Kingsbury, if the house was built in 1990, it is a fair likelihood that the panels are curtain wall or stress skin panels not structural insulated panels ie sips. Typical stress skin panels are composed of laminates of osb on outside, foam core and drywall on inside, such panels are without holding strength (for siding, windowa or just staying attached to the frame) if the decay becomes wide spread. Any building loads imparted to the panels will be carried by the foam core, drywall and siding. So I will stop my imagination from running, proceed with caution, get an onsite consultant.
Edited by Roger Nair (12/30/12 10:51 AM)