Ok guys, so I want to get something off my chest as far as this whole map project goes: While I think gm_constuct worked for gmod up to this point, as far as an environment goes, it could be much more for the players. I have not played gmod in years, but I still think about these kinds of projects, what players want/need out of their environment, and how maps can provide that.
If players of gmod want a space conducive to building, they'll play flatgrass, so while flatgrass exists, construct cannot compete by merely being some place to build. Gmod 13 needs a map with a fun and experimental atmosphere for players to actually play in, invent games, and interact using the environment as a guide. We need to design with fun in mind, and that's where this concept comes from.
things gm_construct needs to be successful:
open space
sectors divided for privacy
playful environment
visual variance
easy player transportation
easily readable environment
visual identity
happy atmosphere
One environment theme able to tick most any of these boxes is the outside of a typical highschool.

(just a visual aid, not a layout or anything)
open space-(parking lots/fields are great for building)
sectors divided for privacy-(fences, gates, buildings(inside the gym, inside the garage))
playful environment-(drivers ed lot outlines, football field, baseball field, soccer courts, basketball courts, pool/lake, running track, etc)
visual variance-(grass qualities, parking lot spaces, astroturf, concrete sidewalks - all these elements help break up and detail the environment without adding useless noise, these elements help define space for its size and use as well)
easy player transportation-(as long as the player knows the layout(maps can help guide) and there is a common path connecting sectors)
easily readable environment-(everyone in our audience understands highschools, their general layout, and all that entails)
visual identity-(this idea hasn't be done in gmod, to this extent at least)
happy atmosphere-(bright sunny day, bugs/birds chirping, colorful lawns, high school memories)
I think this could be a great jumping-off point for facepunch's many designers, and something players of the game could use. I understand that this concept really sucks as far as content reuse goes, but I think the end result could be worth the effort. I really just want to motivate facepunch into making something better than a refreshed construct. Sorry for being a total ideas guy, I would actually be working on this project by myself if I didn't already have engagements. If you guys think it's a good concept to start with, go for it.