I added this info which I got from a website;

BIGBANG is divided into 2 apartments so each of them has their own rooms. GD&SEUNGRI together, then it used to be TOP, DAESUNG & YB but we all know TOP moved out and bought his own house in latter half of 2010. recently, there’s news that GD has bought his own apartment late last year and he mentioned moving back with his family late last year during his hiatus. idk if GD lived with his family while he’s going through his scandal and he’s back living with Seungri now or on his own. the news mentioned him buying a unit at the same apartment complex where YG’s renting but i know fro 2ne1/BBtv that their dorms are at the same apartment complex too. maybe he just bought the same apartment unit they’ve been living at? lol the only thing we’re sure of is YB& DAE still live together

v TOP always mentions coming from his house in BTS vids though? like when they were preparing for BigShow 2011. He even keeps making excuses about his house being farther and traffic when they were doing that late penalty.

New info added (22 May 2012):

All members except TOP live at the dorm now. 

New info added (21st Dec 2012):

Taeyang, Daesung and Seungri moved in to a new apartment, just one floor below GD's own apartment. TOP is still staying at his own villa with his family. 

New info added (25th July 2013):

Taeyang got a place of his own now according to Vogue Korea Living Magazine spreads, which shows the interior of his house. Maknaes are still living together at the apartment below Jiyong's apartment supposedly, perhaps Taeyang frequent at the apartment too as it is their dorm now.