A sukka put up to provide shade year-round or never taken down from the previous year is kosher. However, to honor the mitzvah, some sekhakh should be added to it before the holiday.
A person may not build a sukka on someone else’s property without permission, nor on public property if the public or its representatives oppose it. If someone goes ahead and builds a sukka in such a place anyway, it may not be used, since it was not permitted to build it there in the first place.
It is very important to follow fire safety rules in the sukka. Candles must be properly supervised, and electrical connections must be safe. Electric lights must be far enough away from the sekhakh so as not to constitute a fire hazard.
