In order to accommodate the growth of the Seattle congregation in the early 20th century, the Diocese of Olympia made plans for a new cathedral. In 1923, land was purchased on 10th East. The original plans and church model depicted the parishoners' grand concept of an ornate Gothic-style building with a 250-foot tall tower, requiring a decade of construction and over one million dollars. When the depression began in October 1929, financial problems meant that the building plans had to be modified. In the end, San Francisco architects Arthur Brown Jr. and E. Frere Champney designed a simple cube shape which was given the nickname “The Holy Box.”

The Henry & McFee Contracting Company began construction in 1928. In order to build on Seattle’s steep ridges, the structure was stabilized on a sturdy concrete foundation, and the construction then continued in concrete. A ten-foot thick central slab of concrete with supporting pillars of steel and concrete at each corner was surrounded by four-foot thick slabs upon which walls and false buttresses were built with huge windows of frosted glass facing the north and south.