As the undisputed political elite in Oceania, members of the Inner Party get to live in luxurious accommodation, at least by comparison with the rest of society. As well as being provided with spacious living quarters, servants, good-quality food, and consumer goods, the Party elite also enjoy the special privilege of being able to turn off their telescreens.
Outer Party members such as Winston Smith are not quite so fortunate. They live in cramped, dilapidated accommodation that reflects their relatively lowly position in the state. Winston's tiny apartment is pretty much falling to pieces, with plaster coming off the walls in flakes and a leaky roof. To make matters worse, it's often freezing-cold as the heating never works at full throttle, and it takes ages to carry out repairs due to bureaucracy. Winston's miserable, sparsely-furnished, inhospitable dump of an apartment epitomizes the oppressive conditions in which he and the vast majority of citizens are forced to live.
As for the Proles, who constitute 85% of the population of Oceania, they live in rundown Victorian housing, generally left to their own devices by the state, as they're not perceived as a threat to the regime. The dilapidated state of their accommodation symbolizes the attitude of neglect that the Party has towards them. So long as the Proles work and breed, it doesn't matter to the Party what kind of ratholes they live in. As for the Proles themselves, they don't seem to mind all that much, so long as they're regularly supplied with copious amounts of beer, sex, and lottery tickets. Unlike members of the Outer Party, however, the Proles are not required to have telescreens in their run-down hovels. They can buy them if they want, but as they're prohibitively expensive, hardly anyone does.