The play loft created by putting a ceiling over the bedrooms in the "first house" provides residence for the air conditioning system, but there remains ample play space for train tracks and legos. Since it is a terminal destination, with no through traffic, fantastic constructions can remain in place for days. Here is a view of boys down below playing Baseball on Mommy's I-Phone.
Another view from the play loft across the cupola to the east gable end. The AC duct cozies up to the south side of the cupola.