סימן קיא סעיף יב
חֶדֶר שֶׁצָּרִיךְ בְּדִיקַת חָמֵץ, וְרוֹצֶה לַעֲשׂוֹתוֹ אוֹצָר, פֵּרוּשׁ שֶׁרוֹצֶה לֶאֱצוֹר בְּתוֹכוֹ פֵּרוֹת אוֹ עֵצִים אוֹ שְׁאָר דְּבָרִים, שֶׁמֵּחֲמַת זֶה לֹא יוּכַל לְבָדְּקוֹ, כְּשֶׁיַּגִּיעַ לֵיל אַרְבָּעָה עָשָׂר, צָרִיךְ לִבְדּוֹק תְּחִלָּה אֶת הֶחָמֵץ שָׁם בַּלַּיְלָה, כְּמוֹ שֶׁבּוֹדְקִין אֶת הֶחָמֵץ לֵיל אַרְבָּעָה עָשָׂר. וַאֲפִלּוּ יֵשׁ עוֹד זְמַן רַב עַד הַפֶּסַח, וַאֲפִלּוּ מִיָּד לְאַחַר פֶּסַח שֶׁעָבַר. וּבְדִעֲבַד אִם לֹא בְּדָקוֹ קֹדֶם שֶׁעֲשָׂאוֹ אוֹצָר, אִם דַּעְתּוֹ לְפַנּוֹתוֹ קֹדֶם שֶׁיַּגִּיעַ זְמַן בְּדִיקַת חָמֵץ, אֵינוֹ צָרִיךְ לִטְרוֹחַ עַתָּה לְפַנּוֹתוֹ וּלְבָדְקוֹ. אֲבָל אִם דַּעְתּוֹ לְפַנּוֹתוֹ בְּתוֹךְ יְמֵי פֶּסַח, צָרִיךְ לְפַנּוֹתוֹ עַתָּה וּלְבָדְקוֹ, וְאַף עַל פִּי שֶׁיֵּשׁ טֹרַח רַב וְחֶסְרוֹן כִּיס.
If you have a room that must be searched, that you want to use as a storage room; that is to say, you want to store, fruit, wood or other articles, which would make it impossible to search the room on the night of the fourteenth of Nisan, then you should search that room before11Regarding a person who embarks on a journey before the night of the fourteenth, who is required to search his home before leaving, Mishnah Berurah writes that he must also nullify the chametz that is not visible to him. (This may also apply in our case as well). (Ibid. 436:3) you convert it to a storeroom, making the search at night,12Regarding a person who embarks on a journey before the night of the fourteenth who is required to search his home before leaving, Mishnah Berurah writes that if he forgot to search at night, he should do so by day. (Ibid.) in the same manner as you search for chametz on the night of the fourteenth of Nisan.13However, the berachah is not recited when the search is made before the night of the fourteenth. (See Mishnah Berurah 436:4 and also Biyur Halachah who writes that there are opinions that a berachah is said when the search is made within thirty days of the fourteenth). [This holds true] even if there is still plenty of time before Pesach, and even if this is immediately after the Pesach that has just passed. However, if you did not search the room before turning it into a storage room, if you intend to remove the stored articles, before the time of the search will come, you do not have to go to the trouble at this time to empty the room and search it. But if you intend to remove the articles during the week of Pesach, you must remove them now and make the search, even though it involves great trouble and loss of money.
תנא דבי אליהו כל השונה הלכות בכל יום מובטח לו שהוא בן העולם הבא שנאמר הליכות עולם לו אל תקרי הליכות אלא הלכות (נדה ע"ג.)