Zoning

fx1.1 zoning – site analysis
px1.32 zoning – project feasibility

Zoning refers to the local regulations that govern land use, permitted types of development, and the construction of buildings. These jurisdictional regulations govern land use and its impact on the surrounding community, including factors such as building use, size, height, and placement on the land, as well as setbacks, because all relate to the property’s classification. These regulations also govern historic preservation rules and neighborhood conservation restrictions. They help determine whether the project location aligns with the client’s needs and is feasible for its intended use.

According to the International Zoning Code (IZC, part of the ICC family of codes), zoning deals with the “minimum requirements to provide a reasonable level of health, safety, property protection and welfare by controlling design, location, use or occupancy of all buildings and structures through the regulated and orderly development of land and land uses” within a jurisdiction.

The key difference between zoning and building regulations is that zoning relates to land use, such as commercial, residential, mixed-use, multifamily residential, industrial, or agricultural.

Building codes, on the other hand, regulate the use of the building itself, for example, the occupancy classification, such as business, assembly, or mercantile.

Many elements are necessary to determine how these codes should apply to a project, considering program needs and site or zoning constraints, such as:

• What specific zoning classifications are relevant in different jurisdictions?

• How do zoning regulation changes affect existing properties and their uses?

• What steps are needed if a project does not conform to current zoning regulations?

While zoning regulations may not always impact interior projects, they are vital components of the site context that should be documented early on when discussing the project goals with clients.

Understanding the differences among a structure’s zoning, use, and occupancy classifications is crucial to your professional expertise. This knowledge helps you assess whether these factors directly influence occupancy groups or load calculations.

Building Location

fx1.1 building location – site analysis

The location of a building and its surrounding environment are among the most crucial factors that influence its overall design and functionality. It is vital to thoroughly assess and address location-related issues, particularly those related to building codes and the authority having jurisdiction (AHJ). A property’s geographic location—whether urban, suburban, or rural—plays a significant role in determining the specific building codes and regulations that govern the project.

This includes zoning laws, land use regulations, and safety codes, which can vary significantly from one municipality to another. Understanding these regulations can help prevent costly revisions and delays later in the project.

Furthermore, the internal layout and placement of spaces within the building also affect compliance with building codes. For example, the International Building Code (IBC) outlines distinct requirements based on a building’s floor level. The ground floor may have different safety and accessibility standards than below-grade areas, such as basements and upper-level floors. These differences can include egress requirements (IBC Chapter 10), ventilation standards (IBC Chapter 12), and load-bearing considerations (IBC Chapter 5).

By carefully analyzing the external and internal location factors at the outset, architects and builders can create designs that meet regulatory standards and enhance the building’s usability and safety.

Building Types

fx1.1 building types – site analysis
px1.32 building types – project feasibility

A crucial aspect of starting any project is calculating the required space. By completing the programming and identifying space requirements, we can determine the required area for each function. The total of these individual spaces is known as the net area or program area.

Efficiency Factors

The next step is to calculate the additional space required for partitions, columns, circulation, and other areas not specific to the program. During the early planning stages, we estimate the total space needed using efficiency factors. These factors represent the proportion of usable space in a building type relative to its total square footage. They take into account the project and building type (such as commercial offices, museums, dormitories, etc.), as well as wellness or sustainability goals, which often necessitate additional square footage for specialized spaces or mechanical, electrical, and plumbing (MEP) areas. This process enables the design team to more accurately estimate the total area required, tailored to the specific project and building type.

A higher efficiency factor indicates a more efficient use of space. Efficiencies can be assessed by building type; for example, an open warehouse typically has less wasted space and is therefore more efficient, while an office tends to have more walls, circulation areas, mechanical space, restrooms, and non-programmed areas.

Net-to-Gross Ratio

This ratio of usable space to total space is often called the net-to-gross ratio. The net-to-gross ratio affects the overall spatial quality, usability, aesthetics, and, ultimately, the building’s cost.

By analyzing the relationships between building type and these efficiency factors, designers can make informed decisions regarding both the proposed building and its location.

Typical Building Types (Commercial, Residential)Efficiency Factors (Divide by this to estimate gross area for initial planning)Office0.75–0.80Retail0.75Bank0.70Restaurant, table service0.66–0.70Bars, nightclubs0.70–0.77Hotel0.62–0.70Public Library0.77–0.80Museum0.83Theater0.60–0.77School, classroom0.60–0.66Apartment0.66–0.80Hospital0.54–0.66

The simplest way to estimate the total area needed for a space is by dividing the net area by the efficiency factor.

Net Square Feet = Gross Square Feet
Efficiency

(Net SF / efficiency) = Gross Square Feet

If a program requires ten offices, each measuring 100 square feet, the total net area needed is 1,000 square feet. However, accounting for an efficiency factor of 75% (or 0.75), you will need to calculate the total space required as follows:

1,000 square feet divided by 0.75 equals approximately 1,333 square feet of space.

You can also determine the required gross area by multiplying the net area by the inverse of the efficiency factor. In this case, the inverse (1 divided by 75, or 1/.75) is 1.33, also known as the grossing factor. Multiplying the grossing factor by the net area (1.33 x 1,000) again yields approximately 1,333 square feet, which aligns closely with the previous estimate.

Change of Use

fx1.1 change of use – site analysis

In addition to zoning, location, and general building type, a designer will identify the building’s general use and occupancy group and review the requirements in International Building Code Chapter 3, Occupancy Classification and Use, to determine how the proposed use aligns with the project’s goals.

A change of use happens when the way a building is occupied changes or the building is used for a different purpose, which may lead to new code requirements for that location. It is also essential to consider how the building’s spaces will be used now and in the future. For example, if a space is used temporarily as an open office but will later be a training room, it may need to meet both Assembly and Business code requirements. This ensures the design meets the strictest rules. Significant renovations may be needed when the use changes if these requirements are not addressed.

Change of Use to a Different Occupancy Classification

For instance, consider a former craftsman bungalow situated on a bustling retail street. If this residence is transformed into a lively bakery with on-site cooking facilities, it represents a definitive change in use. This transformation alters the building’s functional purpose and necessitates reclassification, as it no longer serves its original primary function as a residence.

Change of Use Within the Same Occupancy Classification

Alternatively, a scenario may arise in which the change in occupancy remains within the same classification but involves a different level of use. For example, consider opening a new restaurant that increases its seating capacity, which may trigger a change from Business to Assembly occupancy, or a childcare center that serves more children, which may change from a Residential to an Educational or Institutional occupancy.

While both examples fall within a similar hazard level of occupancy, they represent distinct functional uses and different numbers of occupants, warranting a change in use. Refer to IBC Chapters 3 and 10 for detailed guidance in both scenarios.

The applicable building codes under the Authority Having Jurisdiction (AHJ) will provide essential guidance to ensure the site is suitable for the proposed new use. Most importantly, it is imperative to verify that the building will comply with all safety requirements to protect public welfare, as a change in use often triggers changes to the number and location of exits.

Environmental Impacts

fx1.1 environmental impacts (e.g., seismic, air quality, extreme weather, sound) – site analysis

In addition to the code-regulated aspects of a building’s location, an assessment should also address the site’s physical context and exterior spaces.

Seismic

Seismic refers to the nature of or caused by an earthquake or vibration of the earth, whether due to natural or artificial causes.

Seismic forces are essential for interior designers to understand. During the existing conditions analysis, identify any seismic constraints at the project location. Identify them for use as you develop the project.

Many locations have seismic requirements in areas not known for earthquakes. The International Building Code (IBC) and other model codes divide the United States into different zones. Each zone represents the potential severity of the seismic activity. The interior designer is typically not required to provide special detailing in the least severe zones. In high-risk areas, the designer must research the requirements for the project location and consult a licensed structural engineer.

Section 1613 of IBC 2018 addresses seismic loads, including an updated map of seismic regions. Beyond the Western US, there are seismic hotspots in Oklahoma, the mid-Mississippi River Valley near the Ohio River, the mid-coastal South Carolina, and the Northeast, including Boston. The Natural Resources of Canada seismic map also illustrates hazardous seismic areas in the Provinces and Territories.

Per CIDQ’s definition, “Interior design encompasses the analysis, planning, design, documentation , and management of interior non-structural / non-seismic construction and alteration projects in compliance with applicable building design and construction, fire, life-safety, and energy codes, standards, regulations, and guidelines for the purpose of obtaining a building permit, as allowed by law.”

Interior Designers do not design or change seismic or structural elements in a building. However, they should have a basic working knowledge of building structures and be able to read architects’ and engineers’ plans to make informed decisions.

For example, interior construction elements that may need to resist earthquake forces include:

• Partitions tied to the ceiling

• Partitions over a specific height

• Suspended ceilings

• HVAC ductwork

• Light fixtures

• Sprinkler and other piping

• Bookcases and storage cabinets

• Laboratory equipment

• Wall-mounted items

• Access floors

Air quality

The role of the interior designer extends beyond aesthetics; it encompasses the critical responsibility of ensuring high indoor air quality (IAQ). This is essential for promoting the health and well-being of occupants and for reducing absenteeism in work and living environments.

A related concept, indoor environmental quality (IEQ), encompasses the various elements that contribute to an indoor space’s overall health. IEQ includes air quality, access to natural daylight, views of the outdoors, pleasant acoustic conditions, occupant control over lighting, and thermal comfort. These components work in synergy to create a nurturing indoor environment that supports physical and mental health.

From an air quality perspective, two crucial aspects exist that designers must thoroughly understand:

1. Indoor Air Quality (IAQ) refers to the air quality within buildings, particularly its effect on the health and comfort of occupants.

2. General Air Quality entails introducing fresh outdoor air into indoor spaces, which is essential for diluting indoor pollutants.

Maintaining good indoor air quality is not just a design choice but a necessity for fostering healthy indoor environments that contribute to heightened productivity, creativity, and motivation among occupants. Poor indoor air quality can lead to many health issues, negatively impact users’ well-being, increase absenteeism, and depress overall satisfaction with living or working conditions.

During a comprehensive site analysis, the interior designer should collaborate with mechanical engineers and other consultants to assess and document potential factors that could degrade air quality. It’s crucial that designers not only identify these issues but also actively implement thoughtful design strategies that promote healthy indoor air quality. By prioritizing IAQ and overall indoor environmental quality, designers can significantly enhance the livability and functionality of interior spaces, ultimately leading to a more productive, creative, and satisfied occupant population.

Causes of poor indoor air quality

1. Contaminants from indoor sources. These include tobacco smoke, formaldehyde, off-gassing from building materials, and VOCs from interior materials and finishes.

2. Contaminants from outdoor sources may be introduced when venting or windows are improperly located. For example, windows near parking garages may pull in exhaust, and wildfire smoke may contain harmful particulates, carbon monoxide, carbon dioxide above recommended levels, and other contaminants.

3. Biological contaminants in the project environment include mold, mildew, bacteria, mites, pollen, and animal dander.

4. Poor ventilation or inadequate supply of fresh air, in which pollutants are not diluted or flushed out. For example, a study by the US Centers for Disease Control and Prevention (CDC) found that nine people in Wuhan, China, were infected with COVID-19 by sitting near an air conditioning vent in a restaurant.

Symptoms of poor indoor air quality

1. Sick building syndrome. If health symptoms can’t be traced to a particular source, but disappear after the occupant leaves the building.

2. Building-related illness occurs when health symptoms are associated with a specific building contaminant. In this case, symptoms persist after leaving the building, unlike those associated with Legionnaires’ disease, which is caused by bacteria in a building’s plumbing.

3. Multiple chemical sensitivity is caused by exposure to chemical contaminants. Long-term sensitivity may recur and intensify with each exposure.

Concerns regarding off-gassing and particulate matter, such as asbestos, from existing hazardous materials are significant. If asbestos is detected during the site analysis, the designer should immediately alert the client and recommend that they hire a certified asbestos abatement contractor to remediate the site before any further work is undertaken.

Interior designers have limited control over air quality because there are no federal standards for indoor air quality, and state or provincial regulations can vary widely across jurisdictions. This makes it challenging for designers and their consultants to assess potential contaminants and determine the most effective strategies for addressing them in the future. Designers can control off-gassing by selecting finishes with low or no VOCs and allowing furniture and materials to off-gas before installation.

Typically, air quality is managed by the building architect or mechanical engineers, with input from the building owner. The strategies that interior designers can implement can be categorized into broad groups:

• Eliminate or reduce the sources of pollution

• Control building, including indoor temperature and humidity

• Establish good maintenance procedures

• Control occupant activity as it affects IAQ

Be familiar with environmental regulations that impact the interior environment beyond building codes.

US codes/standards that address air quality:

40 CFR 50: National Ambient Air Quality Standards, 2013. U.S. Government Printing Office, Washington, DC.

ANSI/ASHRAE Standard 62.1: Ventilation for Acceptable Indoor Air Quality, 2019. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Atlanta, GA.

ANSI/ASHRAE Standard 62.2: Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings, 2010. American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Atlanta, GA.

AQMD Rule 1113: Architectural Coatings, 2011. South Coast Air Quality Management District, Diamond Bar, CA.

AQMD Rule 1168: Adhesive and Sealant Applications, 2005. South Coast Air Quality Management District, Diamond Bar, CA.

NAAQS: National Ambient Air Quality Standards, 2009. U.S. Environmental Protection Agency, Washington, DC.

Canadian standards for health risks of indoor air contaminants:
Indoor air quality resources for professionals
Indoor Air Quality – Legislation

Extreme Weather

Interior designers involved in commercial and residential projects, from the site analysis phase onwards, must now learn to address extreme weather events caused by climate change. These events affect how they assist clients in choosing suitable locations and situations. These designers—and the project solutions they develop—must understand the concept of “resiliency.” Selecting a project site that can withstand extreme weather events helps protect the users and inhabitants of these spaces during prolonged emergency conditions while safeguarding the facility’s investment.

This includes understanding transportation options to and from the project site, developing off-grid energy sources, and specifying and coordinating electrical and HVAC solutions in collaboration with other building professionals.

For example, houses on stilts are more likely to survive flooding in coastal areas, floodplains, and low-lying regions than houses built on the ground. Both exterior and interior fire-resistant materials help a structure withstand a catastrophic fire, particularly in urban environments.

Sound (or Noise?)

An essential aspect of site analysis for any project, whether it involves a new build or modifications to an existing residential or commercial space, is the observation, analysis, and documentation of acoustics and sound sources.

Identifying noise sources is crucial for conducting a thorough site analysis. Observing ambient noise from transportation, industry, public spaces, and other loud sources can inform design choices regarding building layouts, massing, materials, and acoustic treatment.

Acoustics significantly influence the overall quality of interior design. Spaces that are overly noisy or reverberant can be distracting at best and unusable at worst. Loud sounds can damage our hearing over time. Conversely, auditoriums or classrooms where sounds are hard to hear are also unsuitable. We struggle to hear significantly less intense sounds than the background noise.

The distinction between sound and noise is subjective and context-dependent, making it essential for project success. So, what exactly is “sound”? While noise refers specifically to unwanted sound, sound encompasses all auditory experiences we perceive. What one person finds pleasant, another may deem noise. Sound can originate externally, from traffic, or internally, like mechanical equipment. It may come from a nearby break room or noise from aircraft flying overhead in a residential area. Sound can enhance a space’s functionality, whereas noise can be disruptive.

Just as sound can improve performance within a space, noise can hinder it; for example, music can be enjoyable for one person but annoying to another. Appropriate sounds in offices, retail spaces, or public areas, such as restaurants or cafes, convey a sense of activity that contributes to the environment’s success. Enhancing and controlling sound enriches environments and fosters communication, while noise often leads to frustration and requires management through various methods. Evidence-based design has documented how unwanted sounds can adversely affect hospital patient recovery and disrupt delicate research.

Noise and other interruptions in office settings can make it difficult for employees to concentrate. It typically takes about 20 minutes for individuals to enter a productive flow state, and any distracting noise can significantly impede that flow. On average, workplace interruptions occur approximately every seven minutes.

On the other hand, an office space can be too quiet, making every rustle or cough feel intrusive without low-level ambient background noise to absorb them. While some employees find noise distracting, those who are sensitive or prone to distraction may feel profoundly disabled by it.

With growing awareness of how sound impacts neurodivergent individuals, the need for thorough site condition analysis has become increasingly critical. When an interior designer plans a new project from the ground up or modifies an existing structure, addressing sound issues should be prioritized early in the planning stages. Failing to address noise concerns and implement necessary mitigation strategies later in the project timeline can lead to construction delays, unexpected costs, and design conflicts.

How Designers Can Control Sound

Interior designers can use several strategies to reduce sound within and between spaces.

Interior designers can enhance a room’s acoustic quality through effective space planning, such as grouping collaborative and quiet zones, and effectively separating and reducing the loudness between the sound source and other spaces.

Thoughtful wall and ceiling designs, along with the selection of appropriate finishes, also control sound relative to the space’s intended purpose, absorbing sound and enhancing sound quality. Hard surfaces and parallel walls can intensify noise.

White background sound can often mitigate noisy conversations and some mechanical systems without reducing air intake, although newer equipment is usually quieter. However, reducing the sound source level is not always possible when the sound is generated by a fixed piece of machinery, people, or similar sources. However, if the source is noise from the outside or an adjacent room, the transmission loss of the enclosing walls can be improved, reducing sound transfer between spaces. Sometimes, a noise source can be enclosed or modified to reduce its sound output, such as fire-retardant acoustic panels and mass-loaded vinyl (MLV) to enclose and reduce the sounds of elevator equipment.

Solar orientation

fx1.1 solar orientation – site analysis

Identifying a building’s solar orientation and immediate surroundings is a critical aspect of site analysis that plays a significant role in sustainable architecture. Understanding the project location’s specific latitude—how far north or south it is—provides essential insights into the solar path and its seasonal variations. This knowledge informs design decisions and influences the structure’s energy efficiency and temperature regulation.

While solar orientation and desirable views are sometimes overlooked in the design process, they can enhance both the aesthetic appeal and functional performance of nonresidential buildings when appropriately integrated. For example, strategically placed windows can maximize natural light while minimizing glare. Designers often employ bubble diagrams, drawing sun symbols to indicate solar exposure patterns during the planning phase. These symbols can be labeled with specific descriptors such as “low, hot west sun” or “high, south sun” to communicate the intensity and angle of sunlight at different times of day and seasons. These serve as reminders of how solar aspects can influence various design choices.

In addition to aesthetic considerations, understanding solar orientation is vital for managing heat gain, particularly from direct sunlight on southern exposures. This advantage can benefit colder climates, such as Calgary in January, where maximizing solar gain can help offset heating costs. Conversely, this same direct sunlight can lead to excessive heat buildup in hotter climates, such as Arizona, substantially burdening HVAC systems year-round.

Moreover, direct sunlight exposure can significantly impact the materials used in construction. For instance, selecting materials that resist fading and maintain colorfastness is crucial in areas with intense sunlight, as prolonged exposure can cause deterioration over time. Additionally, considering solar orientation can enhance daylighting concepts, creating a more inviting and energy-efficient environment while supporting sustainable design principles.

A comprehensive understanding of solar orientation and related factors is imperative for effective architectural and interior design. This ensures that buildings not only look good but also function well throughout the year, adapting to the specific climatic conditions of their locations.

Views

fx1.1 views – site analysis

Views are an essential consideration in both residential and commercial interior design. A careful site analysis during programming can reveal external and internal site views.

Designers should seek opportunities to utilize desirable views. Undesirable views can be modified or hidden with window coverings or other design solutions. Areas with undesirable views can also be utilized for rooms where a view is not a priority.

In commercial construction, the spaces on exterior walls must be determined early on. Designers can set guidelines for such decisions during the programming phase. For example, offices with windows are often a sign of status or hierarchy in an organization.

The company’s brand and culture, as well as the desire to portray them in the physical space, also impact how designers address views. In other cases, windows in standard and open work areas increase daylighting, allowing everyone to benefit.

Criteria related to privacy or security may require limiting access to or from specific spaces. These should also be identified and documented during the programming phase.

Transportation

fx1.1 transportation – site analysis

Documenting how occupants arrive at that location is also essential during the programming phase, as it affects issues of resiliency and sustainability.

For example, how will employees get to work if the project site is located in an urban area? Is it close to public transportation? Is there adequate parking for employees and guests? If the site is suburban, the same issues apply, but in a different way. An office site location without public transportation may not work for employees who don’t own cars, and a lack of available transportation would be detrimental to the project’s success.

Accessibility and the ADA may also affect transportation to the project site. Can the location provide adequate space for shared mobility van drop-off and pick-up? The designer should document parking availability and public transportation access for employees with mobility challenges.

Designers must understand how space users and guests may arrive at the project. This extends beyond sustainability issues that can impact any LEED or WELL certification.

Other considerations could include:

• providing bike storage rooms

• extra-large closets or at-desk storage space for coats, boots, and backpacks

• changing facilities for commuters who cycle to work or use other alternative transportation

• appropriate guest arrival services, including ease of parking

Site Conditions and Constraints

fx1.1 site conditions and constraints – site analysis

The site’s qualities can make achieving the client’s goals easier or more difficult. The designer must research and document the specific architectural or code constraints and opportunities. These are the types of questions a designer may seek to answer:

• Is there enough space within the building to locate the proposed new office?

• How will the shape of the building affect the efficiency of space planning? For example, how much extra space may be needed for a building with a curved or angled footprint?

• Is a structural column in a location interfering with the planned function or views?

• Is access to utilities workable for the space? For example, does the location of plumbing stacks limit the placement of required fixtures?

• Will local building codes permit the necessary modifications?

The designer needs answers to these questions to create realistic projections for new or renovated spaces.

Historical information

fx1.1 historical information – site analysis

Historical information on a project site is used throughout the design process, beginning with the site analysis phase. Understanding a building’s history is helpful when researching code, as it involves addressing issues such as changes in use and accessibility updates.

These affect what and how you can proceed with the project design and successful solution:

• Defining and documenting the existing classification of the building with the AHJ

• Determining if there are special variances or other site considerations

• Documenting the age and history of building services and systems

• Determining if the building or space has a historical designation