E.C. Landberg was educated in Dayton, Oh.; University of Cincinnati, 1913; and received private instruction in advanced structural engineering 1918-1923. Traveled in France and England, studying architectural types and construction. Worked in Charleston, W.Va., with J.L. Montgomery and State Architect J. Russ Warne 1914-1917; with the Ferro Concrete Construction Co. in Cincinnati 1917-1923; and then on his own and with his brother G.T. Landberg after 1931. Listed in Cincinnati 1928-1962, although much of his practice was in N. Ky., including public schools (he is said to have been one of the first Roman Catholics to break this tacit barrier), such as the Dayton (Ky.) High School (recently converted into apartments), and the Lincoln Grant School on Greenup St., Covington, an attractive Moderne facility for Black children (1931). The firm also designed the Mariemont Jr.-Sr. High School (1936-1939), and the N. Avondale School. The grand, belated Moderne Scottish Rite Masonic Temple on Madison Avenue in Covington (1955) is attributed to E.C. Landberg. He was associated with G. Truman Landberg (ca. 1898-1951) on these and other projects.

E.C. Landberg's early work was published on the brink of the Depression in A Monograph of the Work of E.C. Landberg, Architect (Cincinnati: Universal Press Publishing, 1929). This displays a varied body of work, including many residences and apartment houses in a range of scales and styles (although mostly vaguely Tudor Revival), schools (with some Arts & Crafts aspects), lodge halls, churches (Collegiate Gothic), and a few commercial-cum-residential buildings (Dayton and Bellevue, Ky.), and finally the Silvia Theatre in Bellevue. Almost all the work is in Northern Kentucky; the residences in Fort Thomas, and the other buildings in the river towns or inland. The advertisements at the back of the brochure (like that on H.W. Cordes & Sons) include much other interesting information on builders and suppliers, often illustrated, and possible lists of other attributions to Landberg.