Wiktionary
underbuild
vb. 1 (context transitive English) To build beneath another structure; provide a foundation or support for; undergird. 2 (context transitive English) To perform insufficient construction on a building or in an area; build below a specified requirement or standard.
Usage examples of "underbuild".
He conducted Forrester through underbuilding mazes and footbridges Forrester had not even seen, his mouth going all the while.
Forrester took five dollars from a pretty girl in a sort of mirror-bright bikini, then fifty from a man who had brought his pet animal—it was a little silk-furred monkey—down to the underbuilding park to run free, and who seemed to accept Forrester’s touch as a form of rent for the use of the premises.