Codes, Standards, and Rating Systems
It is past time for the construction and regulatory industries to
establish minimum standards for the performance of buildings in relation
to resource consumption including but not limited to water, energy,
and land. A green construction code is the clearest way toward developing
a strong foundation for this effort. That raises the question: What
are the fundamental differences among rating systems, standards,
and codes? This is a question we field frequently from architects
and others in the building industry, and to help frame the rationale
for creating the new International Green Construction Code, we’ve
outlined a comparison of these three different concepts below.
Building codes are an enforceable body of rules that govern the design,
construction, alteration, and repair of buildings. Code books are
an essential aid to architects, engineers, designers, and builders
for creating buildings that comply with the code adopted by a jurisdiction.
Such codes are based on requirements for the safety, health, and
quality of life of building users and neighbors, and vary from
city to city, state to state. Model codes developed by a consensus-based
process of stakeholder groups are typically adopted by local communities,
with local amendments respective of climate and regional construction
Municipalities generally adopt codes on a three-year cycle and employ
building officials to review and recommend code adoptions or revisions.
The established review process allows a code to take into consideration
appropriate local conditions affecting the sustainability of resources
particular to the region. Once adopted, the code becomes a clear
and unwavering guide to the architect with responsible control of
the project until the next cycle of that code is adopted, and it
becomes part of the standard of care an architect must follow. An
established code development cycle provides architects and building
officials with the opportunity to understand new code requirements
and work together in applying these requirements, assuring the public
of a reasonable level of and application to their project, ensuring
the protection of health, safety, and welfare.
Building codes, as the governing body of rules over a jurisdiction
for buildings, are not intended to be flexible and are enforceable
to the letter of the code or, as code officials say, “compliant
with the minimum standard.” Unlike standards and rating systems,
codes are not optional or permissive once adopted. Building codes
are written in precise language meant to be enforceable. An example
of compliance language from the 2006 IRC:
N1101.2 Compliance. Compliance shall be demonstrated by either meeting
the requirements of the International Energy Conservation Code or
meeting the requirements of this chapter. Climate zones from Figure
N1101.2 or Table N1101.2 shall be used in determining the applicable
requirements from this chapter.
An ICC code effort is an important step in establishing accepted,
uniform national minimum standards toward the creation of highly
sustainable and resource-efficient architecture.
Standards, for example the ICC 700 National Green Building Standard
or ASHRAE 90.1, typically outline a series of options for performance
of building systems and assemblies and are often referenced by
codes but are not strictly enforceable due to the provisions for
multiple options, unless adopted by a jurisdiction as its code,
which is rare and presents problems, as they are not meant to be
enforceable. Standards do not reference codes, whereas codes sometimes
reference standards as options for compliance.
A standard is most appropriately applied to things that everyone
does that are not quite regulation or are considered optional and
then are agreed to by a consensus of stakeholders (see below). This
use derives from the American National Standards Institute (ANSI)
as well as the International Organization for Standardization (ISO)
standards. Architects, consulting engineers, and builders are the
most common audience for standards, looking to the documents for
options when approaching the design and construction of code-compliant
Many of the mandatory measures found in the National Green Building
Standard are consistent with the International Code Council's I-Codes.
Additionally, the baseline for energy savings has been updated to
the IECC 2006. To qualify for "Bronze" in the energy efficiency
chapter of the ICC 700, a home must be at least 15 percent better
than the 2006 IECC (ENERGY STAR™ equivalent).
An example of compliance language in a standard, in this case ICC
701.1.1 Minimum Performance Path requirements. A building complying
with Section 702 shall exceed the baseline minimum performance required
by the ICC IECC by 15 percent, and shall include a minimum of two
practices from section 704.
From ANSI’s Web site:
Building rating systems
Historically, a rating system, such as fire safety ratings of materials
or other safety rating systems, was referenced in the code to describe
acceptable minimum requirements for materials or systems in a building.
Independent bodies test and rate the products or materials and
an official label and documentation would be required for the product
before offering it in the marketplace, subject to on-site inspection
by a code official. Since the emergence of total or green building
rating systems, the purpose has spread from safety to energy and
environmental impact, and through the development of a complex
series of prerequisites and options, rating systems strive to rate
the overall performance of a building. Unlike product safety rating
systems, green rating systems are intended to be voluntary. But
in recent years, due to a lack of enforceable green codes, states
have begun to incorporate them into requirements for public or
state owned construction.
There are now two established building rating systems in the marketplace.
In response to architects’ questions about how current rating
systems in the marketplace stack up to the goal of reaching carbon
neutral buildings by 2030, the AIA developed a position statement
on rating systems outlining 16 major criteria. The AIA maintains
a position of neutrality regarding rating systems currently available
in the marketplace to promote the choice of the best tool for each
individual project, act as a voice for its members to address concerns
about those systems, and act as a collaborative critique for continuous
improvement of all rating systems as tools for architects and the
building, design, and construction industry. Rating systems can be
modified on a more frequent and less regulated cycle, which can create
a set of unique challenges to design professionals and owners seeking
to use the rating system.
Rating systems are typically above and beyond code—they aspire
to a set of criteria for construction and performance, not minimums.
To use the carrot/stick metaphor, rating systems are a carrot system,
rewarding above-and-beyond performance, while a building code enforces
penalties for not meeting a minimum. The rating systems are owned
by, administered for, or otherwise operated by nonprofit organizations
or local governments and may generate profits either for the owner
organization or for the rating body or individuals commissioning
the building to that system. There is an emerging cottage industry
associated with the rating of buildings that is independent of the
licensing requirements for professionals such as engineers and architects.
If a jurisdiction calls for compliance with a rating system, it
has been effectively codified. But enforcement of the requirement
presents some challenges to the jurisdiction, introducing tremendous
education and training hurdles for code officials, depending on the
complexity of the rating system. If a rating system is tied to a
code in some way, codifying the rating system effectively enforces
that code. Building officials are able only to enforce a code and
does so by plan review, inspections, and permits (with related fees)
received by the municipality governing the project. A building official
is not necessarily legally obligated trained to, or has the staff
to enforce a rating system. Their time is sometimes not compensated,
as fees are paid to a rating organization, not the municipality.
Thirty-six states have public building requirements that call out
at least one rating system. Examples of ratings systems include LEED,
Green Globes, and Energy Star.
Below is an example showing how a rating system treats complying
to a building performance line item in a standard, in this case EnergyStar:
To qualify for the ENERGY STAR, a building or manufacturing plant
must score in the top 25 percent based on EPA's National Energy Performance
Rating System. To determine the performance of a facility, EPA compares
energy use among other, similar types of facilities on a scale of
1-100; buildings that achieve a score of 75 or higher may be eligible
for the ENERGY STAR. The EPA rating system accounts for differences
in operating conditions, regional weather data, and other important
Rating systems go beyond outlining an industry’s consensus
on a topic by starting with standards-level definitions and outlining
options that correlate to a rating level, such as LEED Silver or
Energy-Star “compliant.” At times, because the system
may be owned by an organization or governmental body, they may not
be developed with consensus input of all stakeholder groups; rather
a select group favorable to that organization. Next-generation rating
systems, such as the Living Building Challenge, go beyond the options
and set strict prerequisites for building performance.