D.C. Municipal Regulations (Last Updated: September 13, 2017) |
Title 11. ZONING REGULATIONS OF 2016 |
SubTilte 11-C. GENERAL RULES |
Chapter 11-C14. RETAINING WALLS |
Section 11-C1401. GENERAL PROVISIONS
-
1401.1 The height of a retaining wall shall be determined as follows:
(a) The height of a retaining wall is the vertical distance measured from the natural grade at the base of the wall to the top of the wall;
(b) When the height of a retaining wall varies, the height shall be measured at the highest point of the wall, from the natural grade at the base of the wall at that point; and
(c) Berms or other similar forms of intermittent terrain elevation shall not be included in measuring retaining wall height.
1401.2 Subject to the height limitations of Subtitle C § 1401.3 through 1401.6, the maximum height of a retaining wall shall be six feet (6 ft.).
1401.3 A retaining wall shall not exceed four feet (4 ft.) in height in the following locations, unless a lower height is required by Subtitle C § 1401.5 and 1401.6:
(a) Along a street frontage or property line;
(b) Within any required side setback;
(c) In the R-1-A, R-1-B, R-6, R-7, R-8, R-9, R-11, R-12, R-14, R-15, R-16, R-19, and R-21 zones, within twenty-five feet (25 ft.) of the rear property line, as measured from the rear property line inward; and
(d) In the R-2, R-3, R-10, R-13, R-17, R-20, and RF zones, within twenty feet (20 ft.) of the rear property line, as measured from the rear property line inward.
1401.4 A retaining wall located along a street frontage on a block with adjacent existing retaining walls shall not be greater in height than the tallest adjacent existing retaining walls up to the maximum height of four feet (4 ft.).
1401.5 A retaining wall located on any area between a property line and a building line shall not exceed a maximum height of forty-two inches (42 in.).
1401.6 A retaining wall abutting an improved alley in the R-3 or RF zones shall not exceed a maximum height of twelve feet (12 ft.).
1401.7 Retaining walls may be tiered or terraced provided that the width of the area between each retaining wall is at least twice the height of the lower retaining wall. The area between each wall shall be pervious and may not be paved or otherwise covered with impervious materials.