ICC 1300 and Standard Plan: A Cost Comparison

Standard Plan A and ICC 1300: A Comparative Study

ICC 1300 is a-yet-to-be-published guideline published by the International Existing Building Code.  This study was written with a view to helping you the homeowner and California Building Departments decide if they want to keep using the universally accepted retrofit standard called Standard Plan A, which has been endorsed by the Northern Chapter of the Structural Engineer’s Association, all Bay Area building department, numerous local  chapters of the International Code Council, The Association  of Bay Area Governments, The Northern Chapter of the  Earthquake Engineering Research Institute, and the California Building Officials Association as well as the California Earthquake Bolt and Brace Program.  This standard will be compared to a new alternative  

The author was on both the Standard Plan A and ICC 1300 development committees and knows the guidelines well. 

Standard Plan A was created by a volunteer ad hoc group of engineers, building officials, and a contractor  at no expense to the taxpayer.  Standard Plan A is based on a study done by the National Science Foundation which predicted damage based on  actual damage statistics from both the Northridge and Loma Prieta Earthquakes as found on page 4 of this study. 

ICC 1300 started out as FEMA P-1100 in its rough draft until it was codified into ICC 1300 in 2024.  FEMA P-1100 was created by a group of  wood scientist and engineers using $22,400,000 in FEMA funded research grants, both directly and indirectly.  So far as the author can tell, its damage forecast damage scenarios are based on computer modelling and engineering theory as well as various lab tests and reports.  A list of these 21 lab tests and reports can be seen here.  

 

A LIST OF SOME OF THE RESEARCH FEMA PAID FOR TO DEVELOP ICC 1300

 

The most expensive of the research projects was the $12,000,000 CUREE Woodframe Project which was funded by FEMA after the Northridge Earthquake.  Its stated purpose was to provide testing results of which could then be used by engineers, contractors, and building departments “to significantly reduce earthquake losses to wood frame construction”.  The research was spear headed by scientists and engineers who had never crawled under a house, let alone retrofitted one. 

The result is that no  practicing engineer, building departments, or contractors know about this project, let alone use the 30 reports it generated. I suggest you call any contractor engineer, or building department to find out for yourself.   The question is, what did we as taxpayers get for our $12,400,000?

Comparison Between Standard Plan A And ICC 1300 Retrofits

An ICC 1300 retrofit is compared to a Standard Plan A for the same 1350 Square Foot 1-Story Light Construction House

Is The Engineering Rational in ICC 1300?  

The earthquake resistance of each component, i.e., the bolts, plywood, and L90s, should be more or less equal to create a balanced and money saving retrofit. The thinking behind this is that a retrofit is only as strong as its weakest connection. The plywood, bolts, and L90s work as a system. If one component fails the entire system fails. For example, in the ICC 1300 retrofit above the L90s can resist 18,000 lbs  of force on each wall line, the plywood 9,120 Lbs, and the bolts 23,125 lbs.  The retrofit will fail as soon as it must resist 9,120 lbs. of force provided by the plywood; anything over that in the L90s and plywood  earthquake resistance is redundant and a waste of money.  In this case  all 4 wall lines total 56,020 lbs. of excess bolts ($2,875.00) and 35,120 lbs. of excess L90s ($1,480.00).  This exceed hardware translates into $4,355.00 of excess cost.   Here is a 3:40 video that explains how balanced retrofits work.

A 1350 Square Foot 1-Story Medium Construction Comparison

These two figures compare an ICC 1300 retrofit (on the left) with a Standard Plan A retrofit (on the right) for a medium construction 1,350 square foot house. A Standard Plan A retrofit will cost $6,644, compared to $17,784 for a ICC 1300 retrofit. Notice how grossly out of balance the ICC 1300 retrofit is. The 21,000 lbs. of bolt capacity in p-1100 exceeds the 11,760 lb. plywood capacity by 9,240 lbs on each wall line for a total of $4,320.00 excess cost when the excess on all four wall lines are added together. We also find 15,065 lbs. of excess  L90 capacity on each wall line (60.260 lbs. when all four wall lines are added together) for a total of 65 excess L90s  ($3,198). These excess bolts and L90s cause this P-1100 retrofit to be far more expensive than it needs to be.

On the other hand, the Standard Plan A retrofit is balanced with 6,600 lbs. of plywood, 6,000 lbs. worth or bolts, and 6,475 lbs. of L90s on each side. This balanced Standard Plan A retrofit costs considerably less because it is balanced.

A 1350 Square Foot 1-Story Heavy Construction Comparison.

Again, notice how grossly out of balance the ICC 1300 retrofit is.

Comparing ICC 1300 and Standard Plan A 2-story Retrofits

ICC 1300 two story retrofits use the same EARTHQUAKE RETROFIT SCHEDULE as 1-story houses. The only difference is that these retrofits often use holdowns, (called tie-downs in the table), which resist overturning forces.

A 3150 Square Foot 2-Story Light Construction Comparison

Applying the same thinking process we used in evaluating 1-story houses shown below, we see the ICC 1300 retrofit on the left will cost $49,384, compared to a $9,158 Standard Plan A retrofit shown on the right. 

Again, notice how grossly out of balance the ICC 1300 retrofit is where the capacity of the plywood is 18,240 lbs., the bolts almost twice that amount at 18,240 lbs., and the L90s almost three times that amount at 44,000 lbs. All of this excess increases costs immeasurably. 

Compare this to the almost perfectly balanced Standard Plan A retrofit with 8,800 lbs. of plywood, 9,000 lbs. worth or bolts, and 9,250 lbs. worth of L90s on each wall line.

Notice how the available foundation on the P-1100 retrofit is less than the linear footage of plywood required by ICC 1300. In my experience with designing seismic retrofits for two story houses, which are invariably rectangular, I cannot think of a single instance where P-1100 will work on a two story house.   This will be the case even if the house is a perfect square. 

3150 Square Foot 2-Story Medium Construction Comparison

Assuming 2-story houses where ICC 1300 will work actually exist, when we apply the same thinking process used for 1-story houses to this house we discover that this ICC 1300 retrofit will cost $47,284 compared to a $22,530 Standard Plan A retrofit. The same problem with balance applies here. Notice how the Standard Plan A retrofit is almost perfectly balanced.

3150 Square Foot 2-Story Heavy Construction Comparison

When we apply the same thinking process to this house we discover that the ICC 1300 retrofit will cost $55,276 compared to a $24,392 Standard Plan A retrofit. The same problem with balance applies here.

No Cripple Wall Retrofits

Here we compare a 2-story 3,150 square foot medium construction P-1100 retrofit of a house without cripple walls. In this retrofit we are using the Type B Connector (the brand name is the Simpson Strongtie FRFP) from the EARTHQUAKE RETROFIT SCHEDULE which is  ICC 1300 approach and compare it to a 3,150 square foot 2-story Standard Plan A retrofit no cripple wall retrofit (on the right) which uses the Simpson StrongTie URFP. The ICC 1300 retrofit will cost $42,793, compared to a $6,438 Standard Plan A retrofit.

In this last part of our study we look at what happens when a ICC 1300 construction detail seen on the lower right is applied to a medium construction 1,350 square foot single story house. A construction detail is a drawing that shows a contractor how to build something.

The dark and light blue lines in the detail are 4 foot long shims called “runners”. The red lines are Type B Connectors (Simpson FRFPs). This is another case where the linear footage of foundation is not long enough for the length of the plywood required by the EARTHQUAKE RETROFIT SCHEDULE. The detail has many other problems, including a building code violation. This is fully described in this video.

 Reading The Tables In ICC 1300 And Standard Plan A

Both guidelines require the user to consult table that tell the user how much hardware and how many linear feet of plywood one should used base on the total floor area and the construction type.  Notes on the page define whether or not the construction type is heavy or light in Standard Plan A or heavy, medium, or light with ICC 1300. 

TABLE FROM STANDARD PLAN A THAT SPECIFIES EXACTLY WHICH SIMPSON HARDWARE SHOULD BE USED SUCH AS THE UFP10, H1,L90 ETC. 

This makes Standard Plan A user friendly because one can go to any hardware store or builders supply and ask for precisely what one needs. 

ON THE OTHER HAND, ICC 1300 DOES NOT SPECIFFY THE HARDWARE. .  INSTEAD IT HAS IMAGES THAT REMOTELY RESEMBLE THE SIMPSON HARDWARE THEY ARE SUPPOSED TO REPRESENT.  THE TYPE A CONNECTOR IS THE SIMPSON UFP AND BARELY LOOKS LIKE A SIMPSON UFP.  THE TYPE B CONNECTOR IS THE SIMPSON FRFP WHICH CONTRACTORS NEVER USE, AND THE TYPE C CONNECTOR IS THE OLD SIMPSON FA8 WHICH IS NO  LONGER EXISTS. 

     You can imagine the frustration of someone looking for a Type A Connector (The Simpson UFP)  and the only thing one has is this less than accurate representation of this hardware.  Imagine showing a Home Depot sales clerk this rudimentary drawing and asking where to find it in the store.  The salesperson  would have no idea what the hardware is, let alone know where to find it.  Imagine going to a builders supply and doing the same with the Type C connector (The non-existent Simpson FA8).  A salesperson cannot find hardware that no longer exists.  And finally imagine the frustration if a contractor happens to find the Type B Connectors (these are the Simpson FRFP and available special order) only to discover they are not used by seismic retrofit contractors. 

This lack of specificity is a fatal flaw makes this guideline more or less unusable and contractors will stay aware from it. 

How Has FEMA’s $22,400,000 In Research Helped Contractors Who Are The First Line Of Defense?

It appears to this contractor that the ATC funded structural engineers used this money to esoteric reports with images and tables like those shown below that do nothing to help the contractors and  protect the public. Having never done residential seismic retrofits themselves, they did not know what kinds of tests would be useful.  

IMAGES FROM TEST REPORTS FOUND IN VOLUME 3 OF FEMA P-1100 WHICH WAS THE BASIS OF ICC 1300. 

What Else Increases Cost?

In addition ICC 1300 specifies the use of Type H Connectors which strengthen a connection that has historically never failed. A full description of it can be seen here.  This will add another $1000 or so to every ICC 1300 retrofit.  ICC 1300 has numerous inefficiencies, most of which are listed on this video page. 

 

 

 

Conclusion

The committee that wrote the progenitor of ICC 1300 (FEMA P-1100) did not have any contractors on the committee which is reflected in its impracticality and high cost.  The committee was analogous to a group of aeronautical engineers writing a manual on bicycle riding when they had never ridden one themselves.  This lack of practical experience had the following consequences. 

• The average average homeowner will not be able to afford ICC 1300 retrofits. 
• Builder’s Supply houses, Home Depot, and the contractors themselves will not be able to identify the hardware specified.
• Imbalanced engineering increases the cost.  Contractors never use imbalanced engineering because it costs them money.  
• The anticipation of high lateral forces was based on computer modelling rather than the empirical evidence used by Standard Plan A increases cost.  
• These high forces make ICC 1300 impossible to use on two story homes where it is impossible to use even if the building is a perfect square. 

Solutions For The Seismic Retrofit Industry

The  most sensible thing to do would be to revise the tables and include contractors who understand cost and the needs  of the average homeowner before the next code cycle.   In addition, Standard Plan A, should be revised.  The most important cost-saving revisions can be seen here. 

Who Wrote ICC 1300?

Here is a list of the people (mostly engineers) who authored FEMA P-1100 before it was edited into ICC 1300.   This is a group of highly distinguished scientists and engineers from all over the country.  Unfortunately, none of them were contractors with practical experience in the field. 

ICC 1300 In The Real World

These 3 simple guidelines address cripple walls retrofits where the cripple walls are less that 4 feet tall.  ICC 1300 addresses cripple walls over 4 feet tall in the most complicated and expensive manner possible.  Homes with cripple walls over 4′ tall can be designed just like any other cripple wall retrofit except Simpson HDU2 holddowns need to be installed on the ends of the shear walls to prevent overturning.  All the engineered designs we see in the Bay Area do it this way.  You don’t need to know much more than that.

ICC 1300 Chapter 4: Cripple Wall Retrofit Soft Costs.

It costs the average contractor $800 to produce a bid using ICC 1300’s complicated preliminary evaluation process.  This is necessary just to see if ICC 1300 can be used. If it can be used, creating a proposal costs another $400 in time.  A contractor must charge the homeowner up front to cover these costs.  The much simpler Standard Plan A or Chapter A3 retrofits cost $300 to create for both the evaluation and proposal.   Most homeowners are sympathetic to a contractor’s soft costs and are willing to pay this $300 up front fee.  When homeowners are told they need to pay $1200 for the ICC 1300 evaluation, they will go somewhere else. 

What if I Still Want To Use ICC 1300?

In order to use ICC 1300 for a cripple wall retrofit one must understand how to use the tables in Chapter 4.  That is key. This video will tell you everything you need to know.  

s. 

HOW TO USE THE TABLES IN ICC 1300

 

Impact Of Base Shear On ICC 1300

Standard Plan A retrofits use a simple engineering formula  V (base shear) =0.186 x W (weight)  as specified in Standard Plan A’s calculations.  Base shear is the amount of lateral shear a house must resist at its based  measured in pounds.  The heavier the weight the higher the base shear and the more retrofit components are needed to resist this higher lateral force. 

I asked one of the scientists as if  ICC-1300 was using a higher base shear of if the building weights were much higher.  Higher base shear and house weights would explain the cost difference. This is the answer I received.    I do not understand most of the technical terms.

“I think the LOG (living area above a garage) retrofits use an R of 5.0 (which is more restrictive than ASCE 7 where wood structural panel shear walls have an R of 6.5). The seismic response coefficient Cs = Sds/R = 1.25/5.0 = 0.25 and the base shear is 0.250w. For Standard Plan A the Cs is 0.186, thus  ICC 1300 is generating a base shear 1.34 times that of Standard Plan A.

Interestingly 1.25/6.5 = 0.192 which is still a bit higher than 0.186. Not sure what Standard Plan A is assuming? Maybe Sds=1.17 which used to be the trigger for SDC E in the IRC. Which gets you Cs=0.180 for R=6.5, close to Standard Plan A’s 0.182.

I forget whether ICC 1300 adjusted the resistance side for Living Area Above a garage retrofits too or applied other factors. There was that 1.5 factor Phil Line was concerned about with cripple walls because it was making the results more conservative than a complete engineered design using ASCE 7 and AWC’s standards.

The weights are higher, but I’m not sure that is entirely responsible for the difference. P-1100 is 18% higher on the roof weight (13psf vs 11psf for a light roof assembly) and 33% higher on the floor weight (12psf vs. 9psf for a light floor assembly). And P-1100 isn’t entirely unreasonable as assumptions go, it tracks with other industry resources like the HUD Residential Structural Design Guide.

Put that weight together with the 34% increase in the respective Cs values and you’re getting to a 60-70% increase in base shear. But we know there are other conservative assumptions embedded deep in P-1100’s modeling and calculations. I haven’t spent anywhere near enough time rooting around under the hood to find them.

This unlocks most of the mystery.  From what I can tell ICC 1300 is working with a base shear of 0.316 – 0.35 which is nearly double that of Standard Plan A. This accounts in part for the two fold cost of ICC 1300 over Standard Plan A. 

Follow The Money From FEMA To ATC And The Structural Engineers

The ICC 1300 project was organized by the Applied Technology Council who must have convinced FEMA to provide funding for this project.  Here is the description of the ATC found in Wikipedia.

“The Applied Technology Council is a nonprofit research organization based in California which studies the effects of natural hazards on the built environment and how to mitigate these effects, particularly earthquakes. It was founded through the efforts of the Structural Engineers Association of California in 1973.^[1] It does not develop building codes but does develop manuals which summarize information for engineers, and this information is sometimes used in codes, standards, and specifications. Its main purpose is to create publications. 

Notice the ATC is a non-profit which means its survival depends on grants.   Therefore,  it would be natural for it to seek grants from the deep pockets of the Federal Emergency Management Agency.  The ATC relies on these grants to pay their salaries.  Once their salaries are the paid rest will be allotted to members of the Structural Engineers Association who founded the Applied Technology Council.  This is how the money circulated from FEMA. 

THE CIRCULATION OF GRANT MAONEY PROVIDED BY THE FEDERAL EMEGENCY MANAGEMENT AGENCY

The structural engineers design very few cripple wall retrofits let alone install them. Cripple wall retrofits take engineers out of their comfortable offices, require them to get dirty, pays little, and the liability is astronomical.   However, if you give them $22,400,000 to spend with none of these constraints so they will figure out a way to spend it so they set up labs to run tests that produce graphs and reports like these that are of absolutely no use to those who design and install residential seismic retrofits and do nothing to protect the public. 

 FEMA has good intentions. the ATC has good intensions, the Structural Engineers Association has good intentions, the engineers who wrote ICC 1300 had good intentions, and the unpaid volunteers who tried to make something contractor friendly had the best intentions of all.  However, if from the start someone hands 3 million dollars to a group of engineers who are believed to understand seismic retrofitting and tells them to spend it on a particular topic of interest, they will find a way to spend it no mater how pointless and academic it may be.

This may be a cynical way of looking at this, but I think the ICC 1300 evolution process worked something like this: 

The Applied Technology Council convinced FEMA that the public needed a new seismic retrofit guideline drawing on the millions of dollars of research FEMA had already paid for but more research was still needed.    Once FEMA gave them the green light along with a few million more dollars in additional funding, large sums of money were given to the Structural Engineer’s Association which also paid the salaries at the ATC so they could apply for more grants from FEMA a few years later and the cycle starts all over again.

Once the ATC gets a grant they skim off part of it to fund their organization and give the rest of the money to engineers to develop a guideline.  FEMA P-1100’s predecessor FEMA DR-4193-RA2 Earthquake Strengthening of Cripple Walls in Wood Frame Buildings admits as much:

ICC 1300 Is Just One More Failed Guideline

ICC 1300 is just one more guideline that failed the practicality, affordability, and sound engineering  tests and will be relegated to the long list of FEMA funded earthquake retrofit related literature which no one will ever hear of, let alone use.  In the future the ATC will convince FEMA that ICC 1300 is unaffordable and impractical, which is obviously true, and convince FEMA to fund  a new guidelines that will be just as unusable. Ten years later it will start all over again with a few different faces and another FEMA guideline will be born. It is interesting to note that the practicing engineers and contractors I know do not use any of the long list of FEMA funded guidelines mentioned above for the exact same reason none of the will use ICC 1300. 

The Solution: Go From Practice To Theory.

ICC 1300 starts in the theoretical world of computer models and imaginary engineering conjecture and tries to apply this to a real world crawl space which the computers and engineers have never, or in the case of engineers maybe 1 or 2 have very minimally seen first hand.  This is reflected in the fact that ICC proves itself to be awkward and in some cases such as the its application to two-story homes impossible to use.  If the committee had started with actual two-story homes it would be quickly apparent that ICC 1300 can never apply to two-story homes no matter how they are built.   Once this became apparent all the tables that address two-story homes would be scraped and turned into something that could actually be applied.  What happened here is very much like a team of Ph.D. mechanical engineers writing a book on how to build a sewing machine when no one on the committee has ever seen a dress or shirt. If they had started with a shirt and then figured out how to make a machine that would create one they would likely be successful. 

 A an approach that would certainly be more successful would be to go from the real world into the theoretical world.  this would mean taking houses apart, seeing what the existing connections are made of, doing research regarding damage in previous earthquakes, and then strengthen those connections.  Once these connections were strengthened the methods used would  become part of the guideline.  In addition, we would make sure it was affordable no matter how much a person could afford and offer the public different levels of protection and cost based on the quantities of hardware and linear feet of plywood required.  This information would become the the bulk of the planset.  The planset could also include a series of details  that could be downloaded from the internet that not only illustrates the  the detail itself but also contains a link at the bottom of the page like this one that links to a video that shows a contractor how to build it.  This could be done for less than $100.000 and save FEMA from spending many millions more on the next grant to the ATC. 

The oversight from engineers would still have a place to make sure the engineering, unlike ICC 1300, is balanced and sound.   As we saw, imbalanced engineering has a significant impact on cost and must be analyzed carefully.  

How This Study Was  Done

The most effective way to conduct this study was to apply the two guidelines to an identical house where the existing construction materials, square footage, and weight of the house are the same.

Throughout this study the pricing per piece of hardware and price per linear foot of plywood is based on Bay Area Retrofit’s current price schedule shown below.

 

Pricing
5/8” Bolts		$77 each
URFP		$135 each
FRFP		$135 each
L90		$39 each
Plywood <  4 feet		$90 plf
Plywood >  4 feet		$165 plf
Tie Downs		$215 each

The Earthquake Resistance of Plywood and Hardware

The table below contains the earthquake resistance of the plywood and hardware used in this study.  These values are derived from APA Research Report 154, the National Design Specification, and the Simpson StrongTie Catalog. 

Capacities
5/8” Bolts in 2” Close Grain Redwood		1500#
URFP		1530#
FRFP		960#
L90		925#
Light Construction Rated Plywood		380plf
Medium Construction Rated Plywood		490plf
Standard Plan A 3” o.c. Structural 1 Plywood		550plf
Heavy Construction Rated Plywood		640plf

House Weights

House weights along with the base shear formula tell us how much hardware and plywood we will need.  Mr. Jim Russel P.E. figured out precisely how much hardware and plywood will be needed by using a simple formula described in these videos.   These are the weights he used depending on how the house was built.

These Are the Weights In Standard Plan A Per Square Foot And Category.  I do not know the weights used in ICC 1300

Shingle roof, wood siding, and sheet rock inside.  This is light construction

 One Story

 34# per square foot

Two Story

29.5# square foot

 

Shingle roofing, wood siding, and plaster inside.   This is medium construction

One Story

45# per square foot

Two Story

41# per square foot

 

Shingle roofing, stucco exterior, and sheet rock inside.   This is also medium construction

 One Story

41# per square foot

Two Story

36.5# per square foot

 

Shingle roofing, stucco exterior, and plaster inside.  This is heavy construction

One Story

 50# per square foot

Two Story

45# per square foot

House weights used in ICC 1300 are unknown.  

 

Below is a list of FEMA funded Applied Technology Council Publications that gives an idea of how much public money has been spent on government publications which no one uses that address the seismic retrofit of homes.   There are a total of 298 publications.  Below are the ones that pertain to residential retrofitting that I could find.  I am sure there are more.  Applied Technology Council Publications

FEMA P-50 Simplifed Seismic Assessment of Detached,Single-Family Wood-Frame Dwellings

FEMA P-50-1 Seismic Retrofit Guidelines for Detached, Single-Family, Wood-Frame Dwellings

ATC-14-TOC Evaluating the Seismic Resistance of Existing Buildings

FEMA P-547  Techniques For The Seismic Rehabilitation of Existing Buildings

PEER Framing Hillside Home Retrofit Decisions

FEMA 276, Example Applications of the NEHRP Guidelines for the Seismic Rehabilitation of Buildings

FEMA DR-4193-RA2 Earthquake Strengthening of Cripple Walls in Wood Frame Buildings. 

PEER Research Studies for P-1100 Retrofit of One and Two-Story Dwellings

FEMA 232 Homebuilder’s Guide to Earthquake Resistant Design and Construction

FEMA P-58-1, Seismic Performance Assessment of Buildings, Volume 1 – Methodology, Second Edition

Calfiornia Earthquake Authority Earthquake Damage Assessment and Repair Guidelines for Residential Wood-Frame Buildings

FEMA ABAG Training

FEMA P-58-2, Seismic Performance Assessment of Buildings, Volume 2 – Implementation Guide, Second Edition

ATC-28, Development of Guidelines For Seismic Rehabilitation of Buildings. 

FEMA_274, NEHRP Commentary on the Guidelines for the Seismic Rehabilitation of Buildings

FEMA ABAG Training

ATC-50TOC Simplified Seismic Assessment of Detached, Single-Family, Wood-Frame Dwellings

FEMA: P-1100 Vulnerability – Based Seismic Assessment and Retrofit of One and Two-Story Dwellings

FEMA P-1100 2A Plan Set

A Methodology for Seismic Design and Construction of Single-Family Dwellings

FEMA P-1100 2B Plan Set – Living Area Above a Garage. 

FEMAP-1100-Vol2B-Planset-LOG

FEMA Hawaii Retrofits

Are Any Of These Guidelines Useful?

The real world of retrofitting is far removed from these highly impractical FEMA publications.

Criticisms Welcome

If anyone disagrees with this analysis please write to me and I will publish it here.