The exterior of a structure shall be maintained in good repair, structurally sound and sanitary so as not to pose a threat to the health, safety or welfare of the occupants and so as to protect the occupants from the adverse effects of the environment.
Each structure to which a street number has been assigned shall have the number so assigned displayed in a position easily observed and readable from the public right-of-way.
All supporting structural members of all structures shall be kept structurally sound, free of deterioration and maintained capable of safely bearing the dead and live loads imposed upon them.
Every foundation, exterior wall and roof and all other exterior surfaces shall be maintained in a workmanlike state of maintenance and repair and shall be kept in such condition as to exclude rats.
All foundation walls shall be maintained so as to carry the safe design and operating dead and live loads and shall be maintained plumb and free from open cracks and breaks, so as not to be detrimental to public safety and welfare.
Every exterior wall shall be free of holes, breaks, loose or rotting boards or timbers and any other conditions which might admit rain or dampness to the interior portions of the walls or to the occupied spaces of the building. All exterior surface materials, including wood, composition or metal siding, shall be maintained weatherproof and shall be properly surface-coated when required to prevent deterioration.
The roof shall be structurally sound, tight and not have defects which might admit rain. Roof drainage shall be adequate to prevent rainwater from causing dampness or deterioration in the walls or interior portion of the building. Roof water shall not be discharged in a manner that creates a nuisance to owners or occupants of adjacent premises or that creates a public nuisance.
All cornices, entablatures, belt courses, corbels, terra cotta trim, wall facings and similar decorative features shall be maintained in good repair with proper anchorage and in a safe condition.
All canopies, marquees, signs, metal awnings, stairways, fire escapes, standpipes, exhaust ducts and similar overhang extensions shall be maintained in good repair and be properly anchored so as to be kept in a safe and sound condition. They shall be protected from the elements and against decay and rust by the periodic application of a weather-coating material such as paint or other protective treatment.
All chimneys, cooling towers, smoke stacks and similar appurtenances shall be maintained structurally safe, sound and in good repair. All exposed surfaces of metal or wood shall be protected from the elements and against decay or rust by periodic application of weather-coating materials such as paint or similar surface treatment.
A. 
Every stair, porch, fire escape or balcony and all appurtenances attached thereto shall be so constructed as to be safe to use and capable of supporting the anticipated loads and shall be maintained in sound condition and good repair. Every stair, porch and fire escape shall be maintained free of hazardous conditions such as snow, ice, mud and other debris.
B. 
Every flight of stairs which is more than four risers high shall have a handrail on at least one side of the stair, and every open portion of a stair fire escape, porch, landing or balcony which is more than 30 inches (762 millimeters) above the grade below shall have guardrails. Handrails shall be not less than 30 inches (762 millimeters) nor more than 34 inches (864 millimeters) high, measured vertically above the nosing of the treads. Guardrails shall be not less than 30 inches (762 millimeters) high above the floor of the porch, landing or balcony. Every handrail and guardrail shall be firmly fastened and capable of bearing normally imposed loads and shall be maintained in good condition.
Every window, door and frame shall be constructed and maintained in such relation to the adjacent wall construction so as to exclude rain as completely as possible and to substantially exclude wind from entering the dwelling or structure.
Every window and exterior door shall be fitted reasonably in its frame and be weathertight. Weather stripping shall be used to exclude wind or rain from entering the dwelling or structure and shall be kept in sound condition and good repair.
Every required window sash shall be fully supplied with approved glazing materials which are without open cracks and holes.
Every window, other than a fixed window, shall be capable of being easily opened and shall be held in position by window hardware.
A. 
During the period from April 1 to December 1, every door and window or other outside opening used for ventilation purposes serving any building containing habitable rooms, food preparation areas, food service areas or any areas where products used in food for human consumption are processed, manufactured, packaged or stored shall be supplied with approved tight-fitting screens of not less than 16 mesh per inch, and every swinging screen door shall have a self-closing device in good working condition.
B. 
Exception. Screen doors shall not be required for out-swinging doors or other types of openings which make screening impractical, provided that other approved means such as air curtains or insect repellent fans are employed.
Every exterior door and its hardware shall be maintained in good condition. Door locks on all doors entering dwelling units shall be in good repair and capable of tightly securing the door.
Every basement hatchway shall be so constructed and maintained as to prevent the entrance of rats, rain and surface drainage water into the structures.
Every basement window which is openable shall be supplied with rat-proof shields or storm windows or other material affording protection against the entry of rats.