June 2006
313.1 Structural Bays: Incremental bay lengths between 40'-6" and 58'-6" are suggested,
with standard 22'-6" width. Many applications have departed from these recommendations in fa-
vor of shorter and/or square bays. For steel structures, longer bays also present additional
challenges for seismic design, due to a limited number of configurations of the lateral force re-
sisting system appropriate for use with long spans. Furthermore, the structural flexibility of such
systems may lead to much heavier and deeper structural elements than anticipated due to drift
limits. Bay sizes need to be coordinated with functional program and space types.
313.2 Floor-to-Floor Height: As shown in the examples in Appendix A, floor-to-floor heights
with VAHBS are typically in the range of 18'-8" to 19'-4". These heights will accommodate a fin-
ish ceiling height of 9-feet and the interstitial service zone. For floors with significant quantity of
spaces with ceiling heights greater than 9-feet, consideration should be given to increasing
floor-to-floor height (as seen at Palm Beach). Designers shall note that VA does not classify the
interstitial service zone as an industrial occupancy or workplace for the purpose of determining
egress requirements (including headroom). Refer to supplement for Section 321 for changes to
ceiling and subzone S-7. The sketch in the Red Book does not reflect the S-7 subzone between
the interstitial deck and the ceiling.
313.3 Building Height: The International Building Code has replaced the Uniform Building
Code as the basis of the structural design for VA Hospitals. Height limits for concrete wall sys-
tems still exist. Structurally other systems may be designed to exceed the 160 foot limit. Build-
ings using the VAHBS that are over 4 stories in height will be classified "high-rise" since the
highest occupied level will be above 75-foot height. The design team will need to consider func-
tional, operational, fire protection, and aesthetic issues when determining the appropriateness of
a high rise design.
313.4 Building Width: This section may be disregarded.
313.5.2 Girders: Discussion focuses on 22'-6" span based on "dimensional discipline" of 4'-6"
for bedroom widths. Modules and dimensions may be adjusted as appropriate to the functional
program and structural system selected. This section also refers to 75 and 115 psf live load ar-
eas in the sketch. See discussion of live loads in Section 314.
313.5.3 Beams: Minimum and maximum
beam depths are given. Though beam
depths can be reduced with shorter spans,
deep beams may still be required to limit floor
vibrations. These limits are necessary for oc-
cupancy comfort or functional requirements in
areas such as surgery operating rooms and
other locations with vibration sensitive equip-
ment, e.g., MRI, microscopes.
313.5.4 Structural Slab: Topping slab is
cited as three inches thick. This is consistent
VA Medical Center
with VA Program Guide PG-18-3 Design and
West Los Angeles, CA, 1976
(not VAHBS, used interstitial space)
Construction Procedures, Topic 6. This will
allow for maximum adaptability. Considera-
SUPPLEMENT TO RESEARCH STUDY REPORT
VA HOSPITAL BUILDING SYSTEM
SECTION 4-7
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