Estimation of construction time for the new build of a semi-detached house

We had received a plan from the general contractor showing the start and end dates of all trades.

But apparently, they don’t keep it “updated” including the trades that come after the general contractor’s scope "on-site." But that’s exactly what this is about: the general contractor only does the partially finished weather-tight shell, then general contractor trades run in parallel with owner work, and afterward owner work and owner direct contracts get mixed up. Additional services from the general contractor may be available, but rather rarely.

Accordingly, it is supposed to be a "shell plus" house,

the general contractor only does

No, it reads classically as 'turnkey'. Fully habitable except for the wall and floor coverings that have been common for decades except in wet rooms. And here also the partition wall.

But they probably don’t do that "updated" including the trades that come "on site" after the general contractor’s scope of services. But that’s exactly what this is about: the general contractor only does the partially finished weatherproof shell, then GC trades come in parallel with own work, and afterwards own work and own individual contracts are mixed up. Adding that on from the GC may exist, but rather rarely.

Where do you read that? Own work here is supposed to be only walls and floors, that was the case for us too, as with most probably. And the trades that the GC does not do himself but commissions (sanitary, electrician, plaster, roof) were of course on the plan for us.

Yes, I also find it hard to understand the theater. Floors and painting are done when everything is finished. There is no need for anything to run parallel with the craftsmen.

Thank you very much for your responses.

We have actually planned nothing in parallel with the construction company. But we definitely need to coordinate everything with the painter and tiler.
I have already contacted a company for the paving work and they informed me that the first consultation appointment can only take place in 4 months!
I am worried that it might be similar with the painting and tiling work.
That is why I wanted to know if we can have an estimate of when it would be best to contact the painter.

The painter definitely wants to see what he is supposed to paint. Therefore, at least the walls should already be in place.