Viewshed Analysis Methodology

The Viewshed is a defined visual field, not a general view. It is a seven-degree angle within the Inner Corridor, determined by the line of sight from a point four feet above the edge of Mulholland Drive’s paved roadway. Projects on Inner Corridor lots that are visible from Mulholland Drive may not penetrate the Viewshed without prior Director approval.

The Viewshed Analysis is the deliverable that demonstrates non-penetration. It is required only for Inner Corridor projects that are Visible. It is distinct from the Visibility Study, which determines whether the project is Visible in the first place.

The two deliverables are separate and frequently confused.

The Visibility Study consists of a minimum of seven lines of sight from Mulholland Drive toward the project within the project’s three-quarter-mile Visibility Arc. It cannot be limited to a perpendicular angle of view. Each photograph is annotated Visible or Not Visible, with the obstructing feature labeled if applicable.

The Viewshed Analysis determines, for Visible Inner Corridor projects, the maximum building height that does not penetrate the Viewshed. The analysis ignores proposed landscaping that screens the project. Plant material is not a Viewshed remedy.

• Downslope lots: the analysis is conducted from the side of Mulholland Drive nearest the project, beginning at a point four feet above the edge of the paved roadway. Curbs, berms, and similar structures are not part of the roadway.
• Upslope lots: the analysis is conducted from the side of Mulholland Drive farthest from the project, beginning four feet above the paved-roadway edge.

• The Viewshed Analysis run from the correct point of origin given the lot’s upslope/downslope status.
• The four-foot origin point measured from the paved-roadway edge — not from a curb, berm, or shoulder.
• Demonstration that no portion of the building or structure penetrates the Viewshed at any point along the building envelope.
• The analysis ignores proposed landscaping that screens the project.
• Site sections (Exhibit E-9) extended to Mulholland Drive that align with the Viewshed Analysis findings.

• Distinguish the Visibility Study from the Viewshed Analysis from the outset. The first establishes whether the project is Visible; the second establishes whether a Visible Inner Corridor project penetrates the Viewshed.
• Run the Viewshed Analysis as part of schematic design, not as a final-deliverable check. The Viewshed often constrains roof geometry and parapet height.
• Where the analysis shows penetration, evaluate whether the project can be redesigned to fit beneath the Viewshed before pursuing Director approval, which requires findings the project complements the view from Mulholland Drive.

Source: Mulholland Scenic Parkway Specific Plan, §4 (Viewshed and Visibility Arc definitions) and §5 D 1 (Viewshed Protection). Height-measurement methodology referenced at LAMC §12.03. Visibility Study requirements per the Project Compliance filing instructions.