THE BUILDING ENVELOPE: Lecture 3

Building Codes and Standards

MODEL BUILDING CODES

• Establish standard of practice

• Represent “minimum” standards

• Must be adopted by local authority to be “legal”

MODEL BUILDING CODES

April 2000:

Uniform Building Code

Standard Building Code

BOCA/Basic Building Code

became

The International Building Code

INTERNATIONAL BUILDING CODE

• One national consensus model code

• Based on national consensus standard (ASCE 7)

• Will become standard of practice in foreseeable future as local jurisdictions formally adopt the IBC

INTERNATIONAL RESIDENTIAL CODE

• Replaces CABO “One- and Two-Family Dwelling Code”

• Residential buildings where V > 110 mph must be designed for loads in ASCE 7

• Requires that ~ one-half of new residential buildings in U.S. be “engineered”

ASCE 7

• National consensus standard

• Captures modern wind engineering technology

• Addresses factors judged to affect significantly the pressures that act on buildings in windstorms

ASCE 7: FACTORS THAT AFFECT PRESSURE

• wind speed (V)• terrain (Kz)• topography (Kzt)• wind direction (Kd)• wind gusts (G)• building geometry (Cp)• relative importance of the building (I).

NATIONAL CONSENSUS STANDARDS

ASCE 7: Minimum Design LoadsASTM: Wind Borne DebrisAISC/AISI: Steel ConstructionACI: Reinforced ConcreteNFPA: Timber ConstructionNCMA: Concrete MasonryMBMA: Metal BuildingsAAMA: Architectural Glazing

LOCAL BUILDING CODES

Formal enactment of laws or ordinances are necessary for legal enforcement of

Local Building Codes

• State Building Codes

• County Building Codes

• Municipal Building Codes

• Insurance Building Codes

PERFORMANCE AND PRESCRIPTIVE CODES

Performance Codes: Require the designer to meet specific performance standards (e.g., a specific design wind speed)

Prescriptive Codes: Prescribe construction details for the builder (i.e., if the builder conforms the building is deemed to be in compliance)

THE "EITHER/OR" OPTION

• The IRC and ASCE 7 offer the designer an option:

Design for (1) windborne debris (i.e. window protection) or (2) for

internal pressure

• Many designers opt for (2)

• Option 2 is often short sighted

BEYOND CODE MINIMUMS

• IBC/IRC and ASCE 7 establish minimum requirements

• Designer has responsibility to assess special project conditions that may warrant attention beyond code minimums

• Special design requirements may be established