May one build a Sukkah in someone else’s property without permission?[1]
Initially, one may not build a Sukkah in someone else’s property without their permission.[2] [This applies even if the person will not be present there throughout Sukkos.[3] Thus, if a neighbor is leaving town, one may not use their property to build one’s Sukkah without explicit permission.]
[1] Admur 637:10; Rama 637:3
[2] The reason: As perhaps the owner of the land minds that one is building a dwelling place in his property without his knowledge, as we do not say one does not mind a Mitzvah being done with his property unless it is done for temporary basis and not when he is using his money on a permanent basis. [Admur ibid; 14:10]
[3] Implication of Admur ibid; Bach 637; P”M 637 A”A 7; Piskeiy Teshuvos 637:3