Minimum room height in new construction

Hello experts,

I have found in the Thuringian Building Code §47 only a clear room height of 2.40m for living rooms. However, this does not apply to residential buildings of building classes 1 and 2.

The question now is whether we have to accept from our developer a room height in the living room bay (single-family house with 1.5 floors) of finished 2.44m, if no explicit room height is specified in the contract and the construction specification, but this is dimensioned as 2.508m in the contract and building application drawings.

We already perceive the 6cm under the usually standard 2.50m as oppressive and as a defect. But is it one? And what could we possibly do?

Thanks in advance for your professional assessment!

Can you upload the drawing from the plans and let me know if it is part of the contract?

Legally it fits - the question is, what exactly was agreed upon? 2.40m can still be found everywhere today, even in new buildings.

Enclosed is a detailed picture of the section.

We had previously always agreed verbally and then also in writing during the technical sampling that the bay window ceiling would be "flush" with the living room ceiling. That is why the separation was executed using a T-beam.

The entire ground floor features an open wooden beam ceiling, which in the bay window is filled between the beams with cellulose, beneath that a vapor barrier foil, then 3 cm of counter battens, and then a three-layer panel as the visible, glazed ceiling underside. The question, since it is now already built this way, would be: Can the counter battens be omitted here?

PS: The ceiling height in the entire ground floor is 2.50 up to the lower edge of the visible beam, then open spacing, only under the bay window were counter-battens + three-layer panel installed.

We had already come to terms with the insulation between the beams in the bay window because of the "balcony" above. (Although this probably could have been built somewhat higher?

Could be, but I cannot answer that reliably. If so, definitely at higher costs.

What bothers us, however, is the additional 6cm offset of the ceiling downwards in the interior with (discussed) & agreed "ceiling alignment"!

Therefore also the question: could the counter battens be omitted here from a construction-technical point of view? And can we demand that?

Demand .... how should we know that? No one was present at your discussions. Sometimes contractual components change subordinately as a result of necessary measures and simply have to be accepted as such.

Whether you can do that just like that ... You should ask the person who prepared your heat demand calculation; often an execution above the bay window (when there is no habitable space directly above) is decided in collaboration between the structural engineer and energy consultant.

Rhenish regards