Building Codes: Where we are and where we're going

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Building Codes Where we are and where we're
going
Are you sitting down?

• 2008 IBHS Annual Conference on Property Loss
  Reduction
• Randy Shackelford
• Simpson Strong-Tie Co.

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Natural Hazard Map
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Wishful thinking?
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Where We Are

• Good news
• Model codes do good job
• Standards (basis) are scientifically based
• Enforcement good in some areas
• Designers qualified in most cases

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Where We Are

• Bad news
• Model codes frequently modified
• Enforcement not so good in some areas
• Designers not qualified for most common structure
• Their lobbyists are better than your lobbyists

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Model Codes

• Two types of model codes
• Performance Code (IBC)
• Typically based on National Consensus Standards
• Prescriptive Code (IRC)
• Chance to water down consensus standards when
  converting to prescriptive
• IRC Code committee different from IBC committee
• Battle starts where codes are written

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IRC Wall Bracing

• Wall bracing keeps house square
• Based entirely on seismic forces
• ICC committee worked past two years
• NAHB has practical veto power
• Result was watered down so it would pass

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Model Code Adoption

• Code does not become law until officially
  adopted by authority having jurisdiction
• Political pressure more effective on local level
• Several ways codes can be/are weakened when
  adopted

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Weaken 1

• Technical amendments to codes
• Stair geometry
• Handrail/Guardrail rqmts
• FIRE ISSUES
• Sprinklers
• Carbon Monoxide detectors
• Arc-Fault Circuit Interrupters
• Wind-related amendments
• Windborne debris
• Roofing

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Which building material is most prone to failure?

• R301.2.1 Wind limitations. Buildings and portions
  thereof shall be limited by wind speed, as
  defined in Table R301.2(1) and construction
  methods in accordance with this code. Basic wind
  speeds shall be determined from Figure R301.2(4).
  Where different construction methods and
  structural materials are used for various
  portions of a building, the applicable
  requirements of this section for each portion
  shall apply. Where loads for wall coverings,
  curtain walls, roof coverings, exterior windows,
  skylights, garage doors and exterior doors are
  not otherwise specified, the loads listed in
  Table R301.2(2) adjusted for height and exposure
  using Table R301.2(3) shall be used to determine
  design load performance requirements for wall
  coverings, curtain walls, roof coverings,
  exterior windows, skylights, garage doors and
  exterior doors. Asphalt shingles shall be
  designed for wind speeds in accordance with
  Section R905.2.6.

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Shingle Exception

• 905.2.6 Attachment. Asphalt shingles shall have
  the minimum number of fasteners required by the
  manufacturer. . For roofs located where the
  basic wind speed per Figure R301.2(4) is 110 mph
  or higher, special methods of fastening are
  required. Special fastening methods shall be
  tested in accordance with ASTM D 3161, Class F.
  Asphalt shingle wrappers shall bear a label
  indicating compliance with ASTM D 3161, Class F.
• Exceptions Asphalt strip shingles shall have a
  minimum of six fasteners per shingle where the
  roof is in one of the following categories
• 1. The basic wind speed per Figure R301.2(4) is
  110 miles per hour (177 km/h) or greater and the
  eave is 20 feet (6096 mm) or higher above grade.
• 2. The basic wind speed per Figure R301.2(4) is
  120 miles per hour (193 km/h) or greater.
• 3. Special wind zones per Figure R301.2.(4).

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Weaken 2

• Modify windborne debris requirements.
• Changing the area where windborne debris
  requirements apply
• Changing definition of windborne debris region
• Changing location of windspeed lines
• Deleting requirements altogether

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ASCE Windborne Debris Region
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North Carolina Residential Code (06)

• WIND BORNE DEBRIS REGION. Areas within
  hurricane prone regions within 1500 feet of the
  mean high water line of the Atlantic Ocean

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North Carolina Building Code (09)

• WIND-BORNE DEBRIS REGION. Areas within
  hurricane-prone defined as that area east of the
  inland waterway from the NC/SC State line north
  to Beaufort Inlet from that point to include the
  barrier islands to the NC/VA State line.

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120 MPH Windspeed Counties
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Weaken 3

• Modify windspeed lines.
• Reduces the area where increased wind design
  requirements would apply.
• Can affect windborne debris regions
• Similar - changing the minimum windspeed where
  wind design starts to be required.

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Weaken 4

• Developing watered down prescriptive
  requirements.
• National standards exist that give prescriptive
  methods for building light-frame (wood or steel)
  structures in high wind areas.
• Many states and some cities have developed
  alternate prescriptive methods in the name of
  simplification, which actually simply reduce
  requirements for wind resistant construction.

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Prescriptive Rqmts

• Justification
• Existing prescriptive standards outdated
• Standards too complicated
• Examples
• Florida engineering based
• Rhode Island
• Connecticut
• North Carolina
• City of Houston

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North Carolina Residential Code

• R301.2.1.1 Design criteria. Construction in
  regions where the basic wind speeds from Figure
  R301.2(4) equal or exceed 110 miles per hour
  (177.1 km/h) shall be designed in accordance with
  one of the following
• 6. High wind chapters 44 and 45

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Rhode IslandTriple Whammy

• Decreased wind designs
• Moved wind-speed contours seaward
• Reduced wind-borne debris protection
• Wind Zone 3 only
• No protection for bay areas
• Reduced prescriptive rqmts

Model code 110 mph
Model code 120 mph
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Weaken 4

• Update codes without updating technical design
  requirements.
• Update codes but allow older codes to be used as
  an option
• Memphis/Shelby County
• Adopted IBC
• Allowed 99 Standard Building Code as an option
• Building owner chooses which to use

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Weaken 5

• Delay adoption of newer codes.
• Completely delaying consideration of code updates
• Asking for cost-benefit studies of adopting newer
  codes
• Always show benefits
• Results in delay
• South Carolina
• Texas Department of Insurance

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Weaken 6

• Just dont adopt codes.
• Several states no state codes at all
• Some states only codes in certain counties
• MS Only 4 coastal counties
• Other states dont require that cities/counties
  adopt the state code
• MD

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Weaken 7

• Finally, regardless of which codes are adopted,
  unless they are enforced in the field, there will
  be no difference in construction. There needs to
  be a conscious effort on the part of
  jurisdictions to enforce new requirements and
  educate contractors and designers on them.

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Good News

• Florida now matches IBC/ASCE 7

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Good News

• Texas now has inspection in its counties
• TDI has increased windborne debris requirements
• Bad news
• Not by government
• Inspector hired by builder
• Only three inspections

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• THANK YOU