According to Jacuzzi, if you add the smartseal insulation package, you will go from paying an estimated $17.75 per month to $11.16 per month. The "smartseal" is just a half inch foil backed insulation that is glued or stapled to the outside skirt of the hot tub. So to answer your question, it can be done and it will save you money. I bought some 2" thick "seconds" that I plan on insulating my jacuzzi with before winter gets here. Take off the panels, apply insulation in any fashion, replace, done.