RESPONSIBILITIES FOR SEISMIC CONSIDERATIONS WITHIN THE DESIGN 
TEAM 12 

12.1 	RESPONSIBILITIES OF THE STRUCTURAL ENGINEER, ARCHITECT, 
AND MEP ENGINEER 

Seismic considerations should apply to every building system, subsystem, and 
component, and the performance of each component or system is often 
interdependent.  The traditional organization of the design team and the 
assignment of responsibilities to the architect, structural engineer, MEP 
(mechanical, electrical, and plumbing) consultants, and other specialty 
consultants (e.g., geotechnical engineer, curtain wall consultant, elevator 
consultant, or security consultant) is critically important to address cross-
cutting seismic design issues or problems. 

For example, the seismic design and performance of glazing systems, 
windows, and curtain walls have improved significantly in recent years through 
the adoption of improved code provisions for these building systems.  These 
improvements can impact both life safety in an earthquake (broken glass can 
kill or seriously injure) and immediate occupancy following an earthquake 
(integrity of the building envelope). The trade-offs involve drift limits, curtain 
wall 
clearances and design details, and glazing design.  In this example, the 
architect, structural engineer, and curtain wall consultant must work together 
closely to arrive at the appropriate designs. 



12.2 DEVELOPING A UNIFIED APPROACH WITHIN THE DESIGN TEAM 

The first step in the design process should be the development, with active 
participation of the owner, of a set of clear performance objectives that address 
how the building is expected to perform before, during, and following an 
earthquake.  These performance objectives should be based on owner needs 
and decisions, and should be expanded into detailed performance statements 
that apply to every subsystem of the building. Throughout the design 
development, there should be explicit reviews of each element of the design 
against the performance statements in order to assure that the completed 
building meets the expectations articulated in the original performance 
objectives. In addition, the owner should be encouraged to develop and carry 
out a risk management plan compatible with the performance objectives. 
The term "performance objective," discussed in Chapters 2 and 4, should 
include a statement regarding the seismic performance that is expected of the 
building, subsystem, or component that is being addressed. Wherever 
possible, it should include quantifiable performance criteria that can be 
measured.  For example, an objective may be that a subsystem (such as the 
HVAC system) should be operable following an earthquake of a certain 
magnitude.  The specific criteria related to this may specify how long the 
system is expected to operate, under what operating conditions, and with what 
resulting interior environmental conditions. 



12.3 ENGINEERING SERVICES FOR ADDED VALUE OF RISK MANAGEMENT 

The owner should establish a process in which the risk management function 
and the facilities management function are fully coordinated 
facility-related risks.  In order to do so, the risk manager should have an 
understanding of seismic risks.  Once the risk manager gains such an 
understanding, the risk manager should be educated to prepare a return-on-
investment analysis for investments in seismic performance. The design team 
has an opportunity to offer the owner a service of educating the risk manager 
on the details of seismic risk in buildings.  This service could be independent 
of any specific capital improvement or design project, or it can be offered as a 
pre-design orientation activity that is linked to a design project. 
Issues of building performance should be communicated to a building owner 
in terms that relate how the building is expected to perform following an 
earthquake, and the potential impacts that this level of performance may have 
on the postearthquake functionality of the building. In order to accomplish this, 
the design team must learn to communicate using terminology that is familiar 
to the owner. This can best be accomplished through interaction with the 
owner's facilities or risk manager. 

It is typically more difficult to explain earthquake risk issues to a building 
owner, 
since such considerations are probabilistic in nature, and less specific with 
respect to magnitude, location, or even how often they will occur.  The design 
team must understand the owner's extent of risk aversion or risk tolerance. The 
more risk neutral the owner is, the simpler the communication is likely to be, in 
that various outcomes can be multiplied by their respective probabilities and 
then communicated directly to the owner. This process, however, becomes 
more complicated with a more risk averse or tolerant owner.  The best way this 
communication can be accomplished is through close interaction and 
coordination with the owner's risk or facilities manager. 

As the member of the design team who initiates the design concept and 
develops it through design development and the preparation of construction 
documentation, the architect should play a key role in the seismic design 
process.  To ensure that consideration of seismic issues occurs with the right 
degree of priority, and at the right time in the design process, the architect 
should have a clear conceptual understanding of seismic design issues that 
impact the design. 

The structural engineer's role is to provide the structural design for a building.  
While the structural engineer must play the major role in providing an 
earthquake-resistant design, the overall design responsibility is shared 
between the architect and engineer, because of architectural decisions that 
may impact the effectiveness of the engineer's design solution and hence the 
building's seismic performance.  The use of per-formance-based design can 
reinforce the importance of the recommendation that the architect and 
structural engineer work together from the inception of a design project, and to 
discuss seismic issues before and during the conceptual design stage.  Many 
of the critical architectural decisions occur at the conceptual design stage, at 
which point the building configuration is set and issues such as the nature of 
the structure and structural materials and architectural finishes are identified. 
The concept of structural engineers participating with architects during the early 
conceptual design phase of a project is not new, yet it is often confined to a 
cursory conversation or does not occur at all, for a variety of economic, 
cultural, 
and professional reasons.  Developmental projects often require a partial 
design in order to procure project financing; at this point, the owner typically 
attempts to minimize upfront costs and the architect will not involve, or only 
peripherally involve, structural consultants.  Some architects see the structural 
engi-neer as providing a purely service role in enabling the architect to achieve 
the forms and spaces that are desired.  In a successful project, the architect 
and structural engineer typically collaborate on layout and design issues from 
the inception of the project, in order to ensure that the architectural and 
structural objectives are achieved. 

As the servicing needs of contemporary buildings continue to increase, the 
impact of the MEP (mechanical, electrical, and plumbing systems) consultant's 
work on seismic design becomes increasingly important. An example of this is 
the need for penetrations or blockouts in the structure to 
gration of the structural and mechanical system, and their size and location 
should be carefully worked out between the architect, structural, and 
mechanical engineers.  There are many instance of damage to buildings in 
earthquakes caused by structural member penetrations that have not been 
adequately coordinated with the structural design. 

design of mechanical equipment supports the responsibility of the equipment 
vendor, the mechanical engineer, or the structural engineer?  Similarly, is the 
design of the connections for precast concrete cladding the responsibility of the 
precast element vendor or the building structural engineer? And, is the layout 
and design of bracing for ductwork the responsibility of the mechanical 
contractor or the building structural engineer?  If these responsibilities are not 
called out at the outset of the job, the result will be disputes, extra costs, and 
potentially serious omissions. 


Design-Build and Fast-Track Projects 

Large projects are often "fast-tracked" to some degree, with the construction 
contract separated into a number of bid packages that may be sole-source 
negotiated or competitively bid.  The objective here is to speed the project's 
overall completion, but the process can substantially complicate coordination 
of tasks.  Among the reasons for this are the following. 

      	The complete design team may not be in existence before the 
preparation of construction documents has begun.  This arrangement can 
create problems when decisions early in the project determine design 
approaches and delegate responsibility to entities who are not yet under 
contract, or who have had no input into such early decisions. 

      	Communication among designers during fast-track projects is usually 
more difficult because the development of separate bidding packages means 
that the design process is fragmented, rather than one which undergoes 
continuous evolution.  At any stage during design development and contract 
document preparation stages of a project, a complete set of drawings of the 
project may not exist. 

      	Because of demands in the project schedule, the design and fabrication, 
or preparation of shop drawings, many items are not always thoroughly 
reviewed by the architect or engineer, and in some cases projects and for design 
teams that have a track record in working together, but 
for more complex projects and for design teams that have not previously 
worked together, both the design and construction phases of a project will 
need special attention.  The assignment of roles and responsibilities is critical 
if the performance objectives are to be adequately defined and for integrated 
seismic design and construction to be achieved. 



Checklists to Facilitate the Design and Construction Process 

A useful aid for the development of performance objectives and the 
coordination of the design and construction process within the design team is 
the use of checklists.  These may be maintained by hand for smaller jobs, or 
computerized for larger or more complicated ones.  Checklists can highlight 
key seismic design issues that require consideration and resolution, and can 
serve to ensure that all issues are adequately dealt with.  The checklists 
discussed below are suggested as models that may be modified to suit the 
nature of the design team and the construction delivery process. 

Figure 12-1 provides a seismic performance checklist, intended to focus the 
building owner and the design team on issues related to seismic performance 
expectations.  The checklist presents a set of questions that are used to help 
the client focus on available seismic performance alternatives, leading to a 
recorded statement of the client's expectations of seismic performance goals 
that, hopefully, are in line with available resources.  Agreement on such goals 
and expectations forms the beginning of a performance-based design 
procedure and can limit future "surprises" due to unanticipated earthquake 
damage.  The checklist statements can become a part of the project's building 
program, in a manner similar to statements about acoustical or thermal 
performance, and can serve as the basis for the use of more formal 
performance-based design procedures during the design. 

Figure 12-2 provides a checklist intended to facilitate a discussion between the 
architect and the structural engineer on the importance of various building 
siting, layout, and design issues.  The checklist identifies a number of issues 
that should be discussed and resolved by the architect and structural engineer 
at the early stages of a new project. The checklist should be used when a 
conceptual design has been prepared and transmitted to the structural 
engineer.  The checklist is intended primarily to provoke a discussion, and is 
not intended to be filled in and used as a document of record.  Most of the 
items in the checklist will need varying levels of discussion; the checklist is 
only 
intended to identify the existence of a potential problem and indicate the 
importance and priority, or significance, of the problem. 
Figure 12-2 also ensures that all significant issues are covered, and that the 
architect and structural engineer have reached mutual understanding on the 
resolution of problems.  This is the point at which the structural engineer 
should explain any issues that are not clear.  Similarly, if planning or other 
constraints appear to have resulted in a questionable seismic configuration or 
a building with other undesirable seismic characteristics, the use of this 
checklist will ensure the identification of these characteristics fairly early in 
the 
design process, and should open the way to their resolution. 

Figure 12-3 provides a list of structural and nonstructural components which 
are typically included in a building project.  It is intended to define the 
responsibilities within the design team for various aspects of the design, and 
establishes the scope of work among the major consultants and suppliers.  
The checklist provides the basis for consultant agreements between the 
architect, construction manager, and specialist consultants.  In most projects, 
costs and a competitive market tend to limit the time and money available for 
design.  Working within a limited budget and timeframe, current practice is for 
architects and structural engineers to leave some design tasks to engineers 
employed by subcontractors and vendors (e.g., the design of precast concrete 
panels and their connections, prefabricated stairs, and truss assemblies). This 
checklist can be used to identify where and when these procedures will be 
used. 

Figure 12-4 provides an example that shows how the checklist in Figure 12-3 
may be completed for a representative project. This example shows a 
traditional design and construction process in which the architect plays the key 
role in design management and project coordination.  The assigned 
responsibilities would vary depending on the nature of the project, the 
composition of the project team, and the proposed design and construction 
procedures. 

Figure 12-5 provides a list of typical building non-structural components and, 
similar to Figure 12-2, is intended to delineate the roles and responsibilities of 
design team members for the design and installation of nonstructural 
components and systems.  In current practice, this area is often unclear and 
important non-structural protective measures may become the subject of 
dispute; in some extreme cases, they may be omitted altogether.  Both this 
checklist and that shown in Figure 12-2 are expected to play an important role 
in establishing the total scope of work for the various project consultants, and 
in ensuring that important tasks do not fall between the cracks of the various 
involved design and construction parties. 



12.5 DESIGN AND CONSTRUCTION QUALITY ASSURANCE 

Building codes require that "special inspections" be carried out for specific 
critical elements of a building during construction.  These inspections are 
intended to assure that a high degree of quality has been achieved in 
constructing the approved design, and in the manner in which it is intended.  As 
related to seismic design, special inspections typically apply to important 
construction and fabrication considerations, such as ensuring the use of pre-
certified weld procedures and adequate weld quality. 

Performance-based seismic design also requires specific performance from 
nonstructural systems and components in the building.  In order to obtain the 
intended seismic performance in these areas, additional quality assurance 
activities are needed, above and beyond those typically required by code or 
employed on normal non-seismic construction projects. The following is a 
partial list of some nonstructural system components in need of special 
consideration or inspection. 


Inspection of the anchorage and bracing of architectural and 
mechanical elements.

Labeling of fenestration products to ensure that they have been pro-
vided as specified, and inspection to ensure proper installation.

Inspection of ceiling and partition attachments. 

Inspection of special equipment. 

The report, ATC-48, Built to Resist Earthquakes: The Path to Quality Seismic 
Design and Construction (ATC/SEAOC, 1999), provides comprehensive guidance on 
issues pertaining to the quality design and construction of wood-frame, concrete, 
and masonry buildings, and anchorage and bracing of non-structural 
components.