집으로 the letter before 으로 has 받침 like ㅂ in 집
학교로 without 받침 you'll use 로
The usage of 로/으로 is various
1.Showing direction of movement, change like preposition to,etc. in English
학교로 갔다 went to the school
악마로 변했다 changed to the devil
2.Means,way like with,by,in,etc.
칼로 자르다 cut with a knife
현금으로 지불하다 pay in cash
3.Material,ingredients for making things like of,from.etc.
쌀로 만들어졌다. made of rice
나무로 지어졌다. built of bricks
4.Position,rank like as
대통령으로 뽑히다 elected president
5.Cause
암으로 죽다 die of cancer