Building merge parts

How to find and merge diffrent parts of the building, if there is no building relation tag. For example this one: 120 Wall Street

Can you please give us a to that building?

Yes, here you are

Don’t merge the lines of this building! They represent the outline in different heights for a 3D model of this building, you can see here .

A lot of buildings there in New York are entered to be shown with this 3D renderer.

Yes, but I need to merge them, because I try to compose 3d model of that building

Vladimir, I recommend to proceed in the special 3D subforum here: