everything

Hello emer,

thank you very much for your answer. To make sure I understand correctly, from your point of view, should, for example, a 5cm thick concrete layer be placed on the capillary-breaking layer and then the floor slab on top of that?
Can you make a statement about the prices, whether they are within the usual range?

In my opinion, the blinding layer was missing in your case. A foil or gravel is not a blinding layer.

Structure: gravel, concrete (as described above = blinding layer), foil, floor slab.

Your soil report will also contain a foundation recommendation.

Only then do offers make sense.