Hello everyone,
I seem to have stumbled on a problem and I have no idea how to fix it (if that is even possible).
I want to subdivide this model but when I do the windows all look weird.
Is there maybe a fix or something I can do ?
I am using edge split if that is of any help.
Thanks in advance 
Subdivision surface modifier + triangles on a non planar surface = poor result
You cannot just add a subsurf modifier to a mesh with just the aim to smooth it all out. You need a first have a good underlying mesh topology.
Ideally have even quad faces that flow along the shape of he surface
You can strengthen edges with additional edge loops or edge creasing https://www.blender.org/manual/modeling/modifiers/generate/subsurf.html
I know my topology is awful but is there really no way of at least improving it ?
Thanks
The windows and frames would also cause a high density difference so easier if you model those as separate geometry or separate objects.
Of course you can improve it. But if you intend to use sub-surf you’ll need to rework the topology to get rid of the triangles. Although in some rare circumstances you can use triangles and get away with it, I don’t think this is one of them. The topology is not awful. It’s just not suited to the modifier.
Have you tried mean crease around the windows??
