(a)   Adjoining walls. The owner of a new or altered structure shall preserve all adjoining independent and party walls from damage as provided in this section. The owner shall underpin where necessary and support the adjoining building or structure by proper foundations.
   (b)   Maintenance. In case an existing party wall is intended to be used by the person who causes an excavation to be made, and such party wall is in good condition and sufficient for the use of both the existing and proposed building, such person shall preserve the party wall from injury and support it by proper foundations at his or her own expense, so that it shall be and shall remain as safe and useful as it was before the excavation was commenced. During the demolition, the party wall shall be maintained weatherproof and structurally safe by adequate bracing until such time as the permanent structural supports have been provided.
   (c)   Beam holes. When a structure involving a party wall is being demolished, the owner of the demolished structure shall, at his or her own expense, bend over all wall anchors at the beam ends of the standing wall and shall brick up open beam holes and otherwise maintain the safety and usefulness of the wall.
   (d)   Party wall exitways. No party wall balcony or horizontal fire exit shall be destroyed unless and until a substitute means of egress has been provided and approved by the Superintendent of Inspection.
   (e)   Adjoining roofs. When a new building or demolition of an existing building is being prosecuted at a greater height, the roof, roof outlets and roof structures of adjoining buildings shall be protected against damage with adequate safeguards by the person doing the work.
(Ord. 3229, passed 10-24-1956)