Hyperbolic paraboloid thin shell roof construction has now scored a number of significant successes in the United States and the use of this dramatic design concept is no longer automatically newsworthy. But its use in a recent West Coast construction project has imparted some new dimensions, both esthetic and economic, which are worthy of comment. The project in question is an 800 seat church in St. Charles Catholic Parish, Spokane, Washington. The architects designed a plan which would provide the greatest seating capacity for the area of the proposed building and give maximum proximity to the altar. A fan-shaped design showed the greatest promise. While a full h/p roof was not right for this shape, a modification of a parallelogram offered the perfect answer to the problem. Fortunately a member of the firm of architects was also a structural engineer who could work out the details of prestressing in a new departure from the basic h/p. Using the h/p eliminated the need for any supporting pillars, thus allowing for greater seating capacity. Another Seattle church of ordinary rectangular shape, built in 1948 at a cost of $400,000, seats only 600. Against a probable 1959 replacement cost of $480,000 for this structure, the St. Charles church was built for $350,000 and seats 800. One economy of the h/p construction was that the shell form reduces the area of the perimeter walls.