Quote: the outlets rated for outside now have large plastic covers that snap over them (at least in the states) -- they only partially cover the outlet if you have something plugged in - but are closed when not in use & thereby limit any dust, or etc getting into the outlet plug area. May want to think about using items rated for outside, even if it is inside a barn. GFI's are a must - will pop with any interuption or spike in electricity - now required in any wet areas of any house - kitchens, bathrooms. Sometimes are a pain, as they pop at the slightest mis-step -- but compared to the alternative. Consider putting outlets much higher on the walls than normal - keep the plugs from floor dust animals, etc.. DH is a high voltage electrical worker - I appreciate his over cautions w/respect to power - and everything else for that matter. He's very safe - over-builds, etc - sometimes makes me crazy - but I appreciate it very much.
we also have a fire alarm / smoke alarm system in our house - one of the monitored types, that if set up right, will sound an alarm from the main alarm - very loud - whole neighborhood would likely hear -- but it is on a monitored-type system -not sure how available it might be outside that. think the baby monitor is a good idea for on-the-cheaper. you could set the alarms up in a sequence - if one goes off, they all go off - again, required in new houses here - so if a fire starts in one bedroom, the people in the rooms on the other side of the house get an alarm also. Seems like you could set up a sequence, with one alarm high, in the attic, near a vent in an area directed towards the house -- you'd have to test - not sure if you'd hear through the windows & insulation of a house tho???