Whenever I hover my cursor over a room such as a cell block (not a individual cell) I get limited to doors and gates. I need certain items like a Metal Detector. The area of seems to think it's a room with only the necessity items needed but when in reality it's just a cell block.
I do believe that all objects should be available when hovering inside a cell block (again, not a single cell, but right outside the cell.)
As a irritating issue there should be a verification asking if you are sure you want to build from your plans because there is no cancel build option after you have accidently hit the build plans button. And the defualt answer to verify is 'No' just in case you hit A twice.