Underpinning p. pr. & vb. n. : of Underpin

Underpinning n. : The act of one who underpins; the act of supporting by stones, masonry, or the like.

Underpinning n. : That by which a building is underpinned; the material and construction used for support, introduced beneath a wall already constructed.

Underpinning n. : The foundation, esp. of a frame house.

Example:
what do I do if my Underpinning overlaps by just a few inches on my mobile home?

Taxonomy
Underpinning, foundation, soil, Sketch, free encyclopedia, the foundations, original foundation, needle beam, piers, piles, search, stable, mischaracterized, nearby structures, land price, new one, breadth, rests.

Defination from the web:
underpinning is the process of strengthening and stabilizing the foundation of an existing building or other structure. ... Underpinning is accomplished by extending the foundation in depth or in breadth so it either rests on more supportive soil stratum or distributes ...