Lecture Notes on Building Typologies and Code

Typologies

Components of Building Structure

• Gravity system, lateral system, and foundation system.
• Combining systems for different situations.

Responsibilities

• Architect's Responsibility: Building occupancy and construction (chapters 1-3 of IBC).
• Structural Engineer's Responsibility: Structural systems.
• Gray areas exist, requiring collaboration.

Governing Documentation

• Steel: Steel Manual (AISC).
• Concrete: ACI 318 document.
• Wood: National Design Specification (NDS).
• These documents are referenced by the International Building Code (IBC).

International Building Code (IBC)

• Prescribes safe building planning for egress and fire prevention.
• Tells you how to safely plan for a building space wise and what you have to do to prevent fire from risking more loss of life than it may have to.

General Breakdown of IBC

1. Chapters 1-4: Building occupancy and construction.
2. Chapters 4-15: Life safety and building science.
   • Egress, fire protection, or a mix of both.
3. Chapters 16-26: Structural systems or building materials.
   • Chapters 16-18: Loads, foundations.
   • Chapters 18-26: Individual materials like steel (referenced to AISC 360), aluminum, and glazing.
     • Glazing and Aluminum are envelope components designed by manufacturers, not the Engineer of Record (EOR).
4. Chapters 27-33: Miscellaneous (mechanical, electrical, plumbing).

Focus for Architecture and Structural Engineering

• First 26 chapters, especially chapters 1-3 for architects.

Construction Complexity and IBC Limitations

• The IBC imposes limitations on construction based on material, area, and height.
• Table 601 indicates the location of this information in Chapter 6.

Factors Influencing Construction Type

1. Occupancy Types: Program or planned use of the building.
2. Construction Type: Determined after occupancy type is defined.

Occupancy Types

• Categories defined by IBC with similarities to live loads.

Occupancy Categories

1. High Hazard (H): Flammable or explosive materials; requires specific fire protection.
2. Utility and Miscellaneous (U, M): Spare categories.
3. Assembly, Education, Mercantile (A, E, M): Yellow category.
4. Business, Institutional, Residential (B, I, R): Blue category.
5. Factory, Industrial, Storage (F, I, S): Orange category.

Blue Category (Light to Medium Loads)

• Hotels, multifamily housing, office buildings.
• Institutional: Places where people are cared for (retirement homes, hospitals, prisons).
• Residential: Single-family homes, multifamily condos, high-rise residential buildings.
• Business: Primarily office spaces.
• Low occupant load.

Yellow Category (High Occupant Load)

• Assembly: Civic spaces like airport terminals, shopping malls, convention centers.
• Education: Schools with assembly halls and gymnasiums.
• Mercantile: Places where people are selling things.
• Mixed Use: Buildings with multiple occupancies (e.g., food court and classrooms).
  • Loading is separated by occupancy type for structural engineering.

Orange Category (Low Occupant Load, Heavy Objects)

• Data centers, warehouses, factories with heavy machinery.
• Parking garages.
• Occupant load is low, but objects are heavy.

Load Considerations

• Not just about the weight; IBC considers the contents of the building.
• Live load ranges:
  • Blue: $50 <br /> ewline PSF$
  • Yellow: $100 <br /> ewline PSF$
  • Orange: $150 <br /> ewline PSF$
• The code always plans for the worst-case scenario.
• $Mean weight$ Equation example:
  • $Number <br /> ewline Of <br /> ewline Student = 24$
  • $Mean <br /> ewline Weight= 140$
  • $Total = 3,400 <br /> ewline pounds <br /> ewline in <br /> ewline order <br /> ewline to <br /> ewline get a <br /> ewline pressure <br /> ewline of <br /> ewline 100 <br /> ewline PSF$
  • $Students * Space = 6ft * 6ft$

Limits to Construction (Chapters 3-6)

• Occupancy (Chapters 3-4).
• Specific Use Cases (Chapter 4): Nuclear power plants, airplane hangars, tall atriums.
• Construction Type (Chapter 5): Limitations on height and area.

Construction Type Determination

• Based on occupancy, allowable height, and allowable area.
• Combustibility limits: Non-combustible, heavy timber, or light frame wood.
• Table 504: Allowable heights based on occupancy and construction type.
• The code gives a number of stories with sprinklers (S) or without sprinklers (NS).

Allowable Heights and Areas

• The maximum stories allowed:
  • Construction type five then an assembly you can have Maximum of 3 stories.

Procedure

1. Determine the Occupancy (Chapter 3).
2. Check Specific Provisions (Chapter 4).
3. Determine Height and Width Requirements, selecting a Construction Type (Chapter 5).
4. Assess Fire Rating and Combustibility Requirements (Chapter 6).

Structural Design Considerations

• In addition to doing steps above, you have to consult what your clear spans are like.
• Clear spans.
• Economic considerations.

Architect vs. Structural Engineer Responsibilities

• A lot of these steps are the architect's responsibilities.
• However, an architect must have some idea of what those steps are to save money on structural design.

Lateral Environmental Implications

Seismic Loads

• Factors:
  • Building mass, stiffness, and ductility.
  • Use of the building.
  • Geography (proximity to fault lines).
  • Soil quality.
  • Risk category.
• Switching building materials affects stiffness, ductility, and mass.

Wind Loads

• Factors:
  • Regional wind velocity.
  • Risk category.
  • Exposure (surrounding buildings).
  • Building height.
  • Site elevation.
  • Site topography.
  • Building enclosure.

Case Studies

Single Family Residential Building (Two Story)

• Low area, low height, short spans, walls can be used.
• Occupancy Type: Residential.
• Construction Type: Type five.
• Gravity System: Light framed wood (dimensional lumber).
• Lateral System: Stick built shear walls.
• Foundation System: Shallow strip footings.

One to Two Story Commercial Building

• Low area, low height, discrete spaces.
• Occupancy Type: Business/Mercantile.
• Construction Type: Type five.
• Gravity System: Light frame wood.
• Lateral System: Stick framed shear walls.
• Foundation System: Shallow strip footings.

Restoration of Existing Building (Six Stories)

• Built in the 1940s.

• Masonry Bearing Walls.

• The building should be 4 stories

• 25-foot column spans.

• Flexible options for partitions.

• Office space.

• Heavy Timber Frame with exterior masonry bearing walls.

• Exposed heavy timber frame on the interior that will block access to fire.

  • Interior heavy timber frame exposed.
    *What construction Type is it? - Type three
    *Does this all work with type three A or B? - B

Updated State

• Original - Factory
• New - Business
• This works for a restoration process because the loads we will apply will be equal to or lesser than.