Mishnah Oholot 14:1: A protrusion spreads impurity in any size, a balcony and a canopy with a handbreadth's space. What is a protrusion? That which has its face [surface meant for use] down. And a balcony? That which has its face upward. When did they say the protrusion spreads impurity in any size? When the protrusion is three rows of stones above the opening which is twelve handbreadths. More than that, it spreads impurity with a handbreadth's space. Crowns and engravings spread impurity with a handbreadth's space.

הַזִּיז מֵבִיא אֶת הַטֻּמְאָה כָּל שֶׁהוּא. הַגִּזְרָה וְהַגַּבְלִית, בְּפוֹתֵחַ טֶפַח. אֵיזֶהוּ הַזִּיז, שֶׁפָּנָיו לְמַטָּה. וְהַגִּזְרָה, שֶׁפָּנֶיהָ לְמָעְלָה. וּבַמָּה אָמְרוּ הַזִּיז מֵבִיא אֶת הַטֻּמְאָה כָל שֶׁהוּא, בְּזִיז שֶׁהוּא גָבוֹהַּ מִן הַפֶּתַח שְׁלשָׁה נִדְבָּכִין, שֶׁהֵם שְׁנֵים עָשָׂר טֶפַח. יָתֵר מִכָּאן, מֵבִיא אֶת הַטֻּמְאָה בְפוֹתֵחַ טֶפַח. הָעֲטָרוֹת וְהַפִּתּוּחִים מְבִיאִין אֶת הַטֻּמְאָה בְפוֹתֵחַ טָפַח:

Mishnah Oholot 14:2: A protrusion which is on top of a doorway spreads impurity in a handbreadth's space. One on top of a window two fingers high or on top of the thickness of a drill, [spreads impurity in a space that is] any size. Rabbi Yossi says [it spreads impurity in a space that is] its [the window's] thickness.

זִיז שֶׁעַל גַּבֵּי הַפֶּתַח, מֵבִיא אֶת הַטֻּמְאָה בְפוֹתֵחַ טֶפַח. שֶׁעַל גַּבֵּי הַחַלּוֹן, רוּם אֶצְבָּעַיִם, שֶׁעַל גַּבֵּי מְלֹא מַקְדֵּחַ, כָּל שֶׁהוּא. רַבִּי יוֹסֵי אוֹמֵר, מְלֹאוֹ: