ᐅ Increase the finished floor level of the living area

Created on: 14 May 2021 18:43
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Fritsch
Hello everyone,

Our basement has a reinforced concrete ceiling, above which are the upper floor and the terrace. Since the terrace needs to be insulated, there is a height difference of about 25cm (10 inches) between the terrace and the adjacent living area (kitchen, dining room) on the ground floor. Steps at the doors leading to the terrace don’t look very good, so our builder is currently planning to fill this height difference with several layers of screed. Is this the most cost-effective option? For 225m² (2,423 sq ft) of surface area, the screed is currently estimated at 18,000 € (net); 115m² (1,238 sq ft) of that will have multiple layers. Do you maybe have cheaper alternatives? The house will be heated with underfloor heating. Thanks in advance.
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Fritsch
14 May 2021 20:38
What does klauen mean?
I’ve attached a cross-section. Because of the insulation of the basement ceiling under the terrace, it is higher than the living area on the ground floor. This height difference is supposed to be evened out with screed...

Schnitt durch Gebäude: Terrasse, Küche, Büro, Flur UG; Stahlbetondecke, Fundament; Mensch im Flur.
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kbt09
14 May 2021 20:49
What will be the remaining clear ceiling height on the ground floor after this floor level increase?
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user-d29
14 May 2021 20:50
Who plans something like this without considering the heights? All of this could have been planned differently and correctly. Or is it no longer possible now?

Solution: Reduce insulation by using different materials and a combination of internal and external insulation.
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hanse987
14 May 2021 21:17
Reminds me a bit of the "robber construction." You didn’t notice it on the plans, but only once the shell structure was completed.
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Fritsch
14 May 2021 21:23
Thank you first of all for the numerous replies.
kbt09 schrieb:

What will be left of the clear ceiling height on the ground floor after raising the floor level?

The height is planned to be 2.6m (8 ft 6 in) in the ground floor.
nordanney schrieb:

Who plans such a mess without considering the heights? This could all have been planned differently and properly. Or is that no longer possible?

Solution: Reduce insulation thickness by using different materials and a combination of interior and exterior insulation.


The building permit / planning permission is approved. Unfortunately, the architect did not inform us about the height difference; our general contractor only mentioned now that the screed will be more expensive because of it.
The energy consultant (KfW55 standard) planned 20cm (8 inches) polystyrene (PS), tapered insulation, and a ventilated air layer of 2cm (0.8 inches) for the insulation under the terrace. Which insulation would be equally effective but thinner? What do you mean by a combination of interior and exterior insulation?
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user-d29
14 May 2021 22:14
Fritsch schrieb:

Energy consultant (KfW55) recommends 20 cm (8 inches) polystyrene (PS), tapered insulation

PUR insulation with a thermal conductivity of 0.022 W/(m·K) or similar is better.
Fritsch schrieb:

What do you mean by a combination of internal and external insulation?

Insulation on the terrace and internal insulation below the ceiling (e.g., PUR or resin foam with aluminum foil facing).

I insulate my 1960s building, for example, only with 12 cm (5 inches) resin foam on the outside, easily meeting KfW 55 requirements.