Removing Load-Bearing Wall in Timber-Framed House

Question

I live in a house that was built in 1976 using timber frame construction (prefabricated house / Fertighaus). In the ground floor, we want to remove a load-bearing wall. This was the initial state:

We have removed the 2 doors and the paneling (chipboard and plasterboard / Spanplatte und Rigips). Underneath, there are wooden beams with a thickness of 8 cm. Currently, it looks like this:

Now we want to remove some of the beams and only install 1 new beam. Above, we want to place a support beam to ensure structural stability. We plan to use glulam beams (Leimbinder) for both. This is the plan (the 2 dashed beams are the new that we are planning to construct):

The upper beam would be approximately 315 cm long and 20 cm high. The lower beam would span the entire height and be 8 cm wide. Both beams would have a thickness of 8 cm.

This is a section of the floor plan. The green area is the wall that we want to remove:

Is our plan feasible from a structural perspective?

The house has 2 floors (+ attic) and no basement.

Answer 1

What you're proposing and/or actively doing is a major structural change to the building. As such, you need to be sure that it's both safe and building code compliant. There is no way any random internet folks can answer this question since there are many details that go into determining the proper design of a building support structure.

You need to enlist the services of a qualified structural engineer or architect who can properly analyze and design the needed elements to support the structure. In the USA you want a P.E. (Professional Engineer) who will have a state-issued license and who is qualified in this area of practice. In some case a licensed architect can also perform these services but you need to check to be sure.

In most cases you will need a building permit to perform such modifications and in order to get a permit, you will certainly need plans signed by an engineer or architect.