(a) All foundations of every dwelling structure shall be maintained in structurally sound condition and in good repair.
(b) All foundations of every dwelling structure shall be maintained in such condition as to prevent seepage or leakage of water into the space enclosed within such foundations.
(c) All openings into the foundations of every dwelling structure shall be protected against the entrance of rodents.
(d) Where parts of dwellings supported on masonry piers require substantial repair or replacement due to sagging, settling, or failure of supporting piers, the same shall be replaced with a foundation conforming to the Building Code of the City.