What contributes to the settlement size limit?

Solution 1:

The size budget is a polygon count designed to keep your frame rate steady by preventing you from building massive and overly complicated settlements. The size limit and current size used are actually attributes against the workbench in the settlement itself and differ between settlements.

This is calculated based on the number of objects in the settlement in combination with the size and complexity of the objects. More complex objects have a higher polygon count and as such use more of the budget. Scrap contributes to this limit so you could "fill" a settlement and then go around destroying all of the broken beds, cups, chairs, etc and have more budget available to build more.

These numbers can be changed using console commands on the PC on a per settlement basis, although it is not recommended.

To get/set the triangle count limit:

• getav 348 - shows the current number of triangles used by the player
• getav 349 - shows the current maximum of triangles usable by the player
• setav 349 - set the maximum triangle limit

To get/set the draw call count limit:

• getav 34A - shows the current number of draw calls used by the player
• getav 34B - shows the current maximum draw call limit usable by the player
• setav 34B - set the maximum draw call limit

Make sure you're looking at the workbench of the settlement when you use these commands.

Solution 2:

There is a way to increase your settlement size without console commands, even on the console versions. My Red Rocket is at nearly 400% capacity on the Xbox One. The game is still handling itself remarkably well, with only the occasional frame missing at the moment and even rarer "game breaking bugs" which force me to a 20-30 minute old save. That said, be careful; I'm obviously pushing the limits on purpose and expect it to break at some point.

Here is how:

1. Place single guns (no stacks) of weapons into your workbench. The more unique guns the better. I use around 20. It can be "10 MM pistol" and "Auto 10 MM pistol" as those are different guns.
2. To streamline the process put all your other guns into a different container.
3. Take the guns out of the workbench and find a flat spot where dropping weapons around you in a circle won't see them get lost.
4. Drop them from your inventory; all at once is fine.
5. Go into build mode and store them in the workshop.
6. Watch your settlement size shrink with each weapon stored.
7. Repeat steps 3-7 until you are satisfied.