A. Next door to our school a house is being built by them.
B. Next door to our school is being built a house by them.
C. A house next door to our school is being built by them.
D. A house is being built by them next door to our school.
Given sentence is in present continuous tense and it is in active voice.
Rule :
Subject + (is /am /are) + being + V3 + Other agents.