111:11 Even though we nullify the chometz at night after the search, we nullify it again in the day after burning it. One should include all his chometz and say Kol Chamira or the equivalent in a language he understands: “All leaven and chometz that is in my possession, whether or not I have seen it, whether or not I have removed it, should be annulled and be like the dust of the earth.”
111:12 If a room requires searching for chometz and one wants to use it for storage, such as to store produce, wood or other things that will cause him to be unable to check it on the night of 14 Nisan, he needs to check it for chometz at night the same way that he would on the night of 14 Nisan (albeit without a bracha – Mishna Brurah 436:4). This is the case even if Pesach is a long way off, even if it’s right after the previous Pesach. (He must also recite the nullification of chometz at that time – MB 436:3.) After the fact, if one did not check the room before using for storage, if he intends to empty it out before it is the time to search for chometz, then he need not trouble himself now to empty it out and check it. However, if his intention is to empty the room out over Pesach, he must empty it now and check it, even if doing so is a lot of work and causes him a financial loss.