An existing mobile home in upstate NY is attached to a slab-on-grade foundation, an existing addition to the mobile home is on floating pier foundations (above frost line), and a new addition is being built. The local building inspector is requiring the new addition to be built on piers with footings below frost line (48") and says NY state no longer allows any floating pier foundations. In my opinion, there will be serious problems when the existing structures move as the ground freezes and thaws, and the new addition doesn't move. My feeling is that the new addition should be built on floating piers above the frost line to match the existing structures. Any ideas or suggestions?

Well, your local inspector is correct in that NY state building code now requires that mobile homes and all additions to them be placed on permanent foundations no different than a conventionally built house.

But there may a problem in connecting the addition to the mobile home built on a permanent foundation with the existing slab but the code also addresses this.

For example some code sections applying to mobile homes and this situation read:

"AE502.3 FOOTINGS AND FOUNDATIONS. Footings and foundations, unless otherwise specifically provided, shall be constructed of materials specified by this code for the intended use and in all cases shall extend below the frost line."

"AE504.1 GENERAL. Accessory buildings shall not be structurally supported by or attached to a manufactured home unless engineering calculations are submitted to substantiate any proposed structural connection.

EXCEPTION: The building official may waive the submission of engineering calculations if it is found that the nature of the work applied for is such that engineering calculations are not necessary to show conformance to these provisions."

The bottom line is that the building code official is given a fair amount of latitude to determine either by engineering calculations or by observation what should be required for the construction and connection of the mobile to any accessory structure, but under no circumstance can the new structure be constructed without frost footings by NY state building code.

It appears that your local inspector has made the right judgement call given the imperfect situation.

This message has been edited. Last edited by: homebild,