CHAPTER
32
ENCROACHMENTS IN THE PUBLIC RIGHT-OF-WAY
By using the language “encroachments into the public right-of-way,” the code is referring to the projections of appendages and other elements from the building that are permitted to project beyond the lot line of the building site and into the public right-of-way. The intent of the code is that projections from a building into the public right-of-way shall not interfere with its free use by vehicular and pedestrian traffic, and shall not interfere with public services such as fire protection and utilities.
Section 3201 General
The International Building Code® (IBC®) requires that any construction that projects into or across the public right-of-way be constructed as required by the code for buildings on private property. Furthermore, the intent is that the provisions of this chapter are not considered so as to permit a violation of other laws or ordinances regulating the use and occupancy of public property. Many jurisdictions have ordinances regulating the use and occupancy of public property that go beyond the provisions of this chapter, many of which may be more restrictive and not permit the projections permitted by the IBC. Where there are no other ordinances that prohibit such construction, it is the intent of this chapter to permit the construction of the connecting structure between buildings either over or under the public way.
These types of permanent uses of the public way are often permitted by the jurisdiction under a special license issued by the public works agency. Where these uses create no obstruction to the normal use of the public way, the jurisdiction, by authorizing connecting structures between buildings on either side of the public way, can derive revenue from a licensing agreement, which can be of assistance in maintaining the public right-of-way.
The code prohibits roof drainage water from a building to flow over a public walking surface, as well as any water collected from an awning, canopy, or marquee, and condensate from mechanical equipment. The intent is not necessarily to prevent drainage water from flowing over public property in general, but rather to prevent drainage water from flowing over a sidewalk or pedestrian walkway that is between the building and the public street or thoroughfare.
There are at least two problems that arise when drainage water from a building or structure is allowed to flow over a public sidewalk:
1. Under proper conditions of light and temperature, algae will form where the water flows across the sidewalk and create a hazardous, slippery walking surface.
2. During heavy rain storms, the velocity and force of the water emitting from the drain can create hazardous walking conditions for pedestrians.
Therefore, the usual procedure is to carry the drain lines from the roof or other building elements inside the building through the wall of the building and under the sidewalk through a curb opening into the gutter.
Section 3202 Encroachments
The projection of any structure or appendage is generally regulated in regard to its relationship to grade. Those encroachments found below grade, such as structural supports, vaults, and areaways, are governed in one fashion. Those encroachments located above grade, but below 8 feet (2,438 mm) in height, are more severely controlled because of their immediate location adjacent to public areas. Although projections that are located 8 feet (2,438 mm) or more above grade tend to have fewer implications, such encroachments are also regulated.
3202.1 Encroachments below grade. Footings, foundations, piles, and similar structural elements that support the building and are erected below grade are not permitted to project beyond the lot lines. There is an allowance for footings that support exterior walls, provided the projection does not extend more than 12 inches (305 mm) beyond the street lot line, and that the footings or supports are located at least 8 feet (2,438 mm) below grade. In this exception, the code assumes that there will be no utilities or other public facilities below this depth adjacent to the building and, therefore, permits footings to project a limited amount where they are below the 8 feet (2,438 mm) depth. It should be noted that this encroachment is permitted for street walls only and does not apply to interior lot lines. See Figure 3202-1.
Figure 3202-1 Encroachments below grade.
Where vaults, basements, and other enclosed spaces are located below grade in the public right-of-way, they shall be further regulated by the ordinances and conditions of the applicable governing authority. In many cases, the space below the sidewalk or other area adjacent to the building in the public right-of-way is not used for public purposes such as utilities, sewers, and storm drains (except for catch basins); therefore, where local ordinances do not prohibit the use of space beneath the sidewalk or other public area, the code permits its use by adjoining property owners. Usually the basement or other enclosed space of an adjoining building is extended beneath the public right-of-way and is used for any of the uses permitted by the code. This is a revocable permission, as the jurisdiction may find at a later date that there is a public need for the public use of the space beneath grade.
3202.2 Encroachments above grade and below 8 feet in height. Building components that may arbitrarily project into the public right-of-way pose a considerable hazard to pedestrians or other users of the right-of-way. Therefore, doors and windows are prohibited from opening into such an area. However, certain features of the building that are permanent in nature are permitted to encroach into the public right-of-way to a limited degree. Where steps are permitted by other provisions of the IBC, they may project into the right-of-way up to 12 inches (305 mm), provided they are protected by guards at least 3 feet (914 mm) high or similar protective elements such as columns or pilasters. The intent of the provision is that the encroachment be small enough so as not to obstruct pedestrian or vehicular traffic and yet provide some protection for occupants of the building to look each way before proceeding into the right-of-way.
Encroachments into the public right-of-way for certain architectural features are also permitted, but again, only a limited projection is allowed. For columns or pilasters, the maximum projection is 12 inches (305 mm). Other architectural features such as lintels, sills, and pediments are limited to a 4-inch (102-mm) projection. Awnings, including valances, may only extend into the public right-of-way when the vertical clearance from the right-of-way to the lowest part of the awning is at least 7 feet (2,134 mm).
3202.3 Encroachments 8 feet or more above grade. The code permits the projection of awnings, canopies, marquees, signs, balconies, and similar architectural features at a height of 8 feet (2,438 mm) or more in accordance with Figures 3202-2 and 3202-3. The intent of the code is that no projection should be permitted near the level of the public right-of-way and up to 8 feet (2,438 mm) in height so that the free passage of pedestrians along the sidewalk or other walking surface will not be inhibited. At the 8 feet (2,438 mm) height and above, projections are permitted as long as they do not interfere with public utilities. It is generally assumed that utility lines for telephones or power will not occupy this zone except for the service entrances to the buildings. There are jurisdictions that have high-voltage power lines running along the sidewalk, and the regulations of the agency that regulates the power companies generally require certain clearances from these lines. Therefore, in addition to the requirements shown in Figures 3202-2 and 3202-3, power-line clearances should also be checked, and the requirements of the National Electrical Code® should be reviewed when it is adopted by the jurisdiction. Where such awnings, canopies, balconies, and similar building elements are located 15 feet (4,572 mm) or more above grade, their encroachment is unlimited.
Figure 3202-2 Awning, canopy, marquee, and sign projections.
Figure 3202-3 Balcony and appendages projections.
It is not uncommon to find a pedestrian walkway or a similar circulation element to be constructed over a public right-of-way. Such a condition is permitted subject to the approval of the local authority having jurisdiction. In no case, however, should the vertical clearance between the right-of-way and the lowest part of the walkway be less than 15 feet (4,572 mm). A clearance of at least 15 feet (4,572 mm) allows not only for unobstructed pedestrian travel but for vehicular access as well.