סימן עג סעיף ו

אִם בָּנוּ גוֹיִם לְיִשְֹרָאֵל בַּיִת בְּשַׁבָּת בְּאִסוּר, נָכוֹן לְהַחְמִיר שֶׁלֹּא יִכָּנֵס בּוֹ (וְיֵשׁ בָּזֶה כַּמָּה חִלּוּקֵי דִּינִים).

If a non-Jew built a house for a Jew on Shabbos, in violation (of the aforementioned Halachos), it is proper to be scrupulous¹⁶If he worked on a contractual basis and within the techum you are allowed to move in, but it is proper to refrain from using it. However, if he worked and was paid by the day you are prohibited from using it [Bach, Magein Avraham, Chayei Adam, Mishnah Berurah 244: 19]. If you gave the non-Jew work on a contractual basis, and it is within the techum, you must make it conditional that he not work on it Shabbos. If he breaks this clause and works on Shabbos, the Mordechai and the Vilna Gaon rule that you need not even attempt to stop him. The Mishnah Berurah 244: 22 rules like the Magein Avraham (and Eliyahu Rabbah, that you should protest, but you do not have to pay him to stop working on Shabbos. If you failed to make this condition you may be required even to pay money to prevent him from doing the work on Shabbos [See Mishnah Berurah, Biur Halachah 244: 22]. and not move into it. (This Halachah has many details.)

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.)