Translation:The school is cold.
치갑다 means "cold to the touch" while 춥다 means cold when speaking of the weather or the temperature in a room for instanse.
이 의자가 치가요 (this chair is cold [to the touch]) 오늘은 날씨가 추워요! (the weather is cold)
We don't put the object marker 을/를 because the verbs are descriptive (adjectives) and not active (verbs) so they don't need an object. I've used the subject marker 이/가 instead
A better general statement in English would be "Schools are cold."
The general-statement perspective is honestly limited here. "The school is cold." can be translated into Korean as either 학교가 춥습니다 or 학교는 춥습니다.
To determine which translation is appropriate requires context from the conversation. For example:
학교가 춥습니다 is an answer to "What is cold?"
학교는 춥습니다 is answer to "How is school?"
Edit: Top level comment's issue is not with the general-statement aspect, rather improper English. While articles are often dropped in spoken English, they are needed for a grammatically correct sentence.