I heard about the designing and building option is down, is that true and when are you going to get it up again?

Wait, designing and building what? If you mean R&D of ships/vehicles/weapons/etc. and the production thereof, it's not a case of it being "down", but that those features are not complete and added to the game yet. Production is being worked on and is the next major thing to be added. R&D will be much later down the line after combat.

If you mean construction of facilities, then I haven't heard anything about it being down and if it is, it'll be fixed as soon as they find the bug.