On Friday, August 20, 2021, ICLR hosted a two-part webinar titled "The National Guide for Wildland Urban Interface Fires (Part 1), and an Impact Analysis of the National WUI Guide (Part 2).' Part two was led by Dr. Keith Porter, co-principal of SPA Risk LLC, an applied-research firm specializing in multihazard disaster risk to buildings and lifelines. Part 2: National WUI Guide Impact Analysis With NRC support, ICLR collaborated with SPA Risk LLC and several stakeholders to examine the impacts of following NRC’s WUI Fire Guide. Following the Guide for new construction can produce benefits that exceed the approximately $5/square-foot costs by 32:1, and more when one can rely on vegetation management. Retrofitting existing buildings, with somewhat higher costs, can save up to 14:1 in high-hazard locations. Application of the WUI Guide across Canada would add $125 billion to construction and retrofit costs over 10 years but avoid $500 billion in future losses, create 20,000 jobs, save 2,300 lives, avoid 17,000 nonfatal injuries, and protect $1 billion in tax revenues. The impact analysis suggests that the guide makes good financial sense for Canada.

1. What are the Benefits and Costs
of the National WUI Guide
ICLR August Forum
August 20, 2021
By Institute for Catastrophic Loss Reduction
and SPA Risk LLC
www.sparisk.com/pubs/Porter-2021-ICLR-Aug.pdf

2. Benefits and costs of the WUI guide
• Canada is suffering from the climate crisis
with steadily increasing WUI catastrophes
• Everybody pays, even those out of the WUI
• NRC produced this guide to build better
What are its costs and benefits?
What is the business case to follow the Guide?
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3. Authors, advisors, & reviewers
Keith Porter, Charles Scawthorn & Dan Sandink SPA Risk LLC & ICLR
Mark Alam and Rodney McPhee Canadian Wood Council
Ray Ault Canadian Interagency Forest Fire Ctr
William Brewer and Steven Hawks Cal Fire
Trevor Grieve Wawanesa Insurance
Kelly Johnston FireSmart Canada
Frank Lohmann Canadian Home Builders’ Association
Steve Taylor Natural Resources Canada
Kelsey Winter British Columbia Forest Service
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4. Outline
1. Objectives (1 min)
2. Methods (5 min)
3. Findings and conclusions of the impact analysis (5 min)
4. Possibilities for future implementation (10 min)
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5. Objectives
• Benefit-cost analysis of complying with WUI Guide
• Statistically representative existing buildings; 3 exposure levels
• Ditto, new building
• Scale up to community & national levels; include community costs
• Benefits by benefit category
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6. Products
5-page overview
https://doi.org/10.25810/4k6e-tf48
136-pp scholarly report
https://doi.org/10.25810/rxtc-3p87
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7. Methods
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• Sample 102 houses in 9 towns
• Span east-west, low-high hazard
• Choose 2 older, 2 newer typical cases
• Use new CAL FIRE ignition & loss data
• Estimate costs and benefits
• 15 options/house: 3 exposure levels x
5 vegetation-management options
• Add climate change & demand surge

8. Sampling: 11-12 houses/town = 102
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9. 8/20/2021 Institute for Catastrophic Loss Reduction and SPA Risk LLC 9
Retrofit house archetype mod-high
53.8280N, -101.2426E
3 bed, 2.5 bath
1 story, 1 basement
Built 1972
1,272 sq ft living area
2,030 roof area (incl. garage)
2,184 sq ft ext. wall area
218 sq ft windows
261 lf house perimeter
Comp roof, vinyl cladding
$486,000 RCN, contents $341,000, 2 occupants
$30,300 to retrofit

10. Compliance costs
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11. Community compliance
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Zone 3: 25 parcels
Zone 2: 7 parcels
Zone 1: 3 parcels

12. Hazard (burn rate)
Fire regime Burn rate
type (%·year
–1
)
1 0.0295
2 0.0970
3 0.7565
4 0.9918
5 0.2746
6 0.7327
7 0.0872
8 1.8097
9 0.0926
10 0.0700
11 0.5237
12 0.1132
13 0.0918
14 0.1654
15 0.0048
Note: assumes past climate (1970-2016)
Gaur et al. (2021) estimate significant increases
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13. Ignition probability
Pre-fire building inspection (Dspace) & post-fire damage (DINS) from 2018 Camp Fire, 1,065 houses
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14. Findings and conclusions of
the impact analysis

15. National BCR 4:1
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16. Benefit categories
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17. House-level BCRs over 30:1
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18. Community-level BCRs up to 14:1
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19. Cooperation, climate, & community matter
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20. There is more to the WUI story
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21. 10 Implementation ideas

22. 1. Tool for user-specific impacts
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23. 2. Incentives to align stakeholder interests
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24. 3. Guide to coordinate vegetation management
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25. 4. Nature-based practices
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26. 5. Address impacts on renters, disadvantaged groups
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27. 6. Reconcile fire vulnerability models
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Camp Fire
Fort McMurray

28. 7. Reconcile with NBC and other codes
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29. 8. Understand public service, emergency
response, historical, and cultural impacts
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30. 9. Understand non-residential buildings
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31. 10. Impacts on Indigenous & northern communities
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32. For more information
• This deck: www.sparisk.com/pubs/Porter-2021-ICLR-Aug.pdf
• A short video: https://youtu.be/1twinZrvxMc
• A long video: https://youtu.be/3cByALJgDMM
• 5-page overview report: https://doi.org/10.25810/4k6e-tf48
• 136-pp scholarly report: https://doi.org/10.25810/rxtc-3p87
kporter@sparisk.com, 1-626-233-9758
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