4 Story 3-Unit Residential in San Francisco

[dockofthebay]

Hey There,

I wanted to get people's thoughts on coming with up fees for structural engineering of a 4 story 3-unit residential building in San Francisco.

Footprint is pretty small, ~1,500 sq ft. It has some transfer conditions where shear walls are offset with a garage opening on one end so it will need a steel frame at that end in the foundation. It will be a "row house" as well, so it will be butted up against adjacent properties on both sides. Rooftop is an accessible deck with some coverage for PV panels. No Geotech report yet, so assuming typical spread footings.

I see posts here talking about $1-$2/sq ft or less than 1% of construction cost to determine structural fees. The sq ft method would yield something like $4k-$8k, and that is not close to the hours needed to complete the design. Any thoughts on what the range of structural fees $/sq ft for similar projects in San Francisco? Or a range of $/sq ft of construction cost and % of this for structural engineering fees? I recall it was around $500/sq ft to build residential in San Francisco, but I think this was pre-2020. Of course, making reasonable assumptions on finish costs etc.

Also something technical, any tips on how to handle the "row house" configuration? Concerns about adjacent foundations during excavation for footings, and of course, seismic considerations. San Francisco seems to understand the "row house" is a configuration that occurs, but any recommended approaches regarding any loads that may be imposed on the new structure by the adjacent existing?

Appreciate any help or tips you have. Thank you.

 

[alt0]

I think your fees should be substantially higher (like... 20-30k at least)
And as you identified, property line foundation design will be critical. If the adjacent buildings have inadequately buried footings (as is often the case) excavation needs to be done very carefully with recommendations from the soils engineer, may need to do chemical soil stabilization or segment the excavation process or even underpin the neighboring building.

 

[dockofthebay]

Thanks alt0 for your thoughts on it. At 20-30k, I'd say that's between 2.5 to 4 weeks of work. That's about $1.25 to $1.90 a square foot, and its a pretty small typical row house footprint in san francisco. I feels like it would take more than 3-4 weeks to fully calc out including drafting for plans and details.

The potential underpinning situation with the adjacent buildings pretty forward in my mind though. Asked for drawings at adjacent buildings (probably wont get them), not a fan of touching and taking liability on an adjacent building foundation not owned by the project.