Building Height Measurement and Calculation in the Dallas Development Code

Under the City of Dallas Development Code, building height is measured from the average grade of the building's corners to either the highest point of the structure or the midpoint of the roof, depending on the specific roof design. In many zoning districts, the final allowable height is determined by the "Residential Proximity Slope," a calculated plane that limits the vertical rise of a building based on its horizontal distance from nearby residential neighborhoods [Section 51A-4.412].

General Measurement and Calculation Rules

The City of Dallas Development Code establishes a standardized method for determining the base point (grade) and the termination point for vertical measurement. According to the City of Dallas rules, "Grade" is defined as the average of the finished ground surface elevations measured at the highest and lowest exterior corners of a structure [Section 51A-2.102].

The termination point of the height measurement varies based on the architectural style of the roof:

Roof Type	Point of Measurement (Termination)
Gable, Hip, or Gambrel Roof	The midpoint of the vertical dimension between the lowest eaves and the highest ridge.
Dome Roof	The midpoint of the vertical dimension of the dome.
All Other Structures (Flat, etc.)	The highest point of the structure.

Special Height Projections and Exceptions

The City of Dallas allows certain functional and decorative elements to exceed the maximum height limits established for a specific zoning district. In any City of Dallas district where the height is limited to 36 feet or less, the following structures may project up to 12 feet above the maximum height limit [Section 51A-4.408]:

• Elevator penthouses or bulkheads.
• Mechanical equipment rooms, cooling towers, and tanks.
• Ornamental cupolas, domes, skylights, and clerestories.
• Visual screens surrounding roof-mounted mechanical equipment.
• Chimneys, vent stacks, and amateur communications towers.
• Parapet walls (limited to a height of four feet).

In residential districts (Single Family, Duplex, Townhouse, and certain Multifamily), specific restrictions apply: no dormer eaves may project above the maximum structure height, although the highest point of a gable, hip, or dome roof may project up to 12 feet above the limit [Section 51A-4.408].

Residential Proximity Slope (RPS) Calculation

The most complex element of height calculation in the City of Dallas is the Residential Proximity Slope. This is an imaginary plane projected upward and outward from a "site of origination" (typically a low-density residential property line). No structure within the restricted area may penetrate this slope [Section 51A-4.412].

Zoning Category of Site of Origination	Angle of Projection	Extent of Restriction
R, R(A), D, D(A), TH, and TH(A) Districts	18.4° (1 to 3 slope)	Infinite
CH, MF-1, MF-1(A), MF-2, and MF-2(A) Districts	45° (1 to 1 slope)	Terminates at 50 feet from the site of origination

Height Standards in Walkable Urban (Form) Districts

For City of Dallas properties located within Walkable Urban (Form) Districts (Article XIII), height is measured both in feet and in stories. In these districts, the City of Dallas counts an attic story as a half-story, while a basement is not considered a story. If a ground story is more than five feet above the finished grade, it counts as an additional story [Section 51A-13.302].

The City of Dallas maximum height limits for these districts are categorized by intensity:

District Intensity	Max Height in Stories	Max Height in Feet
Low (e.g., WMU-3, WR-3)	3½ Stories	50 Feet
Low (e.g., WMU-5, WR-5)	5 Stories	80 Feet
Medium (e.g., WMU-8, WR-8)	8 Stories	125 Feet
Medium (e.g., WMU-12, WR-12)	12 Stories	180 Feet
High (e.g., WMU-20, WR-20)	20 Stories	300 Feet
High (e.g., WMU-40, WR-40)	40 Stories	600 Feet

Sections Cited

• Sec. 51A-2.102. Definitions.
• Sec. 51A-4.408. Maximum Building Height.
• Sec. 51A-4.412. Residential Proximity Slope.
• Sec. 51A-13.302. Height.