The farm is the main setting for the whole book, and it is described variously throughout as it changes. At first, it is a working farm, with little place for non-essential things, although Farmer Jones barely takes care of it. His sloth and drunkenness is shown to have had an adverse effect overall:
His men were idle and dishonest, the fields were full of weeds, the buildings wanted roofing, the hedges were neglected, and the animals were underfed.
Despite this, it is shown through the narrative that the animals end up in worse-off at the end simply because they are more exploited by the pigs than by Jones; the farm, meanwhile, becomes more prosperous and larger, since the pigs are able to force the other animals into constant labor.
The farm... had even been enlarged by two fields which had been bought from Mr. Pilkington. The windmill had been successfully completed at last, and the farm possessed a threshing machine and a hay elevator of its own, and various new buildings had been added to it.
(Orwell, Animal Farm, msxnet.org)
Jones could never have afforded the pay for men to build a windmill and new buildings, but the animals work for free and for barely enough food to stay alive. This change in the farm's efficiency somehow does not excuse the animals from working; the new machines and buildings are used to support the pigs instead of supporting all the animals equally. The changes are positive in strict farming terms, but negative for the animals.