CREATE TABLE FACULTY (Building VARCHAR, FacID VARCHAR)
CREATE TABLE COURSE (Instructor VARCHAR)

Which building does the instructor who teaches the most number of courses live in?
SELECT T2.Building FROM COURSE AS T1 JOIN FACULTY AS T2 ON T1.Instructor = T2.FacID GROUP BY T1.Instructor ORDER BY COUNT(*) DESC LIMIT 1
SELECT "T2"."Building" FROM "COURSE" AS "T1" JOIN "FACULTY" AS "T2" ON "T1"."Instructor" = "T2"."FacID" GROUP BY "T1"."Instructor" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1