Is door jamb area included in carpet area

Q: Builder is asking extra money for door jamb area equivalent to 10 sqft increase in saleable area. this has come after revision in the plan. Before revision the carpet area was 473 sqft w.r.t saleable area of 686 sqft. Now the carpet area has become 479 sqft and saleable area 695 sqft. My question is that looking into the roomwise dimensions notified in the builders plan the difference is coming in -ve i.e. less by 1sqt in carpet area. then how come the builder is demanding for door jamb area, whereas earlier before revision of plan this same door jamb area would have been considered. kindly give your valuable advise on this matter.