"My house is only a mile from here."

Translation: Casa mia è solo a un miglio da qui.

[hammer]

Why is "a" required in this sentence? I don't believe we've learned that construction.

[f.formica]

Well, in English you're omitting "far" or "away", i.e. your house isn't a mile, it's a mile distant; the "a" in Italian serves the same purpose, making mile an indirect object, specifically a place.