If I make a vow to keep a kosher kitchen but later sell my home to Gentiles who will not keep kosher in my old kitchen do I need to say Hatarat nedarim since the kitchen I owned when I made the vow is no longer kosher? Or does the vow carry over to my new kitchen in my new home, which I plan to keep kosher?
ב"ה The type of vow you made is a special type of vow. Since every Jew is obligated to keep the Torah since he was already sworn in at Mt. Sinai to fulfill the mitzvoth of the Torah, the vow stringency you took upon yourself is an additional to uphold the Torah and make your observance more binding which is a permissible thing. King David himself said in Tehillim "I have sworn and I adhere to it to keep your righteous precepts". (See Tehillin 119:106, Talmud Nedarim 8 a, Shulchan Aruch Y.D 203:6, Kitzur Shulchan Aruch chapter 67). Therefore, a Hatarat Nedarim is not applicable, since in any case you are obligated to keep kosher which you will now do in your new kitchen as you yourself said. The kitchen you meant to keep kosher is the one in your possession, not one which is now in the hands of a gentile. May Hashem bless you to continue your pursuing of fulfilling mitzvoth for many more years to come.