ᐅ Raise the roof structure

Here is the situation: I live with my partner in the top floor of my parents’ house (under the roof). These used to be our children’s rooms, but as a temporary solution, we converted them into an apartment. Originally, this was only meant as a stopgap due to limited space. However, since living spaces in our area are scarce and expensive, we are now considering staying there longer.

That said, we need more space. So, we have been thinking about raising the roof and redesigning the rooms. Additionally, we want to add a separate entrance and a balcony. Currently, the knee walls are only about 1 meter (3 feet) high, so they would definitely need to be raised significantly.

Do you think this is feasible, including moving interior walls? And what kind of costs should we expect? We plan to do much of the interior work ourselves, like laying the flooring, etc. Do you think a budget of around $200,000 would be sufficient?

Since I really have no experience with this, I’m hoping for your advice.

Yes, the first question is whether it is eligible for approval. You can find that out at the building authority (building permit / planning permission office).
The second question is whether it is structurally feasible; you can find that out from the structural engineer.

I’m just speaking generally here. I understand that building permits / planning permissions are required 🙂

But that is the most fundamental point: if the authority says that two full stories are not allowed there, then you don’t need to consider anything else.