Some things I put in our (yet unfinished) Ultimate Horse Barn: very small, heated, well-insulated Bathroom (will tie into house septic system), with sink, water heater, and storage for \"freezeables\" (meds, soaps, etc.); lockable tack room - yours could be for any valuables you want to lock up; feed room, well insulated (frozen sweet feed is a rock), but unheated, just off the main aisleway; wash rack with floor drain (floor drain is actually a box to catch the big stuff, with a removeable cover to clean it out); inside and outside wash racks have hot and cold running water from the bathroom. I insulated as much as I could (4 inches in the walls for the horse stalls; 6 inches in the roof and interior rooms walls). I even built wooden sliding doors with foam insuation in them. Vinyl siding over everything I could, to keep the outside maintenance-free. We built double-pane windows out of pre-cut plexiglass and 2x4s, hinged at the top for ventilation, then corregated clear PVC over that to protect it from UV radiation. Interior is painted gloss white to relect light and keep the spiders from gaining an advantage. All electrical is in either metal conduit, grey PVC conduit (where it goes underground), or in flexible conduit. I will put in more conduit than I think I need, because I will always find a use for it. The biggest thing is to picture the finished product before you pour concrete; think about wall anchors, plumbing, electrical, and how/where it comes out of the floor. Think about how you would repair or replace things - example: put the indoor hydrant inside a 6 or 8 inch pipe, so that when/if you have to replace it, you are not tearing out concrete, but just moving some dirt or rocks. Rich.