31 Del. C. ch. 41 § 4116

(a) In general. — Every dwelling unit shall include its own plumbing facilities which are in proper operating condition, can be used in privacy and are adequate for personal cleanliness and the disposal of human waste.

(b) Water closet and lavatory. — Every dwelling unit shall contain a lavatory and a water closet supplied with cold running water. The water closet shall not be located in a habitable room. The lavatory may be placed in the same room as the water closet, or, if located in another room, the lavatory shall be located in close proximity to the door leading directly into the room in which said water closet is located. The lavatory shall be supplied with hot and cold running water.

(c) Bathtub or shower. — Every dwelling unit shall contain a room which affords privacy to a person in said room and which is equipped with a bathtub or shower supplied with hot and cold running water.

(d) Sink. — Every dwelling unit shall contain a kitchen sink apart from the lavatory required under subsection (b) of this section and shall be supplied with hot and cold running water.

(e) Rooming house. — At least 1 water closet, lavatory basin and bathtub or shower properly connected to an approved water and sewer system and in good working condition shall be supplied for each 4 rooms within a rooming house, wherever said facilities are shared. Every lavatory basin and bathtub or shower shall be supplied with hot and cold water at all times.

(f) Hotels. — Where private water closets, lavatories, and baths are not provided, 1 water closet, 1 lavatory and 1 bathtub accessible from a public hallway shall be provided on each floor. Each lavatory, bathtub or shower shall be supplied with hot and cold water at all times.

(g) Toilet rooms and bathrooms
— Privacy. — Toilet rooms and bathrooms shall be designed and arranged to provide privacy.

(h) Toilet rooms and bathrooms — Direct access. — Toilet rooms and bathrooms shall not be used as a passageway to a hall or other space or to the exterior. At least 1 toilet room or bathroom in a dwelling unit shall be accessible from any sleeping room without passing through another sleeping room.

(i) Toilet rooms and bathrooms — Location on same story. — Toilet rooms and bathrooms serving hotel units, lodging units or dormitory units, unless located within such respective units, or directly connected thereto, shall be provided on the same story with such units and be accessible only from a common hall or passageway.

(j) Toilet rooms and bathrooms
— Floors. — Bathrooms and toilet rooms shall be provided with floors of moisture resistant material.

(k) Connections. — Water supply lines, plumbing fixtures, vents and drains shall be properly installed, connected and maintained in working order and shall be kept free from obstructions, leaks and defects and capable of performing the function for which they are designed.

(l) Maintained clean and sanitary. — All plumbing facilities shall be maintained in a clean and sanitary condition by the occupant so as not to breed insects and rats or produce dangerous or offensive gases or odors.

(m) Access for cleaning. — Plumbing fixtures shall be installed so as to permit easy access for cleaning both the fixtures and the areas about them.

(n) Water conservation. — Plumbing fixtures which are replaced shall be of water saving construction and use.

(o) Contamination. — The water supply shall be maintained free from contamination and all water inlets for plumbing fixtures shall be located above the overflow rim of the fixture.

(p) Supply. — The water supply systems shall be installed and maintained to provide at all times a supply of water to plumbing fixtures, devices and appurtenances in sufficient volume and at pressures adequate to enable them to function satisfactorily.

(q) Water heating facilities. — Water heating facilities shall be properly installed, properly maintained and properly connected with hot water lines to the fixtures required to be supplied with the hot water. Water heating facilities shall be capable of heating water to such a temperature so as to permit an adequate amount of water to be drawn at every required kitchen sink, lavatory basin, bathtub, shower and laundry facility or other similar units at a temperature of not less than 110° F.

(r) Connections. — Every sink, lavatory, bathtub or shower, drinking fountain, water closet or other facility shall be properly connected to either a public sewer system or to an approved private sewage disposal system.

(s) Maintenance. — Every plumbing stack, waste and sewer line shall be so installed and maintained as to function properly and shall be kept free from obstructions, leaks and defects to prevent structural deterioration or health hazards.

(t) Storm drainage. — An approved system of storm water disposal shall be provided and maintained for the safe and efficient drainage of roofs and paved areas, yards and courts and other open areas on the premises.