DH and I have been scanning the internet for barn designs. We have 12 acs in another county where we spend a lot of time and would like to take the horses. He likes a Monitor style - we need a loft to have a "room" where we could stay. He is very handy and can do a lot of the work - I have a lot of experience helping. We are thinking 3 stalls, tack room and wash stall... Deck to the loft so the stairs would be outside.
As convenient room over a barn for habitation seems, do consider making the main human dwelling on the bottom, as injuries or age can make stairs a severe handicap.
Only you know if that will some day may be a concern you need to provide for now.
Good friends have a barn/2 BR apt all on ground level. The apt has a front door and screened porch on the side facing the arena. You can access to the apt. through the tack room, also. The floor plan is very logical, and comfortable to live with.
that it is legal --some place require free standing primary residence prior to apt. being built, some place illegal not to have caregivers on site w/horses (yes I know most folks work and ponies alone all day but still check) . klr