You’re going to have to break it up into pieces, you can only use one lightmap per object so as a single mesh it won’t get enough lightmap coverage
As far as how you can do it better, there’s some places where you can remove polygons but it’s not that big of a difference. The stuff that’s going to become difficult is when you will have to add details to the rooms. Besides all the props and stuff like that you’ll be needing to add doors/windows/molding and stuff like that which will be very tedious for a building of that size.
The way I would do it is to break the walls into modular parts. Usually in buildings you have standard lengths of walls which lends itself perfectly for modularisation of the layout. I can already see there are set lengths that are repeated over and over within the layout.
yea so why should i bother making new walls when i can use the ones in the editor itself? (apart from that its allot slower to place every single wall)
i thought it would be easy just to make a bunch of lines in blender and turn that into a mesh, but apearently its to big or complex for a UV map to work