In accordance with the Mandatory Seismic Retrofit Program (MSSP), San Francisco requires the retrofit of pre-1978 wood-frame soft-story buildings which have not been previously seismically strengthened. The goal of the program is to ensure the safety and continuance of San Francisco’s housing to create a more resilient city. Deprived of retrofitting, the weak buildings may be exposed to major structural damage and possible collapse.
How much will it cost?
The Community Action Plan for Seismic Safety (CAPSS) with the San Francisco Department of Building Inspection estimated soft story retrofit costs for at risk buildings. Construction costs were estimated for typical soft story wood frame buildings (excluding engineering).
- Moment Frame solution: $59,000 to $132,000
- Cantilevered columns: $58,000 to $114,000
A third option for a reduced retrofit was also considered at $49,000 to $79,000 was modeled but this would leave the building uninhabitable after a large quake and not recommended.
Costs generally fall into 3 groups:
- Engineering fees
- Construction costs
- Permitting Fees
These generally run from $6,000 to $10,000 per completed and approved set of plans. Depending on the level of experience of the engineer(s), companies will charge anywhere between $90 and $200 per hour. Some engineering companies may offer a single blended rate to cover all engineering (typically $110 or more).
San Francisco requires two signed, sets of plans prepared by a licensed architect, civil or structural engineer that includes structural calculations.
Some construction companies may offer “Design Build” for a retrofit project and offer low fixed pricing for engineering. The building owner should beware that most companies will aim to recover any discount on the engineering by an additional mark up on the construction – so building owners will end up paying the same when the project is complete.
It is common that some building testing will be required for the engineering. For example – an engineer will need to remove stucco to see the dimensions and quality of pre-existing wood beams and columns, or structural ironwork. This type of testing is termed “destructive” and will eventually need patching. Non-destructive testing with ground penetrating radar (GPR) can also be used and is frequently simpler, quicker and cheaper.
Cantilevered columns are expected to be a popular solution. New concrete footings are laid, often with a grade beam for support. The cantilevered columns are then fastened to existing structural members to transmit the load from the footings to the second floor. A report from Applied Technology Council (ATC) for the San Francisco Soft Story program found cantilevered columns to be an effective solution, but similar in cost and performance to moment frames. One potential advantage is that cantilevered columns may be more space efficient than a moment frame with a beam fixed at the top of the columns. A single bay cantilevered solution is expected to cost around $15,000 to $20,000 fully installed.
Moment frames can be delivered to the jobsite either as 2 columns and a connecting beam, or fully pre-assembled into a single unit. A full frame has 2 columns at the height of the soft story floor (roughly 8’) and the beam the width of the open bay (~8’ to 14’) – although there are many permutations. Moment frames can be bolted or welded in fabrication or at the jobsite. Some units are termed ‘Special’ moment frames – and these are distinguished by having a ductile plate or fuse at the connection between the beam and columns. This component is designed to deform under lateral loads from a seismic event and may save the columns and beams from permanent deformation. Costs vary on the exact size and complexity of installation – but roughly $20,000 to $25,000 per installed frame can be expected.
A rough rule is that a moment frame is required for every 2 parking bays. However – this can vary depending on the strength of existing shear walls and pre-existing steel structural supports.
It is also expected that a few buildings may have already been retrofitted to a sufficient level – and in these cases an engineer is required to submit drawings and calculations and certify that the building is compliant. While the building owner will not have to pay for any more construction – the engineering required is almost the same as if the building had not been already been retrofitted – so the fees could be in the $5,000 to $10,000 range.
The cost of a building permit application is calculated as a percentage of the construction costs San Francisco Building Code Section 110A.
San Francisco Department of Building Inspection Public Retrofit Cost Data
To view the San Francisco Soft Story Seismic Ordinance or to review additional details please visit http://sfdbi.org/softstory
|Haight Street||4 units/3 stories||$120,000.00|
|Mission Street||4 units/3 stories||$50,000.00|
|Stockton Street||4 units/3 stories||$40,000.00|
|Dolores Street||5 units/3 stories||$90,000.00|
|Haight Street||5 units/3 stories||$24,500.00|
|Alemany Blvd||6 units/2 stories||$56,000.00|
|Baker Street||6 units/3 stories||$68,000.00|
|Broderick Street||6 units/3 stories||$70,470.00|
|Bryant Street||6 units/3 stories||$51,000.00|
|Clementina Street||6 units/3 stories||$38,000.00|
|Clinton Park||6 units/3 stories||$45,000.00|
|Dolores Street||6 units/3 stories||$57,000.00|
|Dore Street||6 units/3 stories||$85,000.00|
|Freelon Street||6 units/3 stories||$35,000.00|
|Greenwich Street||6 units/3 stories||$69,000.00|
|Guerrero Street||6 units/3 stories||$86,000.00|
|Hoff Street||6 units/3 stories||$60,000.00|
|Langton Street||6 units/3 stories||$50,000.00|
|Lexington Street||6 units/3 stories||$38,000.00|
|Lexington Street||6 units/3 stories||$120,000.00|
|Octavia Street||6 units/3 stories||$100,000.00|
|Pearl Street||6 units/3 stories||$54,000.00|
|Russ Street||6 units/3 stories||$5,000.00|
|Shotwell Street||6 units/3 stories||$24,000.00|
|Stockton Street||6 units/3 stories||$48,000.00|
|17th Street||7 units/3 Stories||$106,600.00|
|Douglass Street||7 units/3 stories||$69,000.00|
|Pine Street||7 units/3 stories||$125,500.00|
|Powell Street||7 units/3 stories||$57,000.00|
|14th Street||7 units/4 stories||$39,600.00|
|Jackson||7 units/4 stories||$105,800.00|
|Clement Street||8 units/3 stories||$50,000.00|
|Dehon Street||8 units/3 stories||$67,000.00|
|Guerrero Street||8 units/3 stories||$25,000.00|
|Guerrero Street||8 units/3 stories||$100,000.00|
|Haight Street||8 units/3 stories||$40,000.00|
|Stockton Street||8 units/3 stories||$80,000.00|
|Dolores Street||9 units/2 stories||$70,000.00|
|Francisco Street||9 units/3 stories||$70,000.00|
|Guerrero Street||9 units/3 stories||$40,000.00|
|Haight Street||9 units/3 stories||$100,000.00|
|Lombard Street||9 units/3 stories||$100,000.00|
|Market Street||9 units/3 stories||$130,000.00|
|Divisadero Street||10 units/2 stories||$55,000.00|
|10th Avenue||10 units/3 stories||$60,000.00|
|16th Street||10 units/3 stories||$71,000.00|
|34th Avenue||10 units/3 stories||$94,300.00|
|3rd Avenue||10 units/3 stories||$83,000.00|
|Gough Street||10 units/3 stories||$180,000.00|
|17th Street||11 units/3 stories||$92,000.00|
|Divisadero Street||11 units/3 stories||$126,000.00|
|Mission Street||11 units/3 stories||$100,000.00|
|Union Street||11 units/3 stories||$83,580.00|
|Valencia Street||11 units/3 stories||$4,000.00|
|Valencia Street||12 units/2 stories||$12,000.00|
|24th Street||12 units/3 stories||$120,000.00|
|Fillmore Street||12 units/3 stories||$34,200.00|
|Fillmore Street||12 units/3 stories||$52,135.00|
|Folsom Street||12 units/3 stories||$67,000.00|
|Gough Street||12 units/3 stories||$80,000.00|
|Haight Street||12 units/3 stories||$100,000.00|
|Hoff Street||12 units/3 stories||$120,000.00|
|Jackson||12 units/3 stories||$45,000.00|
|Pacific Avenue||12 units/3 stories||$54,000.00|
|Polk Street||12 units/3 stories||$106,000.00|
|Valencia Street||12 units/3 stories||$50,000.00|
|6th Street||13 units/3 stories||$40,000.00|
|8th Street||13 units/3 stories||$30,000.00|
|Lombard Street||13 units/3 stories||$81,000.00|
|Market Street||13 units/3 stories||$60,000.00|
|Valencia Street||14 units/3 stories||$65,000.00|
|48th Avenue||15 units/3 stories||$135,000.00|
|Cervantes Blvd||15 units/3 stories||$105,000.00|
|Valencia Street||15 units/3 stories||$70,000.00|
|Hyde Street||15 units/4 stories||$85,000.00|
|15th Avenue||16 units/3 stories||$75,000.00|
|Capp Street||16 units/3 stories||$43,000.00|
|Divisadero Street||16 units/3 stories||$50,000.00|
|Pine Street||17 units/2 stories||$50,000.00|
|Beach Street||18 units/3 stories||$225,000.00|
|Broderick Street||18 units/3 stories||$90,000.00|
|Broderick Street||18 units/3 stories||$95,000.00|
|Francisco Street||18 units/3 stories||$28,000.00|
|Francisco Street||18 units/3 stories||$79,500.00|
|Mission Street||18 units/3 stories||$52,000.00|
|Chestnut Street||21 units/3 stories||$155,000.00|
|Albion Street||22units/3 stories||$50,000.00|
|Van Ness Avenue||23 units/3 stories||$81,000.00|
|20th Street||24 units/3 stories||$100,000.00|
|Chestnut Street||24 units/3 stories||$70,000.00|
|Valencia Street||24 units/3 stories||$137,000.00|
|Union Street||30 units/3 stories||$80,000.00|
|2nd Street (101 Clement)||$22,000.00|
|Mission Street (Hotel)||$64,000.00|
How Long Do I Have to Comply?
|Compliance Tier||Submittal of Permit Application with Plans for Seismic Retrofit Work||Completion of Work and Issuance of Certificate of Final Completion|
|1||September 15, 2017|
|2||September 15, 2018|
|3||September 15, 2017||September 15, 2019|
|4||September 15, 2018||September 15, 2020|
Does My Building Require Retrofitting?
View the SFDBI’s Soft Story Properties List to see if your building requires retrofitting.
The important place to start is to get an assessment. It is possible that your building doesn’t need retrofitting or that there is a solution for your building can be very simple. Retrofitting costs and solutions vary, but you can rest assured knowing that Penhall offers a value engineering approach that is both economical and compliant with the local ordinance.
Before you start the complicated process of your soft-story retrofitting alone please take a moment to call Penhall Seismic Retrofit Services for your free evaluation at 415-619-3204.