The FireHard system is a voluntary framework based on current best practices. It is not a building code, regulation, or mandatory standard.

FireHard Canada

Global Wildfire Construction Standards Compared

How FireHard WER compares to the NRC National Guide, Australian AS 3959, the US International Wildland-Urban Interface Code, and California Chapter 7A.

Five systems worldwide address wildfire-resistant construction. Each takes a different approach to risk assessment and building response. This comparison identifies where they converge, where they differ, and what FireHard WER adds to the Canadian context.

FireHard WER

Canada
4 WER levels + 3 CNEL tiers
Per-building + per-face assessment
Voluntary

NRC National Guide

Canada (NRC 2021)
4 exposure levels + 4 construction classes
Fuel-type + distance matrix
Voluntary

AS 3959:2018

Australia
6 BAL levels (LOW to FZ)
Quantitative radiant heat (kW/m²)
Mandatory | Paid ($)

IWUIC 2024

United States (ICC)
3 hazard classes
Defensible space + ignition resistance
Model Code

Chapter 7A

California (CBC)
Single standard (no tiers)
Ignition-resistant construction
Mandatory in WUI

Exposure Level Mapping

Approximate equivalencies between systems. Direct comparison is imprecise because each system uses different assessment methodology, but the construction response at each level is broadly comparable.

FireHard WER
WER-1 Ember <10 kW/m² WER-2 Radiant 10-19 kW/m² WER-3 High 19-40 kW/m² WER-4 Extreme >40 kW/m²
FireHard CNEL
CNEL-1 (6-10m) CNEL-2 (3-6m) CNEL-3 (<3m)
NRC Guide
Nil Ember-Only Low / CC3 Moderate / CC2 High / CC1 High / CC1(FR)
AS 3959 BAL
BAL-LOW BAL-12.5 BAL-19 BAL-29 BAL-40 BAL-FZ
IWUIC
Class 3 (Moderate) Class 2 (High) Class 1 (Extreme)
CA Chapter 7A
Single ignition-resistant standard (all WUI zones)

Feature-by-Feature Comparison

Feature FireHard WER NRC Guide AS 3959 IWUIC CA Ch. 7A
Risk assessment Site-specific vegetation + separation distance FBP fuel type + distance (simplified or 2km detailed) Vegetation + slope + FDI + distance = kW/m² AHJ hazard classification State Fire Marshal zone designation
Structure-to-structure fire ✓ CNEL system — 3 tiers, per-face, detailed specs Briefly acknowledged Structures included in BAL assessment Mentioned in context Not addressed
Slope adjustment ✓ Functional — slope factor modifies effective WER level Zone size adjustment ✓ Explicit tables by degree AHJ discretion Not explicit
Radiant heat metric ✓ Estimated kW/m² overlay mapped to AS 3959 thresholds Qualitative ✓ Quantitative kW/m² Qualitative Test-standard-based (ASTM)
Vegetation trade-off Separate system (references FireSmart) ✓ Explicit — more veg mgmt = lower CC ✓ Integral to BAL ✓ Defensible space zones 100ft defensible space required
Construction detail ✓ Specification-grade — 6 modules + 3 TBs General recommendations by CC ✓ Detailed by BAL per element Ignition-resistant class specs Prescriptive by element + test standard
Wall assembly design ✓ Full layered assembly (TB-01) Cladding classification only Cladding + subframe by BAL Ignition-resistant classification ASTM E2707 wall penetration test
Hot roof / unvented attic ✓ Recommended (TB-01, TB-03) Not addressed Not addressed Not addressed Not addressed
Sarking membrane ✓ Specified (TB-01, TB-03) Not addressed ✓ Required BAL-19+ Not addressed Not addressed
Wildfire shutters ✓ Specified by level Not addressed ✓ Required BAL-40+/FZ Not addressed Not addressed
Ember-resistant vents ✓ ASTM E2886 WER-2+ ✓ Required by CC ✓ Required BAL-12.5+ ✓ Required ✓ ASTM E2886
Decks and attachments ✓ Detailed (Module 4, TB-03) General recommendations ✓ By BAL level Ignition-resistant ✓ ASTM E2632/E2726
Fencing ✓ Detailed (Module 5, TB-02) General mention Not covered Defensible space context Not addressed
Community planning ✓ Community section (DPA, incentives, permits) ✓ Chapter 4 (roads, water, utilities) Referenced in state planning ✓ Access, water supply Defensible space zones
Emergency planning Province-level programs ✓ Chapter 5 (outreach, preparedness) State-level programs ✓ Fire department access Not addressed
Cost-benefit analysis Per-category cost estimates ✓ ICLR analysis ($4:$1 new, 30:1 BCR) General estimates ($10-15K BAL-12.5) Not published Not published
Insurance integration ✓ WER-rated discount framework Referenced in impact analysis Industry-level Not addressed Not addressed
Existing homes ✓ Self-assessment + retrofit guides ✓ Retrofit analysis by ICLR Focus on new construction Some retrofit provisions Applies to new + major reno
Free and accessible ✓ All docs free ✓ Free PDF Paid ($182 AUD) Paid ($) ✓ Free (UpCodes)
Maturity New (2025). No adoption. Building specification library only. Published 2021. Voluntary. Working toward standardisation and code adoption. Mature (1991, revised 2009, 2018). Mandatory in all states. 30+ years of enforcement. Established (2003, rev. 2024). Model code. Adoption varies by jurisdiction. Established (2008). Mandatory in CA WUI zones. Enforced statewide.

Unique Strengths and Gaps

FireHard WER

  • CNEL system (unique)
  • Specification-grade detail
  • Hot roof guidance (unique)
  • Insurance framework
  • Self-assessment for existing homes
  • Fencing research integration
  • kW/m² overlay (from AS 3959)
  • Slope adjustment factor
  • New, no adoption history

NRC Guide

  • Community planning chapter
  • Emergency outreach
  • ICLR cost-benefit data
  • National hazard mapping
  • Veg mgmt trade-off explicit
  • Limited construction detail
  • No wall assembly design
  • Structure-to-structure weak
  • No shutters or sarking

AS 3959

  • Quantitative kW/m² thresholds
  • Mandatory enforcement
  • Slope tables (explicit)
  • Decades of refinement
  • Sarking requirement
  • No separate close-neighbour
  • No hot roof guidance
  • Fencing not covered
  • No community planning

IWUIC

  • Integration with IBC/IRC
  • Fire department access
  • Water supply requirements
  • Defensible space zones
  • Paid access barrier
  • Adoption patchy
  • Limited detail per element
  • No structure-to-structure

CA Chapter 7A

  • Mandatory enforcement
  • ASTM test standards
  • Product listing (OSFM)
  • Applies to all WUI zones
  • Single tier (no graduation)
  • No structure-to-structure
  • No shutters
  • No wall assembly design

Key Takeaway

No single system covers everything. Australia leads on quantitative risk assessment and mandatory enforcement. Canada's NRC Guide leads on community planning and cost-benefit analysis. FireHard WER leads on construction specification detail, structure-to-structure fire (CNEL), and practical guidance for existing homes. The US systems are fragmented between IWUIC (model code) and state-level requirements like California Chapter 7A.

FireHard WER is designed to complement, not replace, the NRC National Guide. The NRC Guide provides the hazard framework and community-scale recommendations. FireHard WER provides the specification-grade construction detail that the NRC Guide deliberately leaves to others. Together they cover the full spectrum from national hazard mapping to individual fastener specifications.