I have started a small project, my test map has not been compiled yet so i can't tell u how that will look like, perhaps there mighty troubles compiling so many brushes (i hope not... )
The idea behind this is to speed up level creation and make it more funny and easier than it was before.
My brushes are 128x128 and all of them are grid snapped to each other. One of the most trouble things are corners where one of the wall is going to have different lenght than the "base" modular wall. I think level creating is going to be a three step process:
1) Creating modular brushes depending on the level theme
i think it would be the most time consuming, because u will create hundreds of modular stuff following a theme u need at the moment (underground theme or maybe laboratories), but it might be also the funny time 2) Starting to build a level.
most of that time u will just duplicate modular brushes, and rotate them
3) Placing details, lights, models, prefabs...
detailing the modular level, u should place them wisely, one of the most important thing is "to break modular look and fell" of the map
the article in the link below helped a bit
http://blog.joelburgess.com/2013/04/skyrims-modular-level-design-gdc-2013.html What do u think about this in goldsrc? Is that engine engine and map editor capable to do such things??
ps. if everything goes fine i will post a finished map