Triangle Engineering

1388 Haight Street #172

San Francisco, CA  94117

  1. (415)626-6972



I’m Duke Crestfield, P.E., and Triangle Engineering is my consulting engineering practice.

I specialize in existing buildings, including seismic upgrade, additions, alterations, and repairs.  Projects range from small projects at people’s homes to large multi-family and commercial buildings. 

I also provide Special Inspection services for jobs designed by other engineers.

My focus is on the practicality of the construction, in order to maximize value by giving the best building performance for the construction cost.


Inspections & Reports

Structural Design & Construction Documents

Special Inspection & Testing





Structural Engineers Association of Northern California (SEAONC)

Association of Bay Area Governments (ABAG) Earthquake & Hazards page

ABAG Planset ‘A’ (prescriptive home seismic strengthening)

ABAG Soft Story Wood Frame page

ABAG Retrofit Contractor List


About Triangle Engineering