The European sound /g/ is transcribed differently in different Arab countries. In Egypt, we'd spell the word جراچ, because Standard Arabic /dʒ/ is pronounced /g/ in Egypt. In the Gulf, we'd use ق, so we'd spell it قراج, because Arabic /q/ is pronounced /g/ in the Gulf. In the Levant, we'd spell it غراج, in Morocco, ڭراج, and in Tunisia, ڨراج.
When you do adjectives in arabic don't you always put the wa between each adjective, so when you translate to English you put the adjectives as we go in English.
I think it depends on whether the adjectives "intersect" or not. Like how in Spanish, if you say "un amigo viejo" ("an old friend"), the person you're describing happens to be both a friend and an old person, but the oldness doesn't describe the friendship itself, he could be a new friend. But if you say "un viejo amigo," you mean a friend whose friendship has lasted for a long time. Likewise, if you think the bigness and the coldness of the garage are somehow related, that the fact that it is big is the reason that it is cold or vice verse, you wouldn't use the و, but if it simply happens to be both cold and big, but could become small, and the coldness wouldn't be affected, or hot, and the bigness wouldn't be affected, you would. Hope this helps! ;)