1,180. Succah Decorations

Hilchos Shofar, Succah v’Lulav 5:17

If a person spread a cloth over his schach, or beneath it to catch debris, the succah is invalid. If he spread it lower, as a form of decoration, it is valid. Similarly, if one covered his succah with valid schach and then decorated it by hanging fruit or other items from the walls or the schach, it is valid.

Hilchos Shofar, Succah v’Lulav 5:18

Decorations do not reduce the height of a succah but they do reduce the width. If succah decorations are removed four or more handbreadths (about a foot) from the roof, it is invalid because it’s like one isn’t sitting under the schach but under the decorations, which are things that are not valid for use as schach.