Foundations and structural members shall provide a safe, firm, and substantial base and support for the structure at all points.
Exterior walls shall be structurally sound and free of cracks and holes through which rodents or the elements can enter the buildings.
Masonry walls shall be kept pointed.
All exterior surfacing materials shall be kept securely fastened in place.
All exterior wood surfaces shall be kept painted, varnished, shellacked, or covered with other preservative, unless the wood is customarily used in its natural state.
D.C. Mun. Regs. tit. 14, r. 14-704