Civil Code (Cap. 16), article 419

419. It shall not be lawful for one of the neighbours - (a) to make, without the consent of the other neighbour any cavity in the body of a common wall; (b) to cause any new work to be affixed to or to lean against a common wall, without the consent of the other neighbour, or, in case of his refusal, without having first determined by means of experts the necessary measures to be taken in order that the new work shall not injuriously affect the rights of the other neighbour; (c) to deposit manure or other corrosive or damp substance in such a manner a s to be in contact with the common wall; (d) to heap earth or other matter against a common wall without taking the necessa ry precautions in order to prevent such heaps from causing, by pressure or otherwise, damage to the other neighbour. 136 [CAP. 16. CIVIL CODE Repairs to walls separating courtyards, etc.