There are a number of reasons. The most important reason is that to provide treatment, you need adequate space and adequate facilities to provide the treatment. We need rooms we can deliver groups in. We need private interview rooms. We need to be able to access the offenders for more than an hour and a half a day to provide the treatment we're trying to provide. Some of the older, not purpose-built facilities don't have adequate group rooms. They don't have interview rooms. Because it's a maximum security environment, we fall into the routines of maximum security. An officer comes to a post for a certain period of time but then has to go off and do something else. You can't access the offenders when there aren't officers.
The design of the building has to be conducive to the purpose you're there for. You can't use a building designed for confining offenders to provide treatment, and that's what a lot of the institutions are doing.