Don't get too emotionally attached to your map. The game is in alpha. You're seemingly playing the game, as are many, as if this is the final game. It is entirely possible as the game gets through beta, and then is actually "released" in full, that some future update will render our current games and maps as unplayable or unable to load at all, and you will be starting over. This was a common and understandable occurrence with alpha and beta games in the past. While people seriously need to get their heads around this possibility, most will not. Most people play alpha and beta games as if they are playing a game that has been released for years, which produces extremely unrealistic player expectations.
Resources are infinite. Building materials are 100% refunded when you destroy something. The maps are huge and space is functionally infinite. You can build higher than you could practically get up to and the lifts make this incredibly easy now. Build with future expansion in mind and if you are having tight space issues, you've already built too small.
In assembly chain games like this it is extremely common to build too tight. Everyone does it when they first start playing these types of games. Spread out, and when you think you have spread out enough, or given enough extra space, double the size. If you want to keep your current map through all the updates that we don't really know anything about, then you'd better future proof your save game by giving yourself tons of room.