Check with the local dudes to see if it's Ok if you have a septic system.
You will also need some air for that furnace to run once you close in that space. Contact your heating guy to help with some answers.If you don't you may...may run into the furnace not running properly and costing you a bit to fix it later...in the middle of winter.
One more thing is the noise in the "sound asleep" part of the night....insulate that wall to keep the level a little lower.
Hope this helps.