Should you make an addition to a mobile home that is only on a gravel pad?

no, probably not. The addition will have to be to code (which depends on your location) may or may not require a foundation. If there is any possibility of movement on the exisiting structure (there will be) will cause cracking drywall, stuck doors and Windows, possibly even structural damage.

AnswerIf your home was properly installed in the first place and the blocks are set and your tie downs are in place, you can build an addition. In most places as long as it subject to HUD code the addition must be free standing.

The theory is that with frost heave your home will move. Well if your foundation,{blocking and gravel pad} doesnt freeze why would it move?

If your "skirting" were insulated well,and your Foundation were not to freeze,your addition, if built well and not subject to freezing, why should it move?

Many people build garages that appear to be attached to the manufactured home but actually is not.

I manage a large manufactured home community in the upper Midwest and many manufactured homes on a gravel pad have successful additions.

spend the money on a house.