Big meshes problematic?

Hello, i was wondering if big meshes were a problem in term of optimization. of course i’m talking of non complex meshes here. let’s say 100 x 50 x 1 m, but only 500-600 polys

If you use baked lighting then you have one lightmap for a static mesh, so if it’s very large then the lightmap may not have enough detail even at a high resolution.

i’m using dynamic lighting (no UV map)