Building the Digital World – Architectural Design Methods Based on the Use of Digital Tools – Performance Based Form Generation and Optimization
Ph.D.Thesis, 2008 (together w/ Yezioro Abraham)
ABSTRACT:
There has already
been one loss of innocence in the recent history of
design; the discovery of machine tools to replace hand craftsmen
… now we are
at a second watershed. This time the loss of innocence is intellectual
rather
than mechanical. (Christopher Alexander, 1964)
The introduction of computers to architectural design has
been making a
significant impact on the way buildings are being designed and built.
For the
second time in the history of modern design, technology is advancing
faster
than the building industry. This time, the digital and information
technology (IT)
revolutions introduced technologies that allowed for the development of
architectural designs and manufacturing tools on grounds other than
need, and
thus their influence on architecture
is still largely unknown. This research examines changes in
the
architectural design process caused by the introduction of computers
focusing
mainly on computer-based form generation, simulation and evaluation. It
suggests a new generative performance oriented design (GenPOD) model
that use “performance
envelopes” in a non linear generative design method.
As a preliminary stage a digital architecture database was
developed. The
database, which included projects that followed a new definition for
digital
architecture or computer-oriented design, has shown trends in computer
oriented
design project types, costs, geographical distribution and other
details starting
from the mid 1990’s.
Following the preliminary stage the research focuses on
developments in
architectural design tools/software, design methods and computer-based
generation, simulation and evaluation tools and approaches. It
discusses the
increase in level of control that architects have over the designed
architectural
form, which is based on the increase of the amount of data the
architectural
form embeds, and its implications on the architectural design process.
It also
discusses, via a division into form- and performance based design, the
shift
towards performance-based architectural design, which introduced new
possibilities in terms of using computers in the design process. The
new possibilities
derive, among other, from the ability to embed/add empirical
quantitative data
to the geometrical information regarding the architectural form and
negotiate
quantitative and qualitative data in the generation and evaluation
processes of
the initial architectural design.
Based on these analyses the research introduced the notion
of multiple
performance envelopes as a base for the GenPOD model. Performance
envelopes are
surfaces that connect points with similar information regarding
performance (E.g.
wind performance envelope will be defined by all the points in the
design space
with a similar wind speed). As opposed to traditional approaches in
which computer
simulation is used in an "after the fact" manner in order to evaluate
architectural form fulfillment of certain performative demands, the new
model
suggests to use performance envelopes in a generative, “before
the fact”
approach.
The suggested model allows generating architectural initial
form using a
negotiation process of one or more performance envelopes that stand for
similar
or different performances, regarding different aspects of the design.
The generation
process is parametric and iterative in a sense that it allows to
combine
numerous rounds of generation using different performance envelopes
that influence
the entire form or only parts of the form according to programmatic
demands and/or
designer’s preferences. The model generates in every run several
design
alternatives. The generated alternatives are evaluated in a new type of
evaluation
model that utilizes numerous fitness criteria, not necessarily used for
the
generation of the envelopes. These fitness criteria represent another
layer of
information (besides performance) that the designer receives of the
generated
form.
In order to select the most fitted solution each criterion
is given a
normalized priority by the designer.
A total grade is then calculated for each design
alternative. Both
generation and evaluation process are parametric implying that it is
possible
to change the number and types of performance envelopes
at any stage of the process and examine the effect of these
changes
immediately on the design alternative. It also implies that the
designer can
alter the preference regarding the priorities of the fitness criteria
and thus
examine changes in the total fitness grade.
The GenPOD model was tested in a case study that examines
the
applicability of the suggested method in a design of initial form for
an office
building. The research shows that designing with performance envelopes
increases
the general performance of the building form by increasing the amount
of
performance oriented information from which the buildings’ form
is generated
while allowing to generate an architectural form that embeds a
combination of
user preference with empiric performance information. Moreover, since
the
initial form is generated using performance envelopes it adheres by
definition
to the performances that were used to generate it and does not
necessitate an "after
the fact" evaluation process, hence, guaranteeing the desired
performance
of the proposed building.
Performance-oriented design approaches and the use of models
such as
GenPOD in architectural design are an important step toward a more
efficient
and sustainable environment.
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