No, not for long - completely normal with a lot of EL. And anyway good for the construction...
long construction times only really make sense AFTER the screed. before that it's more or less just wasting time.
our experiences:
massive ready-made city villa from the construction company
kfw70, but with Kfw55 insulation (the eco-tier is missing)
construction time from June 15 to October 15
drying time mid August to end of September
ventilation behavior in summer after screed: all windows tilted open (of course only after laying the screed) and from time to time (5-6 times a week) quickly and intensively ventilated just for fun (the house simply wasn’t humid). no construction dryers, only the normal screed heating program of the gas boiler (also with windows tilted open). the meter ran quite a bit, but we didn’t care. we lived a bit further away, so daily multiple trips would have been more expensive.
the ventilation system runs constantly on 2 out of 3 in manual mode at our place. the room climate is always dry, we couldn't detect any humidity anywhere. all larger furniture stands away from the wall (sounds much less dramatic than it always does), the wardrobe has about 3-5 cm of air all around it (it is in a niche/of course it is free up to the ceiling at the top). we haven’t hung any pictures because our neighbor from the same company found mold behind their pictures. we have absolutely no condensation anywhere. in the bathroom we hang all our laundry, which the ventilation system easily handles. have to say though, we have double extraction in the upper floor bathroom because of a later sauna.
we had surprisingly few humidity problems during the whole construction phase. everything is still fine now.
we are very satisfied with the overall execution.
Our bathroom exhaust pipe goes through the unheated attic
no offense but how can a construction company execute something like that for you? did you sign off on this botched job (so you explicitly wanted it that way with all its risks)? that is explicitly not allowed and greatly promotes mold and co through condensation. even if not, water can collect somewhere and form nice germs.
as soon as the ventilation ducts are directly connected to the house and its heat, no condensation will form inside them and there is no reason ever to do anything. just always change the filters in the system and everything is fine.
ventilating through the ventilation system during the screed drying time is explicitly not allowed according to the operating instructions of any ventilation system. the warranty is now gone. there is simply way too much dirt present, which will definitely get into the duct network (no matter how). due to the enormous humidity, condensation can also form in the duct. I’d really think twice about it.