The sukka is sanctified for the purpose of the mitzva, for it is written: “There shall be the seven-day festival of Sukkot to the Lord” (Vayikra 23:34). Thus, throughout the festival, one may not use any part of the sukka, whether from the sekhakh or from the walls (Sukka 9a). The Sages further prohibited using any of the sukka decorations designated for beautifying the sukka, for since decorating is also a mitzva, the decorations are set aside for that mitzva. Even if the sukka collapses, it is forbidden to use its broken parts and decorations until after the festival. Moreover, since the prohibition persists until the end of the seventh day of Sukkot, including bein ha-shmashot, which is also the beginning of Shemini Atzeret, it consequently remains prohibited until the end of Simḥat Torah (Beitza 30b; SA 638:1-2).
However, since the sukka is a residence, one may use the walls and sekhakh in the way that one would normally use the walls and ceiling of his home. Thus, one may lean against the wall of the sukka and hang items on it, and one may hang a garment to dry from the sekhakh (Sukka 10b). The prohibition applies only to taking something from the sukka and using it, for example taking a beam from the sukka to build something else or even pulling off a splinter to use as a toothpick (Rema 638:1; MB ad loc. 4). It is also forbidden to remove the wall hangings, the decorations, or the fruit hung from the sekhakh in order to use them for some other purpose. One may not even move them without cause, as doing so detracts from the sukka and its decor. Carpets and floor tiles have the same status as decorations, as they have been set aside for the mitzva of sukka (Igrot Moshe, OḤ 1:181).
If a decoration or part of the sukka becomes bothersome, for instance, if a beam is loose and creaky, or a decoration has fallen apart and is making the sukka ugly, one may remove and dispose of it respectfully, but it may not be used for something else.
If rainfall threatens to ruin the decorations, one may take them down to rehang them later. If one obtained nicer decorations during the festival, he may remove the old ones to replace them with the nicer ones, as long as he does not use the old decorations for another purpose, as they were set aside for mitzva use.
If one wants to be able to derive benefit from his sukka decorations during the festival, he should make the following declaration before the festival begins: “I hereby stipulate that I may remove and enjoy these decorations whenever I want, and that they do not become sanctified.” One cannot make such a stipulation about the sukka itself (Beitza 30b; SA 638:2).
A sukka may be taken down to be rebuilt elsewhere. The prohibition of muktzeh forbids using the sukka beams for a different purpose, but using them in another sukka is permissible.
With the end of the festival, the sanctity of the decorations, walls, and sekhakh expires. One may use them for any mundane purpose, but one may not degrade them, for instance, by using the paper as toilet paper or stepping disrespectfully on the sukka beams (SA 664:8; MB 638:24).
The sukka and its decorations become muktzeh from the moment one begins to use the sukka (Rema 638:1). In practice, however, even if the sukka has not yet been used, they may not be moved on Shabbat and Yom Tov and are muktzeh due to the prohibition of Soter (Mor U-Ketzi’a; BHL 638:1 s.v. “lo”).