Yes, outside the bedrooms only is required.
In CT we have adopted a new requirement for CO detectors. If your new construction has any fuel burning appliances, a fireplace or an attached garage, a CO detector must be installed outside the sleeping area. If the house has two sleeping areas, then two interconnected CO detectors are required. AC powered with battery backup, just like smoke detectors. It is probally easiest to purchase combination CO/smoke detectors, and replace the smokie outside the bedrooms.
For re-models or any permitted work (except for exterior only work, i.e. windows, siding, roofing, deck) both smokies and CO detectors must be added at all the locations required for new construction. But, they don't have to be interconnected unless the rooms in question have been gutted, and battery only are permitted. Also, CO detectors for remodels where gutting has not occured may be plug-in types.
The mounting height of the CO detector is not important, as CO disperses throughout the room, and does not settle on the lower portions as CO2 does.