How does Squealer justify the pigs' move into the farmhouse in George Orwell's Animal Farm?
When Squealer informs the other animals that the pigs are going to move into the farmhouse, he phrases it very specifically:
It was absolutely necessary…that the pigs, who were the brains of the farm, should have a quiet place to work in.
This is an example of a propaganda technique Squealer uses on several occasions. This technique has two functions; it plays on the popular conception that the pigs are the most intelligent animals on the farm and acts as an emotional appeal which makes the animals think allowing the pigs to live and work in the farmhouse will benefit everybody.
In reality, the pigs are moving into the farmhouse because they want to live in a more comfortable environment but want it to appear like a necessary move, not a selfish one. In the longer-term, however, this move separates the pigs from the other animals, making their rise to absolute power an inevitability.
You can find the answer to this question in Chapter 6. Basically, Squealer tells all the other animals that this move is necessary for their own good.
The way that this is for the good of the other animals is that Napoleon really needs to live in the house to be able to run the farm well. That will help the other animals because it will make their lives easier.
Squealer also says, though, that Napoleon should sleep inside the house because that is more dignified and the leader should have dignity.
So Squealer justifies it partly on the grounds that it will help the whole farm and partly on the grounds of how important Napoleon is.