From Longman Dictionary of Contemporary Englishbuild something ↔ in phrasal verbTBCBUILDto make something so that it is a permanent part of a wall, room etc You could build in a wardrobe with mirrored doors. → built-in → build→ See Verb table
Examples from the Corpus
build in• The $ 60,000 building opened in 1902 at Eighth Avenue and E Street.• The survey showed that consumer concern about the economy was the single biggest factor affecting the building business in 1993.• Is not it time that he built the economy in a constructive way rather than just waffling about it?• Steve Cooper was standing in an outside doorway of the building he owns in downtown Olympia.• They were built with me in mind and I liked them and got a couple from Fender.• That way you build strength in numbers.• They were built, in steel and chrome, to last - but not quite this long.• So step alone can build some strength in the legs, the study said. 