If a Jew hires a non-Jewish contractor to build him a house, may the Jew allow the contractor and his laborers to work on Shabbat, or must he instruct them not to perform any building on Shabbat?
The Shulhan Aruch addresses this question in Orah Haim (244; listen to audio recording for precise citation), where he rules that one may allow a contractor to build on Shabbat only outside the town. Strictly speaking, when a Jew contracts a gentile to complete a certain project for a set price, it is permissible for the gentile to perform the work on Shabbat. Since the Jew did not hire him to work specifically on Shabbat, but rather the gentile chose independently to work on Shabbat, no prohibition is entailed. Nevertheless, the Shulhan Aruch forbids allowing the gentile to work on Shabbat in this case within the "Tehum" (the area around a city within which one may walk on Shabbat) of one's city, in order to avoid suspicion. Onlookers may be unaware that the gentile receives a fixed amount, and might assume that he was hired on a daily wage. They might then wrongly suspect the Jewish client of violating the Shabbat laws by hiring a gentile day-worker to perform labor for him on Shabbat.
At first glance, then, it would appear that one may not allow a gentile contractor and his workers to do construction work on his home within the town.
The question, however, arises as to whether this Halacha applies nowadays, when virtually all construction is performed on the basis of a fixed price, rather than a daily wage. Moreover, contractors generally place visible signs at construction sites to inform onlookers of their name and contact information, such that everybody immediately realizes that a contractor has been hired for the project. Seemingly, then, under modern-day circumstances, we need not be concerned that onlookers might suspect the Jewish patron of hiring day-workers to build his house on Shabbat.
Rav Moshe Feinstein (Russia-United States, 1895-1986), in his work Iggerot Moshe (Orah Haim 4:52), rules that technically speaking, it is indeed permissible to allow a contractor to build on Shabbat nowadays even within one's town, for the reason discussed above. Nevertheless, he adds, given the unfortunate laxity with regard to Shabbat observance that is so prevalent in our generation, one should act stringently in this regard. As many Jews are in any event insufficiently committed to Shabbat observance, allowing people to have gentile contractors build on Shabbat might very well lead to graver infringements upon the laws of Shabbat. Most people will not recognize the Halachic distinction between contractors and day-workers, and they might therefore wrongly conclude that it is permissible to hire gentile workers on Shabbat under all circumstances. (We might also add that if other Jews live adjacent to the construction site, the noise of the machinery and trucks will likely interfere with their enjoyment of Shabbat.)
Rav Moshe therefore rules that one should not allow a gentile contractor to build on Shabbat, unless there is some pressing need to do so, in which case one should consult with a Rabbi for guidance. Rav Shemuel Pinhasi (contemporary scholar in Israel) reaches a similar conclusion in his work Ve'daber Davar (listen to audio recording for precise citation). He adds that even if the Jew wrote in the contract that he does not require the contractor to work on Shabbat, he may not allow the building to continue on Shabbat. Rav Pinhasi writes that outside the city there is room to allow the construction to be performed on Shabbat.
Some years ago the Reichman family embarked on a multi-billion dollar building project in Battery Park in Manhattan, which received a good deal of attention and notoriety, and they instructed the contractors to refrain from building on Shabbat. This created a great Kiddush Hashem (sanctification of God's Name) as it impressed upon people the importance of Shabbat observance, and this serves as an inspiring example for us to follow.
Summary: One should not allow a gentile contractor and his workers to build on Shabbat; in situations of dire necessity, one should consult a Rabbi for guidance, as under some circumstances there may be room for leniency in this regard.
