There's "Build Mode" but it requires an active ship.
"Design Mode" allows a "virtual design of a ship" in game without the use of resources or limitations, and is ENTIRELY client based. No communicating with servers---just the local machine. Once the design is saved, it can be loaded server side.
Design mode would be a resource independent, client-only (regardless of whether you are on a server), no-ship-required
This would allow a fix for things like:
Having to log off a server to design in single player like a Neanderthal because of server communication time
"You do not have enough slots"
"You do not have access to that building material"
Honestly don't care if I don't have access to that material---I need to get into the ship so that I can fix what's missing/in place so that I CAN build it---without having to log off and go to single player to do it.