PPP Notes - Zoning Ordinances

(These notes are compiled from Spreiregen's ARE Exam Review)

CHAPTER ELEVEN - ZONING ORDINANCES AND BUILDING CODES

INTRODUCTION

Zoning ordinances, building codes, and all other statutory restrictions that apply to a site or a structure must be identified and understood in the earliest design stages of a project.  There restrictions may have significant effects on a project's feasibility, and at times they may be major determinants of form.  Legal constraints on site use can also affect the program of a project.  A particular deed restriction, for example, might have a critical and wholly unanticipated effect on how a project is permitted to function.

ZONING

Human societies have alway regulated the use of land in order to serve the interests of society as a whole.  The various European colonial powers, which settled what was to become the United States, all exercised various forms of land use control and, in some cases, regulated building construction.  The Spanish "Law of the Indies" was the most elaborate colonial system of regulation, instituted shortly after Columbus's discovery and continuing in effect through the Spanish settlement of California.

The predominant system of American land use and building regulation is zoning.  It was the product of late 19th and early 20th century growth of American cities, in which the stability of development, particularly long-term investment required protection.

The principal purpose of zoning is the protection of property rights.  The first modern system of zoning was introduced in the United States in 1916 in New York City, where hitherto unregulated construction of tall buildings had created a perceived threat to property values.  The 40-story Equitable Building cut off light and air from neighboring properties and thus threatened to undermine their value.  This focused attention on the problem of overcrowding and overdevelopment.  Zoning ordinances were adopted under the rationale of protecting the public's right of access to adequate light and air.  In fact it was a building's access to light and air that was being protected.

The concept of zoning was legally validated in a landmark Supreme Court case, Euclid vs. Ambler, in 1925.  Euclid was a suburb of Cleveland that adopted zoning ordinances of a kind which have since become typical.  Here again the underlying rationale was the protection of public health, welfare, and safety.  Land use districts, lot sizes and setbacks, and billboard restrictions were prescribed.  In the 1920s such zoning ordinances were adopted by numerous municipalities throughout the country.  The better residential suburbs, privately developed, had been protected through their use of covenants, which were used mostly for residential developments of fairly large scale.

Zoning was used for all types of land development: commercial, industrial, residential, institutional, etc.  In comparison with covenants, zoning was less stringent in its requirements for residential development.  Lots were often narrow, and side yards, and the separation between buildings, minimal.

Once established, zoning regulation became more complex, as provisions of a social and environmental nature were added.  A landmark illustration was the Supreme Court case of Berman v. Parker, in 1954.  In this case, the Court established aesthetics as a proper subject of public concern.  The subject under consideration was an urban renewal project.  The court ruled that "it was within the power of the legislation to determine that the community should be beautiful as well as healthy, spacious as well as clean, well-balanced as well as carefully patrolled."

Social, economic, and political events thus combined to establish systems of this began with the Depression of the 1930s.  The government decided that one of the keys to economic recovery was the stimulation of the home building industry.  This led to home loans guaranteed by the federal government.  This, in turn, required that the housing thus built had to meet certain standards of land se and construction.  So began the pervasive system of uniform standards of construction, the benefit of which was the safeguarding of investment funds and the improvement of quality, the disadvantage of which has been stultifying uniformity.

Public control through planning and construction regulations is now firmly established.  The determination of applicable controls is a first step in the development of any piece of property.  Starting with either the deed or similar documents pertaining to land ownership and use, and proceeding to municipal and even federal regulation, the most common types of controls and regulations will be discussed next.

ZONING IN OPERATION

The buyer of a parcel of land must determine what he is allowed to do on his land, identifying possible deed restrictions but, more importantly, restrictions imposed by zoning.  This is done by examining the applicable zoning ordinances in the specific area in which the property is located.

Land zoning is the division of the land of a city, county or other jurisdiction, into districts, or zones, and the allocation of different uses to these different zones.  The primary purpose of zoning, as described earlier, is the protection of property values, and with that, investment stability.  In support of that purpose zoning exercises the following restrictions:

1. REGULATION OF THE USE AND INTENSITY OF USE OF A PARTICULAR PARCEL OF LAND

A residentially zoned lot, for example, may only have a house built upon it.  The house may have a maximum size, and there may be requirements related to lot coverage, setbacks, and height.

2. PROTECTION AGAINST DISCORDANT NUISANCES

Such as factories or commercial buildings.

3. PROTECTION AGAINST UNDESIRABLE BUSINESSES

Bars, poolrooms, and adult bookstores may be prohibited in certain areas.

4. PROTECTION AGAINST DANGER

Hazardous industries, such as factories using explosive or toxic substances, may be prohibited from areas with dense populations.

5. PROTECTION OF LIGHT, AIR, AND OPEN SPACE.

Buildings are often regulated in accordance with the size of the lot they are to occupy.

Early zoning ordinances recognized three basic land uses: residential, commercial, and industrial.  Within these broad categories, many sub-classifications have developed.  Residential districts may be divided into single-family districts and multiple-family districts.  Multiple family zones may be divided into walk-up and high-rise.  Commercial zones may be divided into retail and wholesale.  Industrial zones may be designed as light or heavy manufacturing areas, etc.

The various uses defined in a zoning ordinance are usually ranked on a scale of priority, starting with single-family dwellings.  Multiple-family dwellings usually rank lower on the list, with commercial and industrial uses ranking lower still.  A piece of land in a particular zoning district may be used for the uses designated for that zone and usually for any use ranked above it, but not for a use ranked below it.  For example, a single-family residence could theoretically be built in any zone, although economic and other considerations would probably make that unfeasible.

Zoning also regulates the size and location of a building on its site.  Examples include required setbacks from the property lines, limits on maximum percentage coverage of the lot area, limits on the number of dwellings per acre, and off-street parking requirements as a ratio of cars to building floor area.

A zoning ordinance must provide for so-called nonconforming uses; that is, uses that do not comply with current zoning regulations, but that were permitted by the zoning ordinances in effect when the structure was built.  In permitting a nonconforming use, zoning ordinances permit minor or nonstructural alterations.  Unless the building is also brought into conformance with current zoning regulations.  If the owner abandons the nonconforming use for a certain period of time, often three years, he may lose the right to exercise the nonconforming use.  If a nonconforming building is razed or destroyed by fire, rebuilding must be in compliance with existing zoning standards.

A conditional use is a use that is permitted by a zoning authority with certain restrictions attached, when the proposed use is not normally permitted in that location.  A conditional use may be granted if it is found to be in the public interest.  A school, for example, may be permitted in a residential zone, subject to such requirements as screening of playground noise and providing parking spaces.  Such uses as airports, cemeteries, landfill projects, and public utility installations may be difficult to locate because local zoning ordinances make no provision for them.  Under such circumstances, a zoning authority, working with other public authorities, may grant a conditional use for a site, subject to restrictions to protect the interests of nearby property owners.

Zoning ordinances may place unintended burdens on particular parcels of land, or make it difficult to develop a particular parcel.  For that reason municipalities refer requests for a variance to a zoning board of review.  In theory, a variance is granted only where exact and literal application of the ordinance would cause undue hardship or practical difficulties.  For example, where a zoning ordinance requires a 60-foot frontage on residential lots, an irregular lot may have only 55 feet of frontage, but is otherwise in conformance.  The zoning board would very likely grant a variance for the reduced frontage to the owner so that he could build on the property.

A variance or conditional use does not change the basic zoning.  A change in zoning is not easily accomplished.  An owner seeking to bring about a change in zoning must institute a hearing procedure.  He first submits a petition to the zoning board requesting a change.  After this a notice is published in a local newspaper announcing a public hearing on the change.  At the hearing, those favoring and opposing the change are heard.  Finally, the board renders a decision.  This might result in a change of zoning for the entire zoning district, if that was applied for, or it might result in a change of zoning for a specific parcel, if that was applied for.  This is referred to as spot zoning.  Spot zoning may be used to alleviate economic hardships that would adversely affect the owner of a particular parcel.  

Zoning variances and spot zoning are obviously prone to manipulation by special interests.  Hence, judicious public administration is vital to the proper exercise of zoning regulation.

ZONING AS A DESIGN DETERMINANT

Although zoning was not originally intended to be a determinant of design, it has clearly become so.  Since zoning ordinances specify setback, height, lot coverage, floor area in relationship to lot size - even architectural character in some instances - zoning has become an important determining factor in design.

At its very best, even under well-intentioned management, zoning is an extremely crude determinant of design.  By its nature it can not operate at the level of subtlety or discernment which sensitive site and building design require.  Zoning, as a design determinant, assures uniformity at the cost of subtlety, refinement, and variety, which are the basis of sensitive architecture.  And, too often, such uniformity creates environmental sterility and monotony.  

A more suitable system is a design plan in which land use and performance specifications are established, and for which a design review procedure is utilized.  This system has long been in use in numerous European countries, and in urban renewal projects and "historic zones" in the United States.  It is, in fact, the regulatory system for the physical development of American college and university campuses.  It is also used in new town development and resort area development.

To avoid the uniformity of conventional zoning, a new type of zone, called the planned unit development (PUD) has been devised, which allows a mixture of uses not otherwise achievable in conventional zoning.  In practice, however, it is still not widely used.

Zoning is no substitute for conscientious design.  Unfortunately it has not only become a prime determinant of design, it actually prevents the highest level of design quality from being achieved.  Nevertheless, it is the regulatory system within which most building is done.

VARIANCE AND CONDITIONAL USES

A variance is a special authorization which grants an owner permission to deviate from the zoning requirements applicable to a land parcel.  It may be granted in a case where the zoning requirements create a special or personal hardship, but only after a public hearing before an administrative authority, called a Board of Adjustment or a Board of Zoning Appeals.

A conditional use differs from a variance in that it is granted by a zoning board for a special purpose, such as a school, hospital, cemetery, and other such use.

Although a variance and conditional use both permit deviation from the literal terms of the zoning code, the purpose of a variance is to avoid hardship to an individual owner, while a conditional use is for the welfare and convenience of the public.  When a zoning conditional use is sought, the advantages and disadvantages are discussed before the board, agency, or commission having authority.  The important issues of the case are debated, and the final decision is made by the zoning authority.

NONCONFORMING USE

A nonconforming use is one that is no longer permitted by the zoning ordinance.  The original development might have predated the adoption of a zoning ordinance, or it might have become nonconforming as a result of recent code revisions.  Either way, it is referred to as a nonconforming use.  Unless it is unsafe, such a use is generally allowed to continue.  And although the building cannot be expanded or altered to any great extent, ordinary maintenance and repairs can be done.

Zoning ordinances and their interpretations vary from community to community, and therefore careful checking of the applicable ordinance is required.  During site selection, a preliminary check of zoning must be made.  In subsequent stages of preliminary design, a more detailed examination of zoning requirements and other possible restrictions must be made.  In practice, zoning ordinances become modified over a period of time to suit local economic, political, geographic, and environmental conditions.  Thus, not two zoning ordinances are exactly alike, even though they may govern similar land uses.

ZONING CODE FEATURES

In the 1920s, the U.S. Department of Commerce published a standard zoning ordinance.  Since then, however, many municipalities which adopted that model have been forced to modify it to suit their own special needs.  For large municipalities, zoning ordinances have become extremely complex.  Thus, there is no uniform zoning ordinance analogous to the Uniform Building Code, simply because zoning variations are too diverse to make one code practicable.

The application of zoning ordinances results in the segregation of permitted uses, control of population density, and provisions for parking and loading spaces.  Zoning also influences building form - height, size, and setbacks - and thus, it is a determinant of form.  Zoning stabilizes property values by preventing deleterious land uses, such as a noisy factory within a residential zone.

Permitted uses are regulated by zones established on a map, which is legally a part of a zoning ordinance.  The prime intent of such maps is to segregate uses in order to prevent incompatibilities.  In some cases, however, the practice of use segregation precludes compatible activities, such as a small convenience store in a residential neighborhood.

Zoning has also been used to attempt remedies for certain social problems; for example, to maintain low population density in the questionable belief that high density causes crime.

Zoning regulates the physical design of a building through such factors as height, number of stories, total bulk of building, setbacks at front, side and rear, minimum dimensions of lot, minimum lot area, minimum floor area of dwelling units per acre, and number of off-street parking spaces.  Other matters, such as control of advertising signs, driveway access to a site, loading dock requirements, etc., may also be controlled through zoning.

Building setbacks are justified by the demand for light, air, and spaciousness.  Setbacks and height limitations may also be warranted on aesthetic grounds.  For example, limitations on height and bulk in relation to street width may be established to prevent a sense of oppressiveness.  A significant aspect of zoning designations is that they make it possible to forecast the kind and amount of utility services that an area will require in the future.  Architects should also explore "infill" design, which explores the possibility of fitting additional buildings into an area that has low density.  This sustainable design approach saves energy by designing buildings that reuse existing infrastructure (sewers, water supply lines, etc.).

Requiring setbacks of a building from the property lines is common practice in residential zones and sometimes in commercial and manufacturing zones.  The term "building line" refers to a line beyond.  In most cases, the building line is parallel to the property line and set back from it in accordance with the zoning ordinance.

In residential areas, setbacks provide increased privacy, encourage lawns and gardens for common enjoyment and general enhancement of a neighborhood, provide fire-fighting access to the sides and rear of buildings, and permit possible future street widening.  In other zones, front setbacks may provide off-street parking, or the space may exist primarily for aesthetic reasons.  Front setbacks are often related to a structure's height, which is determined by means of a formula, the effect of which is to locate tall buildings back from the street, thus providing increased open space.

To encourage openness, some zoning codes limit the bulk of a building by means of a formula which restricts the total floor area to a multiple of the lot area.  This is referred to as the floor area ratio (FAR).  In addition, the ground area covered by a structure may be limited to a specified percentage of the lot area.

Height limitations are often established in residential areas.  For single-family and duplex residences, three stories is a typical maximum, while the height of apartment buildings generally has no limitation, other than that applicable to all buildings.

Life safety is another consideration in establishing maximum building heights.  The extended length of fire-fighting ladders was, historically, the basis for limiting height.

Building heights were also restricted by a structure's ability to resist earthquakes or lateral wind forces.  Recent fire-fighting methods and modern structural engineering techniques have eliminated those earlier limitations.

Building components such as fan rooms, elevator penthouses, and skylights are usually allowed to exceed the established height limit, if they are set back from the parapet and limited in area.

The Summary of Zoning Regulations of the City of Los Angeles is reproduced on the following two pages as an example of typical zoning requirements.  As can be seen, residential building lots must normally satisfy a minimum area and a minimum width requirement.  The relative number of efficiency, one-bedroom, and two-bedroom apartment units in a project may also be regulated. 

Many cities require a minimum number of off-street parking spaces for tenants and tenants' guests.  This is related to the number of apartments in a project and, sometimes, to the number of bedrooms in each apartment.  (Refer to Figure 11.5, the RD zones of the Los Angeles Zoning Regulations, as an example).

The number of off-street parking spaces required for commercial buildings is often expressed in terms of rentable floor space, which excludes equipment floors and similar non-rentable space.

To prevent the congestion of public streets, specified amounts of loading dock space are often required for commercial and manufacturing uses, as well as office buildings and hotels.

FEDERAL REGULATIONS

In addition to local regulatory controls, it is necessary to comply with any applicable state or federal regulations.  This, of course, depends on the location and nature of the proposed construction.  A state or federal building constructed within a city, such as a state university building or a federal courthouse, need not comply with the city's building and zoning ordinances.  However, as a matter of practice, the Federal or State Government may direct the designer to comply with city ordinances.

Because of widespread concerns about environmental quality, the effects of certain project on the environment must be assessed, through a procedure now quite familiar to architects and planners, namely, the environmental impact statement.  The National Environmental Policy Act of 1969 requires that for every "major federal action" that may "significantly affect the quality of the human environment," the responsible official must prepare a "detailed statement" discussing the environmental impact of the proposed action.  He must also prepare a statement describing any "adverse effects" that cannot be avoided, and any "irreversible and irretrievable commitments of resources" that would be involved.  

This law has become quite far-reaching since it applies to federal construction projects as well as to any action in which there is a "major" federal involvement.  This involvement includes technical or financial assistance, issuance of a license or permit, or other participation.  In addition to the federal requirement, similar requirements have been established in many states and municipalities.

The general topics required in an environmental impact statement depend on the type of site, the building or development program, and the requirements of a particular agency.  Such topics include:

A. RESOURCE INVENTORY

A complete resource inventory of the existing conditions of the region and the project site, including the following general considerations:

1. Landform, topography, location, and size.

2. Vegetation and land use.

3. Soils, geology, and groundwater.

4. Streams and water quality.

5. Wildlife.

6. Climatology.

7. Air quality.

8. Noise conditions.

9. Socioeconomic, demography, transportation, and utilities.

10. Archaeology, and historic attributes.

B. DESCRIPTION OF THE PROPOSED PROJECT

A complete description of the proposed project, emphasizing the way in which the project will affect the environment, including some of the following aspects:

1. Need, public benefit, and economic feasibility.

2. Facilities to be placed on the site.

3. Gaseous, liquid, and solid wastes to be generated from the project; project noise levels; ability to meet air and water quality standards, and noise limitations.

4. Energy and water requirements.

5. Transportation requirements, such as new material imports, product exports, employee traffic, and customer traffic.

6. Manpower requirements, such as expected local recruitment, expected transfer of employees from other areas, and the number of new employees to be attracted to the region.

C. ENVIRONMENTAL IMPACT ASSESSMENT

The environmental impact assessment is the most important part of the process.  It is unique to each project.  It is an evaluation based on a comparative study of the proposed project in relation to the resource inventory of the site and region.  The assessment determines the potential "fit" of the proposed project to its environment, identifies environmental and socioeconomic conflicts, and compares project requirements with available resources.  Sustainable design planning also encourages the architect to make a complete assessment of environmental issues.  But the focus of sustainable design is more affirmative - it attempts to find the virtue of environmental conditions (e.g., topographic slope for potential earth sheltered berming or ground water as a potential energy source).  The sustainable design assessment in conjunction with an environment impact statement can allow the client and architect a good understanding of most of the environmental conditions that will affect the project.

Regarding air and water quality, the impact statement must address the direct and secondary impact of the proposed project during construction and during operation.  The considerations must include both average and worst-case conditions of weather and facility performance.  Such evaluations may result in revisions to a project's design.  The most suitable solutions then determine the final plan.  Less satisfactory designs may be described in a section on "alternative."

D. ALTERNATIVES

Alternatives to the proposed project:

1. Alternative locations for project siting address such questions as: What are the determinants in the selection of a site?  Why was the proposed site selected?  What unique qualities does it provide for the project?  What other sites were considered?  Why were they rejected?

2. Alternative process or methods pose such questions as: In what other way can the goals of this project be achieved?  Why was an alternative process or method not proposed?  Can the proposed project be modified further to avoid or minimize some adverse impacts?  If for example, the project is an electric generating station powered by coal, an explanation should be offered as to why an oil-fired generator was not proposed, or whether hydroelectric generation is possible.  If once-through water is proposed for cooling, the applicant must explain why evaporative cooling towers or dry towers cannot be used.  In the case of a road crossing a marshland, the alternatives of construction on fill, on piles, or on open structures should be discussed.

3. Alternative configurations within the site take into consideration certain sensitive areas within the site that can be preserved by careful arrangement.  An alteration of ingress and egress locations may reduce potential traffic problems.  The appearance of the proposed development from surrounding areas may be improved by adjusting the positions of certain components.

4. The "no-action" alternative examines the consequences of not implementing the proposed project at all.  What public benefits would be lost?  What alternative uses could be made of the site?  What adverse impacts would be avoided?

5. Those adverse environmental and socioeconomic impacts of the proposed project which cannot be avoided are listed in their approximate order of magnitude, and each is described briefly.

These critical points, listed in the environmental impact statement, constitute a basis for regulatory agencies and other interested parties to review a proposed project.  They also serve as a basis of suggestions for reducing the adverse effects of the proposed project.

Most state and local municipalities have authorized a designated official or agency to determine the acceptability of an environmental impact statement, based on its form, content, adequacy of analysis, and suitability of environmentally protective measures.

Public informational meetings and hearing are important components of the environmental assessment process.  In publicly financed projects, public informational meetings are generally initiated in an early stage while the project is still amenable to modification.

In this lesson, we have only touched on the most common types of regulation encountered in the planning, design, and construction of buildings.  In the case of a real project, or course, detailed knowledge of applicable regulations is required.

Lastly, the designer should be familiar with other federal laws that regulate the design of sites and buildings.  Principal among these are the regulations that seek to make buildings and facilities accessible to the physically handicapped (persons of impaired or restricted mobility, the sight-impaired, or the hearing-impaired), and OSHA regulations, which govern the design of the workplace.  Their purpose is to avoid any features that might pose a hazard to the life or limb of a worker.

The proper exercise of environmental regulation confers vital benefits on the public.  Such regulations require constant review and improvement, and they constitute a large part of the design environment in which the architect works.

LEGAL RESTRICTIONS ON LAND USE

The previously described zoning codes represent limitations or restriction on the use of private property.  At the same time they are the basis for sustaining land values, or even increasing them, because unfavorable or possibly harmful land uses are prevented.  There are a number of techniques, in addition to zoning, that protect public health, safety, and welfare.  Architects should be familiar with those discussed in the following pages.

EASEMENTS

An easement is the legal right of a government or a landowner to make use of the property of another landowner for a particular purpose; for example, the right to traverse a neighbor's land to gain access to one's own, which is known as a right-of-way.  To be legal and binding, such an agreement must be in the general form a grant deed.  It must describe the parcel of land subject to the easement, identify the land benefited by the easement, describe the purpose of the easement, and be signed and recorded in the public records.

An easement for a stated purpose may not be unilaterally modified for another purpose at a later date.  If Mr. A has an easement for ingress and egress over Ms. B's land, A may not install a pipeline or water well on the easement.  The land still belongs to B, and A can only use it in the manner originally agreed upon.  Similarly, if the city has an easement over Mr. C's land for the installation and maintenance of an overhead power line, C can still use his land as long as he does not interfere with the power line.

An easement may be established by a municipality for any legitimately constituted public purpose.  Private easements, on the other hand, are always the result of negotiations between private parties.

Normally, the taking of private property by a government for public use requires compensation to the deprived owner.  But there are situations where development rights are taken without compensation, such as the "scenic easement" concept, which has recently come into use.  The purpose of such an easement is to prevent the development of land that is of scenic value to the public.

A similar situation exists where owners of old buildings with historical value have been deprived of the right to alter or rase them, but have not been compensated for the loss of their right to modify or dispose of their property.  This apparent inequity is likely to be adjudicated in the courts in due time.

DEED RESTRICTIONS

Any clause in a deed which restricts the future use of a parcel of land by the buyer of the land is a deed restriction.  Deed restrictions can be quite broad; for example, they may limit the type, the density, or even the use of buildings on a site.  This type of agreement is enforceable between buyer and seller, and sometimes third parties.

A covenant is a legal agreement used to protect or uphold a condition of use in a parcel of land.  Where a seller owns two adjoining parcels, restrictions on the one sold may benefit the parcel retained, and are legally enforceable.  As an example, Ms. D owns two adjoining lots fronting a street and backing on a public alley.  She sells one lot to B with the covenant that B may not construct a driveway from the street to the garage, but may have access to the garage only from the alley.

If a developer establishes uniform restrictions on buyers of lots in a development for purely aesthetic reasons, the developer and other owners have a valid cause of action against an owner who violates the restrictions.  When all the lots are sold, the developer will no longer have a legal standing for action against an owner who violates the restrictions.  To provide for continuing enforcement, therefore, a developer may create a homeowners' association, whose members comprise all the original buyers.  The association is empowered to enforce the restrictions for their mutual benefit.  Such an association may include an architectural review board which is authorized to approve all proposed designs according to criteria established in the deed restrictions or covenants.

Affirmative covenants are those that legally commit a buyer to perform certain duties in the future, such as maintaining a fence or a roadway.  Such covenants run with the land, so that future owners or record will always be responsible to perform the same duties.  Affirmative covenants are also used to require buyers of planned unit developments and condominiums to make payments for the maintenance of common areas.

Still another form of restriction is a clause that imposes a restriction on a buyer and specifies that if the restriction is violated, the title to the land will revert to the original grantor or his heirs.  Such an arrangement is known as a conditional covenant or condition.

Some deed restrictions expire after a definite time, but others may run indefinitely.  In the latter case, a restriction can sometimes be eliminated by court action.  Deed restrictions involving race or religion have been ruled invalid by the U.S. Supreme Court and are of no effect, even though they may still appear in recorded deeds.

The right to use the open space above land or above an existing structure is known as an air right; for example, the right to construct a building over a railroad track.  An air right is a form of easement, and usually includes the right to construct foundations for and provide access to a structure built in the space.  All such matters must be specified in detail in the agreement conveying the air right.  Air right construction is costly, and therefore occurs infrequently and only where land is very expensive, as in the central areas of large cities.

A party wall is a wall located on an interior lot line that forms part of two adjacent buildings.  A party wall is also a fire wall, and must be constructed accordingly; however, it is usually more economical than constructing two separate walls.  Where adjoining buildings are under different ownership, an agreement must be reached by respective owners prohibiting either owner from tearing down or significantly altering the party wall without the concurrence of the other owner.  When the agreement is written and recorded, each owner has an easement on the other's land to the extent of one-half the thickness of the wall, and the agreement cannot be revoked unilaterally.

BUILDING CODES

Building codes and zoning ordinances have distinctly different purposes.  As we have seen, zoning ordinances prescribe land usage and regulate the function, size, and certain exterior aspects of a building.  In contrast, a building code deals with the structural and mechanical aspects of a building, as they affect public health, safety, and welfare.  Building fires have caused countless deaths.  The earliest building codes, therefore, were primarily fire-protection codes concerned with preventing fire, and allowing occupants to evacuate a building quickly and safely.  In time, other hazards came to be recognized, such as earthquakes, wind storms, power supply failures, and the danger of panic that is likely to occur in crowded spaces.  The concern for public health is manifested in codes which deal with plumbing, ventilation, electricity and lighting.

There is a number of building codes that are being used as follows:

THE UNIFORM BUILDING CODE (UBC)

Used as the model code throughout all ALS study material and it is published by the International Conference of Building Officials.

THE STANDARD BUILDING CODE (SBC)

Published by the Southern Building Code Congress International and is used by some Southern states.  Most have used it as the base code for their state specific building codes.

THE BOCA NATIONAL BUILDING CODE

Published by the Building Official and Code Administrators, and is still being used in a few states, mostly in the Northeast.  This code was last published in 1999 and states that use are either changing to the International Building Code (IBC) or revising a model code to make it state specific.

All of these model building codes mentioned above are in use in some states, but in the last ten years the Southern Building Code Congress International and the Building Official and Code Administrators, in an effort to standardize Building codes, developed the International Code Council.  They created the International Building Code (IBC), which has been adopted in most states to date.

The National Research Council of Canada published the National Building Code of Canada.

A building code is enforceable because the government having jurisdiction (city, county, etc.) has adopted the particular code by establishing it as law.  It should also be noted that a municipality usually adopts a particular edition of the code, which remains in force even when a later edition of the code is published.  In addition, the code may be adopted with specific additions, deletions, or alterations.  Some large cities write and adopt their own building codes.  And an increasing number of cities are adopting energy codes from a variety of models.  One example used by large cities such as Chicago is the IECC (International Energy Conservation Code), a model energy code that can be modified to fit the needs of individual communities.

TYPES OF CODES

There are two types of building codes: the first specifies construction techniques, methods, and materials in detail, while the other establishes the functional requirements that a structure that a structure must satisfy under specific conditions.  The first, referred to as a prescriptive code, is simply to administer, but discourages innovation.  The second, known as a performance code, promotes innovation in building design, but it may be difficult to administer.  Of course, innovative or unconventional designs must be tested and proved to the satisfaction of code administrators.  This may entail tests, which must be paid for by the owner.

Terminology may vary from one code to another.  For example, one code may use the term "exit" while another may refer to "means of egress" and still another may speak of "exit-way."  Each code includes definitions of such terms, and these must be noted carefully.

BUILDING CODE CHARACTERISTICS

An outline of the basic steps in determining code compliance for a building design follows:

1. CONSTRUCTION DOCUMENTS

Determine compliance with the requirements for construction documents.

2. USE GROUP

Determine the appropriate use group classification of the building.

3. HEIGHT AND AREA

Determine the type of construction required based on the building use group and the height and area limitations.

4. TYPE OF CONSTRUCTION

Determine compliance with the required type of construction of the building by the building materials used and the fire resistance rating of the building elements.

5. SITING

Determine the location of the building on the site, including separation distances from lot lines and other buildings.  Determine exterior wall and wall opening requirements based on proximity to lot lines and adjacent buildings.

6. FIRE PERFORMANCE

Determine compliance with detailed requirements for fire resistance and fire protection systems.

7. INTERIOR ENVIRONMENT AND DESIGN

Determine compliance with special use and occupancy requirements, means of egress requirements, accessibility requirements, and interior environment requirements.

8. EXTERIOR ENVELOPE

Determine compliance with exterior envelope requirements, as well as energy conservation.

9. STRUCTURAL PERFORMANCE

Determine compliance with structural requirements and building material requirements.

10. BUILDING SERVICE SYSTEM

Determine compliance with various building service system requirements.

These classifications establish requirements of the code that are applicable to a specific building.

FIRE ZONES

Some jurisdictions establish fire zones, which are geographic districts generally classified as high hazard, moderate hazard, or low hazard.  The criteria for such classification include: population density, building height, street access and congestion which affect the fire department's equipment and competence.  Buildings in high hazard fire zones require greater fire resistance and other protective features than buildings located in less hazardous zones.  In fact, certain forms of combustible construction are entirely prohibited in high hazard fire zones.

The fire zone of a particular site should be determined and considered during the process of site selection, so that its effects can be determined in the programming phase.  Because certain uses are prohibited in specific fire zones, the investigation of this matter can be critical.

OCCUPANCY GROUP

The number of occupants and the nature of their activity are important considerations in building codes.  For example, night clubs and theaters have an inherently high risk of panic, and therefore warrant higher than normal levels of fire-resistive construction.  Those who are not able to move easily, such as hospital patients and prison inmates, are in greater danger than more mobile people.  Therefore, such people must be accorded the protection of greater fire resistance and other related safety features.

The occupancy classification (use-group) of a structure is determined by the activities for which the structure is intended; for example, public assembly, school, manufacturing, etc.  The degree of hazard in an occupancy is determined by the amount and form of combustible materials normally present in a building, such as flammable gases, explosive dusts, paints, and varnishes, and waste paper.

Combustible materials that are stored, such as furniture, clothing, lumber, etc., pose less risk of fire than combustible materials that are processed.  Inert materials such as glass, canned foods, metals, etc., are generally assigned a low hazard rating.  Of course, certain materials can be atypical of their classification: for example, magnesium is a highly flammable metal when in powdered or shredded form.

When two or more occupancies are present in the same building, the code usually requires a fire-rated separation between them.  The resulting additional construction costs must be considered in preparing budget and cost estimates.

The use of a building is legally designated by a so-called "occupancy" or "use" permit.  That designation cannot be changed unless the building is altered to comply with the requirements of the proposed new use.

TYPE OF CONSTRUCTION

All buildings must conform to specific types of construction which are classified according to the degree of their fire resistance.  These classifications range from highly fire-resistant to wood frame construction, and they are usually designated by type numbers arranged progressively.  A major effect of building codes is that the principal components of a structure, such as the structural frame, floors, and walls, are made fire-resistive.  Certain elements of the building envelope, such as the roof and doors, may also by fire-resistive.

The type of building construction permitted on a particular site is determined in accordance with the applicable building code, the fire zone in which the structure is located, and the intended use of the building.  Similarly, the type of construction specified has a great influence on the structure's height, floor area, and construction materials permitted.

SITING OF STRUCTURE

The location of a structure on its site must take into account the possible spread of fire to or from an adjacent structure.  In this regard, setbacks and alleys can serve as effective firebreaks.  The fire resistance required of exterior walls is determined in part by the actual (or potentials) nearness to structures on neighboring lots.  Similarly, openings in exterior walls may be severely restricted or even prohibited, depending on their proximity to adjacent lots and structures.

Where two or more buildings on the same site are separated by a court, the court constitutes a firebreak.  This influences the fire resistance of facing walls, as well as the permissible openings in those walls.

FLOOR AREAS

Codes normally specify the maximum permitted floor area for a one-story building based on its use, construction type, and fire zone.  These maximum allowable areas, however, may be increased in relation to the fire-resistive design of the structure, which is determined by the materials used as well as fire-fighting devices provided, such as sprinklers.  Multistory buildings, as well, are usually permitted a significant increase in total floor area by the addition of an automatic fire extinguishing system.

If the permitted floor area of a building is inadequate, the building code may permit a larger building to be built if it is subdivided into discrete fire-resistive areas.  These areas are established by constructing full-height, fire-resistive interior walls.  When this is done, the area between separation walls is regarded as a separate building in order to satisfy the floor area requirements of the code.  Separation walls must extend from the bottom to the top of the structure to provide the necessary legal division.  Any openings through fire walls must be protected by automatic closure devices, as required and described by the building code.

HEIGHT

The height of a building permitted by code is generally determined by both its use and type of construction.  The incorporation of an automatic fire extinguishing system usually allows an increase in building height.  When the most fire-resistive type of construction is employed, the permitted height of a building is unlimited.

OCCUPANT LOAD

The allowable number of occupants in a building is specified by code on the basis of use, with a given number of square feet of floor area allocated to each occupant.  These values range from approximately 7 to 500 square feet per occupant.  The lower figure applies to assembly areas without fixed seating; the higher figure applies to warehouses, aircraft hangars, and other similar storage areas that are generally used by few people.

To summarize the preceding building code characteristics, let us consider the example of an eight-story department store of 320,000 square feet located in a downtown area and determine its classification under the Uniform Building Code (UBC).

1. Occupancy Group B, Division 2, based on occupancy description in Table No.5-A of the UBC.

2. Type 1 Construction, because it has unlimited floor area, height, and number of stories.  See Tables No.5-C and No.5-D of the UBC.

3. An Occupant Load of 6,000 persons, based on Table No.33-A of the UBC, which specifies 30 square feet per occupant on the ground floor and 60 square feet per occupant on upper floors.  (40,000/30 + 280,000/60 = 1,333 + 4,667 = 6,000).

Since individual codes differ, one must always comply with the code applicable to the specific project being analyzed.

FIRE RESISTANCE

Fire resistance requirements serve several purposes.  One is to permit the safe egress of the occupants in the event of fire.  A second purpose is to maintain structural integrity and limit the spread of fire long enough for firefighters to extinguish a blaze.  A third purpose is to provide sufficient protection to the structure to limit damage and avoid collapse.  The major components of a building's structure are assigned minimum fire ratings by the code, depending on the fire zone, the building type, and the use of the building.  Fire-resistance values are stated in terms of hours, and are required for the structural frame, the floors, walls, ceilings, roof, doors, and windows.  Fire resistance is generally increased when automatic fire-extinguishing systems are incorporated.  Required fire-ratings range from 3/4 to 4 hours.  The higher values apply to exterior walls, hazardous areas from adjacent areas with large occupancy loads.

It should be noted that a noncombustible structural material is not necessarily fire-resistant.  Steel loses its strength and quickly distorts or collapses when subjected to high temperature.  A fire-resistant building must have structural elements that are capable of withstanding heat for a definite period of time without collapse.  Materials such as concrete, gypsum, or vermiculite plaster are used for this purpose.  Their thickness is determined by the fire-resistive period required and the type and quality of insulating material employed.  The use of asbestos for such insulation is now prohibited because it is carcinogenic.

Some codes specify in detail the construction of walls, ceilings, and other common building components, which satisfy various fire-resistive ratings.

FLAME AND SMOKE RATINGS

Flame-spread ratings and smoke-developed ratings are measures of the amount of flame and smoke generated by specific materials.  Paint finishes and carpets are examples of rated materials.  The ratings are established under standardized test conditions and are often used in specifying materials to be provided by contractors or vendors.  Specifiers should be cautious of flame-spread ratings when materials are applied to large areas, since testing is performed on small samples.  Caution should also be exercised with furnishings placed in buildings after completion, since they may greatly increase both smoke and flames in case of fire.  Plastic and other similar materials now in use also contribute greatly to building fires, and they often generate highly toxic smoke as well.

EXITS

A major aspect of all building codes is the provision of adequate exits from a building.  Generally, the required number of exits is based on the number of occupants, with a minimum of two.  Exits should always be separated in such a way that a single fire or other emergency cannot block all the exits simultaneously.  

The total width of exits required for a building floor is determined by the total occupant load of that floor plus an additional allowance for occupants of floors above and below that floor, if those occupants must use the same exit routes.  The width is usually calculated by dividing the total number of occupants to be served by a factor, such as 50, resulting in a total exit width expressed in feet.  Another method found in some codes requires a "unit of exit width" for each 50 to 100 occupants, the number of occupants being determined by a table in the code.  Typically, a unit of exit width is 22 inches, with an additional half unit credited for each additional 12 inches of clear with.

Minimum widths of corridors, doorways, and stairways are specified by code, based on the use of the building.  In some cases, the installation of a full sprinkler system permits a significant increase in the allowable number of occupants per unit of width, thus reducing the amount of circulation space required.  The characteristics of required exit routes are usually specified by the code in some detail.  These generally include: length, width, fire resistance of the enclosing surfaces, permitted length of dead-end corridors, lighting, directional signs, and ventilation.

Current practice also provides for an automatic ventilation control system which increases the air pressure in designated exit passages, thus preventing the flow of smoke into them.

The distance that an occupant must travel from any location in a building to a legal exit is usually limited to 150 feet in an unsprinklered building and 200 feet in a fully sprinklered building.  Once the person has reached an enclosed exit passage, he or she is adequately protected from fire and may travel a lengthy route from there to a safe place outside the building.

Despite detailed exiting requirements, building codes cannot communicate to building occupants the critical evacuation procedures that may save lives.  That must be done by periodic fire training and drills, which are often required by municipal law and fire insurance companies.

STAIRWAYS

Interior enclosed stairways must be protected by fire-resistant construction, the extent of which depends on the use of the building.  Stairways that serve as required building exits must meet numerous detailed requirements described by the code.  The width, handrail location, rise and run of the steps, size and location of landings, and headroom are all specified.  The materials of construction and the fire ratings of the enclosing walls, ceilings, etc., are also specified, usually of one-hour rating.

In structures that are 75 feet high or greater, at least one of the required exits must be a smoke-proof tower, which is also known as a "fire tower" or "smoke-proof enclosure."  A smoke-proof tower consists of an enclosed stairway of noncombustible construction which is connected to interior areas of the building by balconies, open air vestibules, or mechanically ventilated vestibules.  The intent is to prevent smoke from entering the tower, thereby creating a refuge through which occupants may exit a building.  Not all codes permit mechanically ventilated vestibules, since their reliability depends on an uninterrupted electric power supply.  Some codes require mechanical ventilation of smoke-proof towers during an emergency, while others require a specified rate of air change by either gravity or mechanical circulation.  If mechanical ventilation is used, the electrical power system must have emergency capability provided by an automatic and independently powered generator, or a reliable bank of charged batteries.

Ventilation systems should be designed to minimize circulation of smoke from a fire area to other parts of the building.  This may be accomplished by isolating the circulation system of each fire area from that of every other.  Another approach is to incorporate a circulation system which automatically shifts from normal operation to total exhaust when a fire is detected in the area.  Some systems automatically increase the air pressure in corridors and vestibules, as previously mentioned, so as to prevent the flow of smoke and fumes into them.  Thought should be given to the location of outside air intakes, in order to minimize drawing in smoke-laden air exhausted from a fire elsewhere in the building.

PANIC

The possibility of panic during an emergency requires careful consideration, although it is not specifically detailed in the building code.  A major factor in causing panic is the inability of a crowd of people to see escape routes clearly.  The normally recognizable exits may be obscured by smoke, lack of light, or inadequate signage.  Exit signs are particularly important and should be considered from the design stage through fixture specification.  They should also be reviewed when partitions and doors are altered in the future, to ensure that escape routes remain accessible and clear.

In certain buildings, such as places of assembly, exit doors must be equipped with panic hardware, consisting of a horizontal bar on each door leaf, actuated by pressure in the direction of egress.

Exits and exit signs must be illuminated when a building is occupied and during emergencies.  Their illumination power circuits must have greater reliability than general illumination lighting, but the means of providing this varies from one code to another.  Special circuits connected ahead of the main breaker for the building may work well in some cases, but in others an independent source of supply may be necessary, such as batteries or an engine generator.  The applicable electrical code will usually specify the requirements in detail. 

In some situations, the building code may require public address equipment, called an "enunciator," to broadcast prerecorded or live messages to instruct occupants in the emergency evacuation process.

VERTICAL TRANSPORTATION

Elevators are unacceptable as emergency egress from a building for the obvious reason that loss of electric power renders them useless and, worse, a trap for anyone caught inside.  In addition, heat actuated elevator call buttons may direct elevators to the floor where a fire is located.  In high-rise structures, many elevator shafts have no hall doors in the express portion of their travel.  The occupants of  car stalled in this region, therefore, cannot escape, even through the elevator roof hatch.  In addition, a car may be called to the fire floor, and it may stall there due to the panic-stricken crowd or because the door-closing photocells are obstructed by people or smoke.

Some codes require that an elevator must be available for use by firefighters during a fire.  The reason for this is that a fire floor in a skyscraper may be so high that it would be impractical for firefighters, burdened with hoses and other equipment, to reach the fire on foot.  Such special elevators should have manual override controls and be free from the entrapment hazards of normal elevators.

Escalators penetrate floors and thereby provide a conduit for smoke and flame from one floor to another.  Three methods are available for controlling this hazard.  The first safeguard is an automatically operated rolling shutter door to seal the floor opening of an escalator.  A second method consists of enclosing the escalator in a structure similar to a stairwell, with fire-rated enclosures and doors at each floor level.  The third approach requires the installation of a sprinkler and automatic ventilation system to protect the escalator opening on each floor against smoke and flames.

OTHER EXITWAYS

Ramps designed in accordance with the code may constitute a portion of the required legal exits from a building.  However, escalators and moving sidewalks are not permissible as approved exits, since they may be operating in the wrong direction at the time of a  fire.  Revolving doors are sometimes permitted, depending upon the particular code, and in those cases the revolving doors must be collapsible.  Pressure applied to opposite wings of such doors causes the wings to fold against each other in the direction of travel, opening both sides of the doorway as exits.  However, a revolving doorway cannot always be counted as part of the required exit width due to uncertainty of use and limited effective width due to uncertainty of use and limited effective width, even with the wings collapsed.

PLACE OF REFUGE

The evolution of fire safety techniques in high-rise buildings has brought about the concept of a place of refuge during a fire.  A floor space on the same level, but in a different part of a building or in an adjoining building, may serve as part of the required exit from a fire area.  The place of refuge must be separated from the fire area by an adequately rated fire separation.  In addition, there must be means of egress from the place of refuge; it cannot be a dead end.  This method reduces the crowding of stairwells, which often occurs during the evacuation of large numbers of people to street level.  It also provides quick access to a place of safety for the occupants; it lessens the need to descend many flights of stairs, which is tiring and time consuming; and it permits freer access by firefighters, there being fewer occupants in the stairwells.  The floor area of the place of refuge must be adequate to accommodate both the normal occupants and those departing the fire area.

STANDPIPES

Codes may require several types of standpipes, depending upon building use, floor area, and building height.  Standpipes are required for buildings of three or more stories.

Wet standpipes are continuously pressurized with water from a public source, a house tank, or other permanent water supply.  They are connected to readily accessible hoses, in cabinets, so that they can be used easily by building occupants.  There is usually a requirement for a fire department connection to a siamese fitting, which permits the fire department to increase water pressure and flow in the wet standpipe.  Fire hose cabinets must be installed and provided with hoses of specified sizes and lengths.  The location of the cabinets is determined by the requirement that at least on hose and nozzle must reach a specified distance to every point on its floor.

Dry standpipes, in contrast, are not connected to a constant source of supply, but have only a siamese fitting for the fire department connection.  Being dry, they are not subject to freezing in cold weather.  They are generally located in smoke-proof stair towers and in enclosed stairways, for the exclusive use of the fire department.  The requirements for dry standpipes vary widely from one code to another.

Combination standpipes are pressurized by a constant water supply and have a fire department siamese fitting.  They serve both the occupants and the fire department, but are primarily used by the fire department.  Not all codes allow combination standpipes.

Water supplied through wet or combination standpipe systems must flow at a specific rate, pressure, and time through a specified number of hoses, all of which constitutes the flow rate, expressed in minutes.  A typical requirement for a wet standpipe is the ability to deliver 35 gpm (gallons per minute) from each of two outlets simultaneously for 30 minutes duration while maintaining 25 psi pressure at the outlets.  This amounts to 2,100 gallons of water storage if a roof tank is used, but the required capacities vary widely from one code to another.  Some codes require two sources of water supply under emergency conditions, and this may require the installation of a fire pump on the premises.  If a fire pump is electrically driven, consideration must be given to the reliability of the electric power system.  Engine-driven pumps are also available.

Building codes impose numerous safety requirements on projects during their construction phase, especially in the matter of fire protection.  If standpipes are a part of the building design, they must be carried upwards, floor by floor, as construction progresses and kept in working order for immediate use at any time.

SPRINKLERS

Sprinkler systems are required by certain codes in specific situations, and may be optional in other situations.  Automatic sprinklers are normally required in high hazard areas, such as high-rise hotels, vaults for storage of flammable film, paint spray booths, hazardous parts of theaters, some types of garages, and certain hazardous basements.  But there is wide variation in the requirements of different codes.  In general, installation of an automatic fire extinguishing system in areas where it is not mandatory increases the allowable floor area between fire-rated walls, or decreases the number of required exits.  These economic incentives are often referred to as design "trade-offs."  Sprinklers have a proven record of success in preserving life and property, but their high cost discourages their installation where not required by code.

As economic advantage of sprinklers is the reduced fire insurance rates applicable to a fully sprinklered building.  The savings in insurance costs may well offset the initial costs of the full sprinkler system.  A developer who plans on selling a building soon after completion, however, may decide to save money by omitting sprinklers and leave the increased fire insurance premiums to later owners.  An institutional owner, on the other hand, may find it advantageous to do the opposite.

In light of recent fire deaths and injuries, it is clear that the public has a moral responsibility to insist that codes mandate the use of sprinklers in areas where their effectiveness in saving life and property has been clearly proven.

FIRE-RATED DOORS

Fire-rated doors are required to maintain the integrity of separation walls between fire areas.  Windows are often provided in such doors to permit people approaching from opposite sides to see each other, and thus avoid collision.  Such windows must be glazed with wire glass of restricted total area penetration by fire.

In areas of low or normal hazard, the code may permit fire doors to be held open under conditions of normal use, and closed automatically by springs or weights in the event of fire.  Such doors may be held open by a fusible link which melts at a moderate temperature, or by an electro-mechanical device that is activated by a sensor responding to heat, smoke, or alarm system impulse.

As a general rule, whenever a separation between two fire areas is pierced by an air duct, an automatic fire damper (or fire assembly) must be installed.  It is designed to close when activated by excessive temperature or smoke.  The duct must be constructed so as to reduce the spread of fire through it.

FIRE ALARMS

Fire alarm systems are required in buildings such as hotels, schools, and other places of assembly.  The systems are of two basic types: the first operates a local alarm on the premises only, while the second type additionally transmits a signal to the fire department.  Such systems may be manually operated, or they may be equipped with automatic fire sensors.  There are three basic types of sensing elements: fixed temperature sensors, which respond to ambient air temperature; smoke detectors, which respond to obstructing a light beam by smoke; and product-of-combustion detectors, which are activated by an interruption of a light beam or by ionization effects.

LOADS

LIVE LOADS

Buildings must be designed to resist dead load (the weight of all the permanent parts of a building) plus live load.

Building codes specify the minimum live loads required for the design of floors and roofs.  The design live loads on floors vary according to use, ranging from 40 to 250 pounds per square foot.  The lower value is for occupancies such as dwellings, while the higher values are for heavy storage.

Roof live loads include those caused by people, equipment, materials, and objects, the design values of which are specified in the code.  Snow loads are determined locally or regionally based on available snowfall records.

LATERAL LOADS

Lateral loads are of two types: seismic (earthquake) and wind.

The prevention of seismic damage to structures is considered by building codes in earthquake-prone areas.  The underlying philosophy is as follows:

1. A structure whose foundation is situated on an earthquake fault is not expected to withstand the effects of an earthquake.  However, every structure should be able to resist the effects of an earthquake occurring in a nearby fault.

2. A building should remain sufficiently intact to permit reasonably safe and rapid exit by its occupants.

3. Some components of a structure may fail, but the structure as a whole must not collapse.

A seismic zone map, such as that in the UBC, shows the degree of seismic risk in a given area.  Design methods are also described in the code, based on research and the behavior of structures in past earthquakes. 

Wind load design requirements are based on location, as shown on a map, and height above grade.  For design purposes, building codes do not require that structures be able to withstand the effects of wind and earthquake simultaneously.

OTHER CODE REQUIREMENTS

Sanitation, ventilation, and illumination requirements are also covered by building codes, even though they are given less detailed attention than fire and other life safety hazards.

Toilet rooms and other sanitary plumbing facilities are covered in detail.  In places of public assembly, separate water closets and lavatories must be provided for each sex.  In addition, public water fountains are required.  In larger work places, separate lavatory facilities are required for each sex.  Food handling establishments are also subject to particular requirements, such as isolation of water closets from food preparation and storage areas.

The number of water closets, urinals, and lavatories in schools is normally based on the maximum student population expected.  Codes, also consider light and ventilation for spaces in general, while the ventilation requirements of toilet rooms are specified in greater detail.  The required amount of ventilation is expressed in terms of cubic feet per minute (cfm) per occupant, minutes per air change, or air changes per hour.  The air from toilet rooms, kitchens, and other odorous areas must be exhausted, and not recirculated.  

Building codes often refer to specialized codes pertaining to individual trades such as electrical and plumbing.  Where such references are made, performance, quality, and standards must meet the requirements of all governing codes.  Sustainable design requires special attention to the type, quality, performance, and installation standards for design elements.  (Sustainable design products often have unique performance standards governing the installation of products that need to be carefully specified).

OTHER CODES

In 1970, a new set of federal standards came into existence, known as the Occupational Safety and Health Act, or OSHA.

While its original purpose was to provide safe and healthy environments for employees, its practical effect was to create a whole new set of standards applicable to structures throughout the country.  The standards are relevant to all projects during construction, and are predicated on the fact that construction work is inherently hazardous.  It normally applies to work places such as factories, offices, and warehouses, but residences are exempt after construction is completed.

Among the factors regulated by OSHA are: fire protection, scaffolding, electrical installations, ventilation, exposure to air contaminants, noise, and radiation hazards.  In some instances existing codes were incorporated by reference into OSHA, such as the National Electrical Code, which makes it enforceable on a national scale.  In other cases, new sections of code material were written.  The requirements of OSHA are enforced by both state and federal officials, prompted in some cases by labor and employee groups.

Architects must learn how the OSHA code applies to their projects.  Generally, the contractor is responsible for OSHA regulations during construction, but there are, inevitably, "gray areas" where responsibility is unclear.

The National Fire Protection Association (NFPA) develops more than 300 codes and standards adopted by different states and municipalities, in addition to their model codes.  NFPA codes tend to be more restrictive than a standard code and in most instances, they govern.

Other standards that may concern the architect are those issued by the Federal Housing Administration (FHA), particularly "Minimum Property Standards for One and Two Living Units," FHA #300, and "Minimum Property Standards for Multi-Family Housing," FHA #2600.  These cover many of the same areas as various building codes and are imposed upon residential construction financed by federally-guaranteed loans.  Where building code and FHA standards differ, the more restrictive requirement is generally enforced.  Sometimes a local code and FHA standard may conflict, in which case the difference is negotiated by the enforcing agencies, based on the practices of both.

SUMMARY

Building codes and other regulatory guides are in existence to maintain and constantly improve the safety and welfare of human life, and are to be used by architects as a minimum standard while reaching for a design objective.  It is ultimately the responsibility of the architect to ensure that the project meets or exceeds the expectations prescribed by regulatory agencies and authorities possessing jurisdiction.