Epic Church at 491 Post Street

A Multidisciplinary Condition Assessment Prepares a Historic Church for Its Next Chapter

Thornton Tomasetti is helping Epic Church evaluate its newly acquired home at 491 Post Street in San Francisco. After the congregation outgrew its previous space, the church acquired this 1913 building to serve its community. We supported the real-estate decision with high-level due diligence, including a probable maximum loss (PML) study; our structural evaluation and completed building envelope assessment are now informing potential improvements. 

Since its reconstruction after the 1906 earthquake, the building has served as a church and, for a short period, as a college lecture hall. Its structure combines concrete shear walls with an integrated steel moment frame—a hybrid that does not fit neatly into today’s standard building types. Our structural team evaluated how the components work together and conducted material sampling to better understand existing conditions. After Epic Church purchased the building, we were able to use more invasive testing than was possible during transaction-stage due diligence, giving the evaluation a firmer basis.

Assessing the Historic Church From Frame to Skylight

Our building-envelope team completed a condition assessment that found some water intrusion and damaged glazing at the atrium skylight, though overall, the envelope has performed reasonably well for its age. The skylight is currently boarded to protect against breakage; potential replacement with shatter-resistant glass could protect the feature while bringing daylight back into the atrium. Together with the ongoing structural investigation, this work gives Epic Church a clearer picture of the building’s condition as it considers next steps.

Planning for Future Improvements 

The findings from these assessments will inform the evaluation of seismic upgrade strategies. Potential future work may also include targeted reconfiguration of basement meeting, childcare, and activity spaces, as well as repairs to the atrium skylight glazing. As the project evolves, our engineers can draw on Thornton Tomasetti’s expertise across disciplines to help Epic Church address needs as they emerge and coordinate solutions for the building as a whole. Together, these efforts give Epic Church the information and multidisciplinary support to plan a long-term home for its congregation in a historic San Francisco building.