[1] The district is known in Portland for a diagonal street pattern, which is at odds with the rectilinear grid of the surrounding area.

[5] The homes in the district, mostly developed between 1905 and 1930 (after Ladd's death), have been called a "architecturally rich mix of compatible early 20th century styles," notable for their "continuity of scale, setback, orientation, and materials.

"[1] Architectural styles represented include bungalow, craftsman, American Foursquare, Mission, Tudor, and Colonial Revival.

[5] Though the earliest deeds excluded Japanese and Chinese residents, except as servants, after those covenants expired, Ladd's Addition was one of the few areas by 1939 informally designated as open to 'oriental' families.

[6] Each of the four smaller, diamond-shaped "circles" to the east, west, north, and south contains one of Portland's rose test gardens.