620
Conclusions: Limitations and Constraints
To provide the required lateral bracing, shear walls must extend
continuously downward through the building to the foundations. Allowable
openings are seriously restricted. Exterior shear walls limit fenestration,
and internal shear walls inhibit planning. The system rules and suggested
design configurations are intended to minimize this effect, but it cannot be
altogether eliminated. The cluster of shear walls around stacked service
bays can be particularly troublesome since they tend to form an enclosing
row of towers at the building perimeter. In large horizontal design
configurations, they can also introduce significant internal obstructions to
the planning of efficient circulation patterns and departmental layouts.
However, since the location, size and proportion of the service bays are
only partially predetermined by the Prototype Design, these parameters
can be adjusted within certain limits by the A/E to optimize any particular
configuration.
623.3
REDUNDANCY
In the interests of design and construction simplicity and long-range
adaptability, over-design of certain building components and spaces is
recommended. These include floor load-bearing capacity, size of trunk
ducts and other service mains, size of mechanical and electrical rooms
and service chases, and depth of the service zone above the ceiling.
Other system characteristics imply larger than normal amounts of
materials or space. For example, the rigorous organization of service runs
prohibits typical point-to-point routing, and increased floor-to-floor height
produces taller columns and elevator shafts, more exterior wall, etc. Also,
the use of a limited range of space and service modules adjustable only in
rather sizeable increments of area implies deviations from maximum room
sizes and gross-to-net-area ratios set by current practice or regulations.
This redundancy is considered entirely justified by anticipated benefits, but
nevertheless must be taken into account when the Prototype Design is
compared with conventional design and construction, particularly in terms
of first cost. An analysis of these cost effects is presented in Section
751.3.
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