It really srews you over if you planned everything ahead. In many other guides, I read this and made the mistake of creating 5x4 buildings rather than 7x4 to accomodate for walls.
Note: When I mention room dimensions (eg 5x4), I am refering to the inside of the building. Just keep this guideline in mind when contructing these buildings: 'This is only the beginning, don't close yourself in with the first rooms!' Make sure to have room for expansion and plan ahead! It is advisable to have either a grid system of building (where you have blocks of four buildings with paths inbetween) or a central path system (where you design your buildings around a central path, usually two squares wide, with branches of square-wide paths sprouting off it leading to other sections) (hint: there is a planning tool). You will build the required buildings for the first two grants (these being Administration Centre and Basic Detention Centre). The layout of a new prison is super important because it will set the trend and direction of your growing prison.
