Shulchan Arukh Orach Chayim · Siman 641

English

1. The Blessing Shehecheyanu is Not Recited over the Construction of a Sukkah: One who constructs a sukkah, whether for himself or for someone else, does not make a blessing upon its construction. Shehecheyanu is appropriate to be said when one constructs a sukkah for himself. However, we rely on the blessing Shehecheyanu that we recite during Kiddush on the [first] night of Yom-Tov that [is recited] because of the mitzvah of sanctifying the festival, which is also a mitzvah that comes [only] periodically. (The one blessing covers both requirements). RAMA: If one does not eat in the sukkah on the first night, even though he sanctifies the festival in his house, when he does eat in the sukkah he must sanctify the festival due to the sukkah. If he sanctifies the festival at the time of construction of the sukkah, it is sufficient for him [R"an].