937. Building the Succah on the Day After Yom Kippur

133:31 On the day after Yom Kippur, the practice is to go to shul early. On the days between Yom Kippur and Succos, we do not fast, not even for a Yahrzeit.  We also do not say Tachanun on these days because they are days of joy, during which they prepared the Temple's altar in the time of King Solomon. We also occupy ourselves with such mitzvos as building the succah and acquiring the esrog and the other species in order to honor G-d, Who sanctified Israel and the Festivals.

134:1 It is a mitzvah to build the succah immediately on the day after Yom Kippur. This is true even if it's a Friday (until midday - Mishnah Brurah 625:2) because if one has the opportunity to fulfill a mitzvah, he should not let it pass by. One should find a clean place to build his succah. Everyone is obligated to personally involve himself with building the succah and putting on the schach (the covering used for a roof). Even an important person must do so and it is to his honor that he involves himself in the mitzvah. Really, we should recite the bracha of shehechiyanu over building the succah but our practice is to rely on the shehechiyanu that we say in kiddush.  One should beautify his succah, adorning it with beautiful utensils and coverings according to his means.