San Francisco Soft Story Retrofit

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?

San Francisco Seismic RetrofitThe 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

Engineering 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.

Construction Costs

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.

Permitting Fees

The cost of a building permit application is calculated as a percentage of the construction costs San Francisco Building Code Section 110A.

Cost Data

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

LocationUnits/StoriesCost
Haight Street4 units/3 stories$120,000.00
Mission Street4 units/3 stories$50,000.00
Stockton Street4 units/3 stories$40,000.00
Dolores Street5 units/3 stories$90,000.00
Haight Street5 units/3 stories$24,500.00
Alemany Blvd6 units/2 stories$56,000.00
Baker Street6 units/3 stories$68,000.00
Broderick Street6 units/3 stories$70,470.00
Bryant Street6 units/3 stories$51,000.00
Clementina Street6 units/3 stories$38,000.00
Clinton Park6 units/3 stories$45,000.00
Dolores Street6 units/3 stories$57,000.00
Dore Street6 units/3 stories$85,000.00
Freelon Street6 units/3 stories$35,000.00
Greenwich Street6 units/3 stories$69,000.00
Guerrero Street6 units/3 stories$86,000.00
Hoff Street6 units/3 stories$60,000.00
Langton Street6 units/3 stories$50,000.00
Lexington Street6 units/3 stories$38,000.00
Lexington Street6 units/3 stories$120,000.00
Octavia Street6 units/3 stories$100,000.00
Pearl Street6 units/3 stories$54,000.00
Russ Street6 units/3 stories$5,000.00
Shotwell Street6 units/3 stories$24,000.00
Stockton Street6 units/3 stories$48,000.00
17th Street7 units/3 Stories$106,600.00
Douglass Street7 units/3 stories$69,000.00
Pine Street7 units/3 stories$125,500.00
Powell Street7 units/3 stories$57,000.00
14th Street7 units/4 stories$39,600.00
Jackson7 units/4 stories$105,800.00
Clement Street8 units/3 stories$50,000.00
Dehon Street8 units/3 stories$67,000.00
Guerrero Street8 units/3 stories$25,000.00
Guerrero Street8 units/3 stories$100,000.00
Haight Street8 units/3 stories$40,000.00
Stockton Street8 units/3 stories$80,000.00
Dolores Street9 units/2 stories$70,000.00
Francisco Street9 units/3 stories$70,000.00
Guerrero Street9 units/3 stories$40,000.00
Haight Street9 units/3 stories$100,000.00
Lombard Street9 units/3 stories$100,000.00
Market Street9 units/3 stories$130,000.00
Divisadero Street10 units/2 stories$55,000.00
10th Avenue10 units/3 stories$60,000.00
16th Street10 units/3 stories$71,000.00
34th Avenue10 units/3 stories$94,300.00
3rd Avenue10 units/3 stories$83,000.00
Gough Street10 units/3 stories$180,000.00
17th Street11 units/3 stories$92,000.00
Divisadero Street11 units/3 stories$126,000.00
Mission Street11 units/3 stories$100,000.00
Union Street11 units/3 stories$83,580.00
Valencia Street11 units/3 stories$4,000.00
Valencia Street12 units/2 stories$12,000.00
24th Street12 units/3 stories$120,000.00
Fillmore Street12 units/3 stories$34,200.00
Fillmore Street12 units/3 stories$52,135.00
Folsom Street12 units/3 stories$67,000.00
Gough Street12 units/3 stories$80,000.00
Haight Street12 units/3 stories$100,000.00
Hoff Street12 units/3 stories$120,000.00
Jackson12 units/3 stories$45,000.00
Pacific Avenue12 units/3 stories$54,000.00
Polk Street12 units/3 stories$106,000.00
Valencia Street12 units/3 stories$50,000.00
6th Street13 units/3 stories$40,000.00
8th Street13 units/3 stories$30,000.00
Lombard Street13 units/3 stories$81,000.00
Market Street13 units/3 stories$60,000.00
Valencia Street14 units/3 stories$65,000.00
48th Avenue15 units/3 stories$135,000.00
Cervantes Blvd15 units/3 stories$105,000.00
Valencia Street15 units/3 stories$70,000.00
Hyde Street15 units/4 stories$85,000.00
15th Avenue16 units/3 stories$75,000.00
Capp Street16 units/3 stories$43,000.00
Divisadero Street16 units/3 stories$50,000.00
Pine Street17 units/2 stories$50,000.00
Beach Street18 units/3 stories$225,000.00
Broderick Street18 units/3 stories$90,000.00
Broderick Street18 units/3 stories$95,000.00
Francisco Street18 units/3 stories$28,000.00
Francisco Street18 units/3 stories$79,500.00
Mission Street18 units/3 stories$52,000.00
Chestnut Street21 units/3 stories$155,000.00
Albion Street22units/3 stories$50,000.00
Van Ness Avenue23 units/3 stories$81,000.00
20th Street24 units/3 stories$100,000.00
Chestnut Street24 units/3 stories$70,000.00
Valencia Street24 units/3 stories$137,000.00
Union Street30 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 TierSubmittal of Permit Application with Plans for Seismic Retrofit WorkCompletion of Work and Issuance of Certificate of Final Completion
1September 15, 2015September 15, 2017
2September 15, 2016September 15, 2018
3September 15, 2017September 15, 2019
4September 15, 2018September 15, 2020

Penhall Seismic Retrofit EngineerDoes 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.

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