Translation:It is far from my house.
it's because you are using an i-adjective, 遠い means far and you usually just use desu with these ones
more info here
not really, imagine an implicit topic in the sentence and you will understand why.
仕事は家からとおいです【しごとは いえから とおいです】
You are not talking about your house with the particle から you are talking about something else in relation with your house. The problem is that the "something else" it's usually implicit, in this case you need more context to know what you are talking about it.