Prison Architect Wiki

The Perimeter wall was added in Alpha 13 (Version). Any prisoner digging an escape will always go around a perimeter wall if possible as it takes significantly longer to dig through perimeter squares.

Utilities (Electrical Cable, Large Pipe) cannot be built on perimeter squares as the wall goes very deep underground, any utility lines will be severed when building over them.

Perimeter Wall is one of many types of walls, the others being

  • Fence
  • Brick Wall
  • Concrete Wall
  • Security Walls (Min-sec, Med-sec, Max-sec, White, Yellow)
  • White Wall
  • Tiled Wall
  • Depressing Walls (Rusty, Overgrown, Derelict, Slum, Decayed)
  • Art Deco Wall
  • Oriental Wall
  • Yutani Wall
  • Hedge

Tip: Perimeter walls are typically a mid to late game upgrade after you have enough prisoners to support a decent income and need the extra protection against tunnel digging. Plan for them early by not laying power lines and water pipes where you will be placing them; but in early stages, you can simply put down fencing to save money as your outer wall.

Tip: Similar to fences, if Escape Plans are enabled, inmates can climb over Perimeter Walls using a climbing rope. Prisoners with the Strong Reputation can climb over fences without a climbing rope, but not Perimeter Walls. You can discourage your prisoners from escaping this way by using Barbed Wire, or building a two-tile thick wall.


  • Perimeter Walls are the toughest walls to dig under.
  • Building a perimeter wall will create Paving Stone around the wall.
  • Perimeter Walls do not block contraband by themselves. But using an outer perimeter wall and another inner wall (of any other type) with 10 spaces in between them is enough of a buffer to prevent thrown contraband. Be sure to make the area staff only and have a staff entrance to the buffer area so dogs can patrol for tunnels.