build onto (something)(redirected from building something onto something)
build onto (something)
To use something as a foundation and expand or construct additional elements to it. A noun or pronoun can be used between "build" and "onto." This kitchen is far too small—we'll need to build an addition onto it. Many were opposed to the city's plan of building onto the ancient church.
See also: build
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.