On All Saints Day in October of 2000, the design team was selected to begin the architectural design for the new co-cathedral that would become the ecclesiastic center of the Diocese. Working with Archbishop Jospeh Fiorenza, then Bishop of Galveston-Houston, a model was constructed and taken to the Vatican where he obtained approval by then-Pope John Paul II.
There was a shared belief that the architecture should reflect the values of Houston, a modern, vibrant, 21st-century city. The exterior is a contrast of large volumes built with over 73,000-square-feet of limestone. The copper dome crowning the Cathedral supports a 17-foot-high, gold leaf cross, one of three adorning the Cathedral and bell tower. The Resurrection window adorning the front facade depicts Christ rising over Houston as the Victor over sin and death. The interior grand dome rises 125-feet above the altar and is encircled by twelve windows of stained glass bearing the twelve apostles. Clerestory windows encircle the perimeter washing the space with clear and colored light. At the center of the interior dome is an eight-foot oculus of the Holy Spirit in stained glass. A twelve-foot crucifix presides over the sanctuary. Two major shrines devoted to the Sacred Heart of Jesus and the Immaculate Conception grace the transepts.