Problem with lightmaps on adjacent objects


I don’t know if anyone has encountered with such a situation while doing archViz. I don’t know the right way to go about doing the lightmaps when I have walls that stretch more than say 10 meters and are high up to 3-4 meters. If I create a box that is 10 meters long and 4 meters high, then I have to use a very high resolution for the lightmaps like 2048 and up.
If I split up that one big box into 2 smaller boxes (5 meters long by 4 meters high) I can use a smaller resolution for the lightmap, but the boxes become differently lit.
Follow this post to see what I mean:

Has anyone encountered the same problem? Maybe there is a different way to go about working with lightmaps.

You need to construct your objects differently:

I’ve read that wiki, but I haven’t found anything related that would fix my specific problem I’m having.

It’s the same issue–when you separate a flat surface to different objects then the lighting is not going to match up between them.

is there a fix in sight for this different lighting?

No, separate objects are processed on separate threads so it doesn’t share lighting information between them. They did a little research into methods to improve the result but there’s no plans to implement anything.
The best thing to do is avoid situations where that effect will be a problem. Most of the time you will get a better result if the surface is one object anyway.