The invention relates to a construction element (8) for erecting a modular green wall comprising a first compartment (10) provided for receiving a planting substrate and irrigation means, the first compartment (10) including an upper portion (10a) provided such as to be facing upward and a lower portion (10b) provided such as to be facing downward, wherein the construction element (8) comprises a second compartment (12) including an upper portion (12a) provided such as to be facing upward and a lower portion (12b) provided such as to be facing downward, and the first compartment (10) and the second compartment (12) are arranged on either side of at least one surface for erecting (P) the green wall and are offset such that the lower portion (12b) of the second compartment (12) covers all or part of the upper portion (10a) of the first compartment (10), or vice-versa.
