Adding floors - Structural stability questionable

Hello,

The living space amounts to 140 sqm and the house is partly basemented. So the additional floor should actually not exceed 105 sqm, although to my knowledge the sqm with sloping roofs are not fully counted, right?

Yes, the 2.00 m line is the magic word. Everything below that is only partially or not at all counted towards the living space; however, this calculation does not change the fact that the floor area remains the same. It can also be well used as storage space with clever planning, for example.

The building plan with static calculation is still available. My father doubts that an additional floor is possible without extra reinforcement.

Are your parents aware that they cannot stay in the house during the renovation measures, regardless of whether stabilizing measures have to be implemented or not?

The next steps would now be, if I understood correctly, to coordinate financing with parents and bank and then go to the static engineer or architect with a concrete amount (pay attention to how the consultation is compensated).

Yes, or go to a contractor with the existing documents who is experienced in renovating existing buildings. In my opinion, it is also not wrong that—if it comes to expansion—an external expert accompanies the construction project. In the first step, I would always try to obtain as reliable information as possible about the expected construction costs. Everything is still theoretical; the preliminary expenditure until planning certainty should remain manageable.

And don’t forget to go to a tax advisor/notary and clarify your respective shares in financing/ownership. Everything is fine as long as a couple understands each other; even better if binding regulations are created in good times for less good times.

Rhenish greetings

I think that a solution satisfactory to all parties can be found regarding the financing. Also, after now 10 years of "common-law marriage," a wedding is coming up in the foreseeable future, as the family planning is slowly starting (here, multi-generational living is also a plus). Fortunately, an acquaintance rents out a house about 100 m away for a limited time, where my parents could move in and out on short notice. We could practically carry furniture etc. from one front door to the other.

It mainly depends on how costly any structural renovation measures might be.

My "parents-in-law" noted today that there might also be funding if we combine everything with measures to improve energy efficiency (e.g., a new roof). No idea what is possible there. But that would then also have to be known by the architect or the structural engineer.

It would be interesting to find out whether and how these [Bauträume] could be realized.