Where should one light one’s Chanukia if one lives in an apartment building?

Where should one light one’s Chanukia if one lives in an apartment building?

Lighting outdoors

• The Briatta in Gemara Shabbat 23a states that Chanuka candles should be lit outside by the door of the house. There’s a dispute where one has a courtyard between one’s doorway and the public domain if the candles should be placed by the house door or the courtyard’s entrance to the public domain. Rashi (D”H MeBaChutz) writes that it should put in the courtyard and not public domain, whereas Tosfot D”H Mitzvah argue that it should be placed by the entrance to the courtyard. [The Ran (Shabbat 9b D”H Tanu) agrees with Rashi.] Tur and S”A 671:5 rule like Tosfot that the candles should be placed at the entrance to the courtyard.
• Therefore, Rav Shlomo Zalman Auerbach (Halichot Shlomo 14:4) ruled that if one lives in an apartment building and one is lighting outside then one should light by the entrance to the apartment building unless there is a path leading to the public domain in which case one should light by the beginning of the path near the public domain. [Rav Elyashiv (Shevut Yitzchak vol 5 pg 7) and the Brisker Rav (Piskei Shemuot (pg 41, note 21) agree that even nowadays the stairwell and path is considered a courtyard.] However, the Chazon Ish (Orchot Rabbenu vol 3, pg 3, Piskei Shemuot pg 42 quoting Rav Nissim Karlitz) held that nowadays one may not light by the entrance to a courtyard.

Lighting indoors

• This is all assuming that one is lighting outside. However, the Gemara 23a adds that in times of danger one should light on one’s table indoors. Rashi D”H HaSakana writes that the danger was because the Persians outlawed lighted candles except in the houses of idolatry. This is quoted by the Tur and Shulchan Aruch 671:5 as the halacha. However, the Rama 671:7 writes that the accepted minhag is to light indoors by the door. (For the explanation and defense of this minhag to light indoors see here.)

Lighting by the window or door

• The Gemara 22a explains that one should place the Chanuka candles on the left side of the doorway opposite the mezuzah which is on the right side of the door (as one enters, Rashi). S”A 671:7 quotes this as halacha. Mishna Brurah 671:33 explains that this is done in order that we are surrounded by mitzvot.
• Mishna Brurah 671:38 comments that it’s preferable to light by the window facing the public domain rather than light by the door from the inside. However, Shaar HaTziyun 671:42 adds that this is only when the window in less than 20 amot from the street, otherwise it’s preferable to light by the door. (This is based on the Gemara Shabbat 22a which says that if chanuka candles are above 20 amot it is unfit.) Yalkut Yosef (Moadim pg 198) agrees with the Shaar HaTziyun. However, Rav Shlomo Zalman Auerbach (Halichot Shlomo 14:4) ruled that it’s preferable to light in one’s window even if one is higher than 20 amot from the street because they are seen somewhat from the street and maybe we measure the 20 amot from the floor of the apartment).