Re-roofing yes or no

It is about the renovation of a semi-detached house built in 1980.

It will be gutted except for the exterior walls. Currently, I am thinking about the roof. A roof expert said the roof is still okay.

I am considering a bit, now that I have the big mess anyway, it could be done.

The main reason for my consideration is the insulation issue. The roof currently has no proper underlay. And I keep reading that it is hardly possible to create good insulation only from the inside. What do the professionals think?

The roof has a total area of around 120 sqm. Are there any basic rules about what costs I can expect?

Since it is a semi-detached house, could we use different tiles than the neighbor? How is the transition handled?

Re-roofing costs quite a bit. It’s not cheap. I would get a quote for just installing insulation and then one for the complete job. If a professional installs the insulation from the inside, it should work well. Before tackling the issue, I would first talk to your neighbor to see what he thinks about re-roofing. Maybe he’ll join in if you really want to do it.

Best to collect offers from two to three companies, with coverage and only one insulation. As Koempy already wrote, such a roof costs quite a bit of money....