Mid-century modern architect, Richard Neutra, designed the Arboretum, a 22,288-square-foot structure built in 1962, to serve as the original sanctuary for Rev. Robert Schuller’s congregation. Rev. Schuller would speak to up to 1,400 churchgoers inside the Arboretum, and walk outside on the balcony to address additional congregants parked in their cars, just as he did at a drive-in movie theatre where he first preached.

In 2012, an extensive renovation of the Arboretum began. Updates included the creation of an innovative and energy-efficient underground air conditioning system, seismic strengthening, glass replacement, landscaping and other aesthetic enhancements. Since all elements of the Arboretum were specifically designed by the Neutra, the diocese studied archival records to ensure every dimension and pane of glass matched original specifications. Completed in just six months, the Arboretum’s renovation has won several awards.