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

==Placement indoors according to the Gemara==
* The Briatta in Gemara [[Shabbat]] 23a states that Chanukah 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 s.v. Mitzvah argue that it should be placed by the entrance to the courtyard. [The Ran ([[Shabbat]] 9b s.v. 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. 
* Rav Shlomo Zalman Auerbach (Halichot Shlomo 14:4) ruled that a stairwell is considered a courtyard, therefore, if one lives in an apartment building and one is lighting outside, 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) held that nowadays one may not light by the entrance to a courtyard. (See further). 
===Is it better to light by the window or by the door outside?===
* Rav Nissim Karlitz (nephew of the Chazon Ish, Chut Sheni Chanukah pg 306-7) explains the position of the Chazon Ish as follows: nowadays one may not light in a courtyard since the courtyards aren’t used as part of the house as they were in the times of the Gemara. Rather one should light at one’s door unless people won't see it in which case one should light in the window facing the public domain. Yet, if the window is above 20 [[amot]]  from the street it’s preferable to light at the entrance of one’s door towards the stairwell which is used by a few tenants instead of lighting on one’s table.
* Similarly, Torat HaMoadim (Rav Dovid Yosef, 2:2, pg 74-6) also rules that it's preferable not to light by the entrance of the stairwell since nowadays our courtyards aren't used the same way they were used in the time of the gemara. Therefore, he writes it's better to light by the window facing the public domain and if it's above 20 amot, one should light by the door of one's apartment. [Torat HaMoadim infers from the writings of his father, Rav Ovadyah Yosef, in Kol Torah (5725 Kislev) and Yalkut Yosef (Moadim pg 198) that he agrees with the Chazon Ish (see there for further detail).] Or Letzion v. 4 p. 243 agrees with the Chazon Ish.

==Placement indoors according to the common minhag==
* This is all assuming that one is lighting outside. However, the Rama 671:7 writes that the accepted minhag is to light indoors next to the door. (The Gemara 23a writes that only in times of danger one should light on one's table indoors. Rashi s.v. 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. Nonetheless, the minhag is to light indoors even though it's not dangerous outside. For the explanation and defense of this minhag to light indoors [[Placement_of_the_Chanuka_Candles#Placement_of_the_Chanukia| see here]].) 
===Where to light inside the home===
* The Gemara 22a explains that one should place the Chanukah 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) and Rav Nissim Karlitz (Chut Sheni Chanukah pg 307) agree with the Shaar HaTziyun.
* Rav Shlomo Zalman Auerbach (Halichot Shlomo 14:4 and note 22) 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). He acknowledges that some say that one may light in an apartment building above 20 [[amot]] from the street because there are apartments across the street who can see it. Even though he felt that this last explanation wasn't sufficient he still ruled the way he did based on the Pri Megadim who plainly argued on the Shaar HaTziyun. Chazon Ovadia Chanuka p. 39 wrote that one can light above 20 amot if there is a building across the way and that is preferable to lighting inside.