The Architect's Studio Companion

1. Codes and Zoning: The Foundation of Design

A designer works under complex legal constraints that exert a powerful influence on the form a building may take.

Legal Framework. Design is not just about aesthetics; it's deeply intertwined with legal requirements. Zoning ordinances dictate land use, building heights, and parking, while building codes regulate safety, materials, and structural integrity. These regulations, often local or state-specific, are the invisible hand shaping architectural possibilities.

Model Codes. While local codes vary, most North American building codes are based on model codes like the International Building Code (IBC) in the US and the National Building Code of Canada (NBCC). These model codes provide a standardized framework, allowing for some generalization in preliminary design.

Preliminary Guidance. This book focuses on the IBC and NBCC, offering simplified guidelines for incorporating code requirements into early design stages. However, it's crucial to consult local regulations and verify that the information used accurately reflects the specific requirements of your project.

2. Structural System Selection: Balancing Needs and Constraints

When choosing a structural system for a building, you must first determine the range of structural systems that the relevant building code allows.

Code Compliance First. The selection of a structural system is not solely based on design preferences; it must align with the relevant building code. This involves identifying the Occupancy Group of the building and then consulting code tables to determine permissible Construction Types.

Design Criteria. Beyond code compliance, structural system selection is influenced by various design criteria, including:

• Irregular forms: Sitecast concrete, light gauge steel, platform frame
• Fire resistance: Concrete, heavy timber, mill construction
• Column placement flexibility: Concrete flat plate, metal space frame
• Minimal floor thickness: Prestressed concrete, post-tensioned slabs
• Long spans: Heavy wood trusses, steel frames, precast concrete tees
• Construction speed: Steel, wood, precast concrete
• Foundation stability: Steel frame with bolted connections, heavy timber frame

Practical Span Ranges. Different structural systems have practical span ranges. Wood joists are suitable for short spans, while steel trusses and concrete systems are better for longer spans. The choice depends on the building's intended use and spatial requirements.

3. Configuring the Structure: Stability and Spatial Harmony

The arrangement of shear walls, diagonal braces, or rigid joints in a structure is crucial to their effectiveness in resisting lateral forces acting on the building.

Lateral Stability. Buildings must resist lateral forces like wind and earthquakes. This is achieved through shear walls, braced frames, or rigid frames. The choice and arrangement of these elements significantly impact the building's form and interior space.

Balanced Arrangements. Stabilizing elements should be arranged symmetrically in relation to the building's mass to avoid unbalanced forces. These elements can be placed within the interior or at the perimeter, but must resist lateral forces from all directions.

System-Specific Methods. Different structural systems have different methods of resisting lateral forces. Wood and masonry systems often rely on shear walls, while steel and concrete systems can utilize rigid frames or braced frames. The choice of system influences the configuration of stabilizing elements.

4. Sizing Structural Elements: Practical Approximations

This section will assist you in assigning approximate sizes to structural elements.

Wood Systems. Wood construction includes platform framing and heavy timber. Sizing charts provide guidance on column, stud, joist, rafter, beam, and truss dimensions. Fire-resistance ratings are also considered.

Masonry Systems. Masonry construction includes brick and concrete block. Sizing charts provide guidance on column, wall, lintel, and arch dimensions. Fire-resistance ratings are also considered.

Steel Systems. Steel construction includes hot-rolled and cold-formed members. Sizing charts provide guidance on stud, joist, column, beam, girder, and truss dimensions. Fire-resistance ratings are also considered.

Concrete Systems. Concrete construction includes sitecast and precast systems. Sizing charts provide guidance on column, wall, beam, girder, slab, joist, and tee dimensions. Fire-resistance ratings are also considered.

5. Mechanical and Electrical Systems: Integrating Function and Space

This section will help you select a heating and cooling system for the preliminary design of a large building.

System Selection. The choice of mechanical and electrical systems depends on factors like building size, occupancy, climate, and budget. Central systems are more efficient for large buildings, while local systems are suitable for smaller ones.

Large Building Systems. Central systems include all-air, air-water, and all-water systems. All-air systems offer better air quality control, while all-water systems are more compact. Specific systems include:

• Variable Air Volume (VAV)
• Constant Air Volume (CAV)
• Air-Water Induction
• Fan-Coil Terminals
• Closed-Loop Heat Pumps
• Hydronic Convectors

Small Building Systems. Small buildings often use simpler systems like forced air, hydronic heating, electric baseboard, or packaged terminal units. Passive solar heating and evaporative cooling are also options.

Space Planning. Mechanical and electrical systems require dedicated spaces for equipment, ductwork, and piping. These spaces must be planned carefully to minimize their impact on usable areas and to ensure easy access for maintenance.

6. Daylighting: Harnessing Natural Illumination

Daylighting is the use of natural light to illuminate the interior of a building.

Benefits of Daylighting. Daylighting offers numerous benefits, including energy savings, improved visual comfort, and a connection to the outdoors. However, it requires careful design to avoid glare and excessive heat gain.

Sky Cover and Sun Path. The amount of available daylight varies with sky cover and the sun's path. Buildings in clear sky areas require more control of direct sunlight, while buildings in overcast areas benefit from larger daylight openings.

Building Design. Daylighting is most effective in buildings with narrow or elongated plans, south-facing windows, and high ceilings. Interior elements should be arranged to minimize obstructions to daylight.

Sidelighting and Toplighting. Sidelighting uses windows and clerestories, while toplighting uses skylights and roof monitors. Sidelighting is most effective near the perimeter, while toplighting can illuminate deeper areas.

7. Egress Design: Ensuring Safe Evacuation

The function of a building egress system is to conduct the occupants of the building to a safe place in case of a fire or other emergency.

Egress Components. An egress system consists of three components: the exit access (path to an exit), the exit (protected way of travel), and the exit discharge (path to a public way). Each component must be designed to meet code requirements.

Exit Separation. Buildings must have at least two separate exits, located as far apart as possible. Dead-end corridors should be avoided, and travel distances to exits must be within code limits.

Stairways and Ramps. Exit stairways must be enclosed in fire-resistant walls and doors. Ramps must have a maximum slope and require landings at specific intervals.

Accessible Egress. Buildings must provide accessible means of egress for disabled persons, including accessible routes, ramps, elevators, and areas of refuge.

8. Height and Area Limitations: Navigating Code Restrictions

All building codes place limitations on building heights and areas in relation to the type of construction employed and the use or uses to which the building will be put.

Code-Defined Limits. Building codes limit building heights and areas based on Construction Type and Occupancy Group. These limitations are designed to ensure fire safety and are presented in simplified tables for both the IBC and NBCC.

Construction Types. Construction Types are defined by the fire-resistance ratings of structural elements. The tables provide height and area limitations for various Construction Types, including 3-Hour, 2-Hour, 1-Hour, Unprotected, Mill, and Wood Light Frame.

Mixed-Use Buildings. Mixed-use buildings require careful consideration of code requirements. Nonseparated uses are governed by the most restrictive occupancy, while separated uses are divided by fire separations.

Exceptions and Adjustments. The codes allow for adjustments to height and area limitations based on factors like sprinkler systems, street frontage, and the presence of fire walls. These adjustments are incorporated into the tables.

Last updated: January 19, 2025