Category Archives: Milstein-Rand-Sibley Hall

Mezzanine problems in Cornell’s proposed Fine Arts Library


Links to all my writings and blog posts about Cornell’s proposed Fine Arts Library can be found here.

The Fine Arts Library proposed for Rand Hall at Cornell University has two stories, each with a mezzanine floor, for a total of four levels all linked by a single continuous vertical opening. Vertical openings in buildings are—with some important exceptions—prohibited by Building Codes because they present a serious fire and smoke hazard if not properly designed or protected by a continuous and fire-rated shaft enclosure. The most common exception to the general prohibition of vertical openings states that any two stories may have a vertical opening between them. This much is clear. However, when mezzanines are introduced, things get more complicated and additional exceptions to the general prohibition against vertical openings must be analyzed.

The 2003 and 2007 versions of the New York State Building Codes—the first that were based on the International Building Code (IBC)—state in Section 505.1 that: “A mezzanine… shall be considered a portion of the floor below.” This is important because the exception allowing two-story vertical openings (in Section 707.2 of the 2010 NY State Code or Section 712.1.9 of the 2015 NY State Code, for example) specifically allows such openings to connect two stories, but only as long as they also are separated from other floor openings. Because mezzanines were previously defined as being part of the floor below, they were not considered as separate floors, and therefore didn’t count as additional floor openings under the terms of this exception. In other words, the four interconnected floors in the Fine Arts Library proposal might have been acceptable under these older Codes (assuming that all other requirements governing maximum mezzanine size were satisfied). However, in all subsequent versions of the New York State Building Code, including those from 2010 through 2015, a single word in Section 505.1 (or 505.2 in later versions) was changed, so that a mezzanine is now considered a portion—not of the floor below—but of the story below.

With this seemingly innocent change—from floor to story—the exception in Section 707.2 of the 2010 Code (or Section 712.1.9 of the 2015 Code) allowing floor openings connecting no more than two stories as long as they are also separated from other floor openings now has a very different meaning. With mezzanine floors no longer included as part of the floor below, but still considered as independent floors, the requirement that any vertical opening linking two stories be separated from any other floors is no longer satisfied if mezzanines are present. It is no longer possible to ignore the mezzanine floor levels by claiming that they are part of the floors below them.

There are only two other potentially viable options for designing “vertical openings” for a new Fine Arts Library in Rand Hall, per Section 712.1 in the 2015 NY State Building Code. The first such option—having a vertical opening between a mezzanine and the floor below—clearly doesn’t work for the Fine Arts Library proposal, since only a single mezzanine and floor can be linked together using this option. The only other viable strategy is to design the vertical opening as an atrium.

Schematic section through the Fine Arts Library in Rand Hall showing the two “stories” and two mezzanine floors proposed in both the schematic design and 50% design development drawings  with the noncompliant “vertical opening” shown in pink (diagram by J. Ochshorn)


Cornell’s proposed Fine Arts Library at 50% design development


UPDATED Feb. 13, 2017 (see comments below).

I’ve been out of the country since August 2016, so I was not able, until now, to examine the 50% Design Development (DD) drawings for the proposed Fine Arts Library that have been made available for viewing in the Dean’s office. This post, therefore, may well be old news. However, having already noted numerous problems with the schematic design proposal, I was curious to see if any or all of them had been resolved. As far as I can tell, the proposal still has many problems, some old and some new. In particular, it appears that the fire wall shown in the schematic plans has been eliminated (replaced with various “fire barriers”) so that the advantages of considering Rand Hall as a separate building (only possible with a fire wall) have apparently been discarded. I’ve sent out an email today with a bunch of questions for the contact person at Cornell Facilities, reprinted below, and will update this post if I get any answers.


1. The Building Department Notes in the 50% DD set list the 2010 NYS Building Code and 2010 NYS Existing Building Code as governing Code documents. Will the drawings be changed to reflect the 2015 NYS Building Code and 2015 NYS Existing Building Code now in effect?

2. There is no comprehensive Code analysis in the 50% DD set that explains the basis of the design. For example, the schematic design proposed a fire wall between Milstein Hall and Rand Hall, allowing Rand Hall to be considered as a separate building. There is no fire wall shown in the 50% DD set (except for “mobile fire wall” notations on one of the elevations — see Question #6 below); therefore Rand-Milstein-Sibley Hall must be considered as a single building with a single construction type. This construction type is V-B, based on the 3rd-floor wooden wall construction of Sibley Hall, and not II-B as noted in the DD set.

A Code variance granted in November, 2013 acknowledges the fact that the existing library as designed and constructed on the third floor of Rand Hall (or a proposed, but not yet designed, library on the second and third floors of Rand Hall) would be noncompliant under the 2010 NYS Building Code, and requests that two specific 2010 Code sections be waived. As a result of the variance hearing, certain requirements in Sections 503.1 and 504.2 of the 2010 NYS Building Code were waived, allowing an increase in the allowable floor area of the second floor from about 22,500 square feet to 70,000 square feet and permitting the library to exceed the second-story limit stipulated in the Code (based on its V-B construction type and A-3 occupancy class) and to occupy the third floor of the “Rand Hall” portion of the combined building. A third Code section waiver, not originally requested by Cornell but suggested by the Hearing Board, waives portions of Section 715.1 of the 2010 NYS Building Code so that the requirement for opening protectives (for the windows that penetrate the fire barriers between Milstein, Rand, and Sibley Halls) no longer needs to be applied in considering the Code compliance of the existing library.

This variance clearly allows the current third-floor library to remain in Rand Hall. It does not, however, change the construction type of the combined buildings from V-B to II-B. It should be emphasized that without a fire wall, Rand Hall is not a separate building, even with the variance, and its construction type remains V-B.

On what basis is the construction type for this project listed as II-B?

3. A Code variance specifies what can be constructed, not merely by enumerating practices that are deemed allowable for a particular project, but rather by waiving specific Code sections that would otherwise render the construction noncompliant. The Code variance granted Cornell in November 2013 waives three Code sections in the 2010 NYS Building Code, allowing the current third-floor library to remain. However, those Code sections are no longer applicable to new construction or renovation, since a new 2015 Building Code has taken effect. The variance granted in 2013 for the current library did not waive any Code sections in the 2015 NYS Building Code. Do you believe that a new library built under the 2015 NYS Building Code (and 2015 NYS Existing Building Code) can waive floor area, story height limits, and window protective requirements in the new Code on the basis of a waiver of three Code sections that were granted with respect to the existing library under the 2010 Building Code?

4. Since the building construction type of V-B is neither Type I or Type II, the maximum aggregate area of a mezzanine is 1/3 of the floor area of the room in which it is located. On the basis of what Sections in the 2015 NYS Building Code can the mezzanines shown in the 50% DD set exceed this 1/3 floor area limit?

5. Section 712.1.9 (Two-story openings) of the 2015 New York State Building Code requires that all floor openings must be “separated from floor openings and air transfer openings serving other floors by construction conforming to required shaft enclosures.” Mezzanines, while not counted as “stories,” are still counted as “floors”; therefore openings connecting any more than two such floors are not permitted unless protected by a shaft enclosure, or designed as atriums. How are floor openings connecting all four floors (not stories) in the Fine Arts Library permitted under the 2015 Building Code?

6. There are two notations on the West Elevation in the 50% DD set that say something like “mobile fire wall” (the font is so small that, even with my reading glasses on, I can’t make out the exact words) and point to the north-west and south-west corners of Rand Hall. What do these notations mean? What is a “mobile fire wall”?

7. A sectional drawing in the 50% DD set shows a dimension of 2’-3” below the hanging 2nd-floor stack area, but seems to show protruding objects on the south side of this hanging floor that are higher than 2’-3” and therefore in violation of the 2015 NYS Building Code and ADA. Can you explain what these protruding objects are (see sketch below) and why you believe that they are Code-compliant?

UPDATE Feb. 13, 2017: I received a brief email response from the Project Manager/Sr. Engineer at Cornell Facilities: “Thanks very much for your thoughts and input and I will forward your email to our design team.  It appears that you are reviewing a 50% DD set, which has evolved considerably.  Once the DD phase is complete there will be new drawings that may address many of your questions.” In other words, it looks like I won’t have any definitive answers to these questions until the 100% Design Development drawings are released.

Links to all my writings and posts concerning the Fine Arts Library proposal can be found here.

Koolhaas delivers “junk-space” to Cornell, in his own words…


“There are no walls, only partitions, shimmering membranes frequently covered in mirror or gold.”


“Structure groans invisibly underneath decoration, or worse, has become ornamental…”


“…huge beams deliver cyclopic burdens to unsuspecting destinations…”

Rem Koolhaas, “junk-space,” Brendan McGetrick, ed., Content, Taschen (Köln, London, etc., 2004), p. 163. Images are of Milstein Hall, Cornell University, designed by OMA.

Exit signs in E. Sibley Hall at Cornell


Exit signs are supposed to clearly show you the way out of a building. The Building Code of New York State puts it this way: “Where required: …The path of egress travel to exits and within exits shall be clearly marked by readily visible exit signs to clearly indicate the direction of egress travel in cases where the exit or the path of egress travel is not immediately visible to the occupants…” With all the best intentions, Cornell University replaced some old and ordinary doors and walls within the main egress stairwell of its architecture building (E. Sibley Hall) with fire-rated glazing and installed a bunch of illuminated exit signs to show the way out.

Views of exit signs from inside the E. Sibley Hall egress stair

Views of exit signs from inside the E. Sibley Hall egress stair

Unfortunately, as can be seen in these recent photos, the transparency of the doors and walls violates the spirit, if not the letter, of the Code. This happens because as one reaches the second floor in the stair (image “b” on the right), one sees an exit sign apparently pointing to an exit outside the stair, just like the sign that one sees on the first floor (image “a” on the left). However, while the sign on the first floor actually points to the exit discharge, the sign on the second floor points away from the exit discharge. In fact, this second-floor sign in intended to get you into the stair from the outside, not to induce you to leave the stair. However, because people using the stair shaft can now see exit signs outside the stair that were not meant to be seen from within the stair itself, what was a simple path of egress has become confusing and therefore dangerous.

More nonstructural failure in Milstein Hall


Last summer (2015), the plaza behind Milstein Hall at Cornell University, along with the concrete fascia over the spaces that sit beneath the plaza, were cut up and put back together again. As I explain in the video embedded below (and on my Critique of Milstein Hall website), the concrete plaza was designed and constructed with no slope and no drain, in violation of standard design and construction procedures. This resulted in a nasty problem in which water, carrying efflorescent residues from the concrete above, worked its way into the gallery space, and onto both the gallery windows and the windows at the west end of the below-grade corridors. The new work doesn’t fix all the intrinsic problems with the design, but seems to fix enough of them, at least for now.

Sunset over Milstein Hall


“God made the two great lights, the greater light to govern the day… God placed them in the expanse of the heavens to give light on the earth, and to govern the day and the night, and to separate the light from the darkness; and God saw that it was good…”

But not good enough for Milstein Hall: only for this building does the sun set in the east!

Movie trailer for Milstein Hall


I made this “trailer” to introduce a lecture in a class that I teach during the Fall term (Building Technology I: Materials & Methods); the class topic is working drawings, and I’ve been using Milstein Hall at Cornell as a case study.

Of course, the trailer is adapted from the movie version of Ayn Rand’s 1943 novel, The Fountainhead, with Gary Cooper playing architect Howard Roark. For more information on Milstein Hall, designed by OMA/Koolhaas, see my critique and construction videos.

Comments on Ho Fine Arts Library: A Body of Books


[Updated below, Oct. 12, 2015 and Jan. 5, 2016]

Better a splendid and complete faculty in a barn than an insufficient faculty in a palace.

— A.D. White

A public relations piece written by Kent Kleinman, Gale and Ira Drukier Dean, AAP, and Anne R. Kenney, Carl A. Kroch University Librarian,* claims that a project to create a new Fine Arts Library in Rand Hall at Cornell University will address “a host of issues critical to the university, the library system, and faculty and students across campus.”

Many of these issues have nothing to do with the essence of the proposed library design itself, but are meant to address longstanding fire safety and environmental problems: “rehabilitating the dilapidated envelope of Rand Hall, dramatically improving the building’s thermal and environmental performance, implementing a number of code upgrades…” It is only the last claim, “reconfiguring the storied former studio spaces of Rand Hall to become a new state-of-the-art research library,” that is more than a bit contentious.

Kleinman and Kenney ask: “What constitutes a state-of-the-art research library for the fine and design arts?” Their answer is: “public computers, shared and private spaces for collaborative and individual study, comfortable furniture, good light, seminar rooms outfitted with large displays for GIS and other data-visualization instruction, infrastructure for remote learning, workstations compatible with computers, phones, and tablets.” Also, they mention that such a library will have “extraordinary librarians, trained in the most current digital technologies to help our students manage digital images and navigate online resources” (but they fail to note that none of these Fine Arts librarians were asked to serve on the Fine Arts Library Building Committee). Let’s examine these state-of-the-art features.

First, “public computers” have been in libraries for decades and represent neither “state-of-the-art” design, nor even a necessary feature at a university facility where students and faculty already have their own portable internet-connected devices.  Second, “shared and private spaces for collaborative and individual study” is merely jargon that bears no relationship to the actual “spaces” shown in the schematic design plans. In fact, there are no private spaces in the library, but only round tables and chairs placed in the most public of all locations. Being public, all of these spaces are by definition “shared,” but none can facilitate meaningful collaboration. Collaboration requires a degree of visual and acoustic privacy, neither of which exists in the proposed library. There are two seminar rooms shown in the plans (more on that later), but such classrooms should not be confused with private or collaborative spaces. Third, “comfortable furniture” and “good light” may be desirable, but should not be placed on a list of qualities that define “state-of-the-art” research facilities. Fourth, seminar rooms are just classrooms. Of the two shown in the schematic design proposal, one is just a room that already exists in Rand Hall; the other seems to be a glass box at the end of the top stack level, cantilevered over the building’s east facade. Classrooms are great (assuming they are designed properly; i.e., not as glass viewing platforms), but they have nothing to do with the functionality of a university library.

So much for the “state-of-the-art” design. The truth is that a state-of-the-art research library is an elusive concept, and no one can claim to anticipate how collections of books, images, or other resources will be searched and accessed in five, ten, or twenty years. But two points should be emphasized. On the one hand, all of the constituent ingredients for a research library that were listed by Kleinman and Kenney (computers, furniture, etc.) can easily be accommodated in the existing Rand Hall spaces without demolishing and reconfiguring much of the building at great expense, as is proposed. On the other hand, the current “low-value” industrial space of Rand Hall is ideally suited for adaptation to an unknown future, for reasons I have discussed elsewhere (scroll down to fig. 6). The current proposal creates a “high-value” design object that cannot be anything other than what has been designed for in 2015. In other words, it is not only dysfunctional as designed, having no private or semi-private collaborative spaces, but it points to an imagined and caricatured past, not to a rapidly transforming future.

Kleinman and Kenney probably understand that their arguments for a “state-of-the-art” facility are entirely specious, since they quickly try another tack, suggesting that since “the most state-of-the-art component of our new facility… is only newest and latest for the briefest moment,” there must be something else that can justify the destruction and reconstruction of a useful industrial building at great expense. Their new argument? It’s all about the books! “The protagonist of the new facility will be an open stack, circulating collection of books covering urban design and planning, architecture, fine arts, art history, landscape architecture, and interior design. Stable, immune from software glitches, with reliable color rendition and faithful text/image relationships, unchanging aspect ratios, and always fully charged. They never crash, even if 1,000 students each have 20 open at the same time.”

[Updated later on Oct. 12, 2015: Speaking of physical objects being “stable” and “immune from software glitches,” etc., the famous archive (AKA “morgue”) of the New York Times was almost destroyed two days ago: “A broken pipe on Saturday morning sent water cascading into the morgue — the storage area where The Times keeps its immense collection of historical photos, along with newspaper clippings, microfilm records, books and other archival material — causing minor damage and raising significant alarm. And it raised the question of how in the digital age — and in the prohibitive Midtown Manhattan real estate market — can some of the company’s most precious physical assets and intellectual property be safely and reasonably stored?”]

Needless to say, the current Fine Arts Library on the third floor of Rand Hall already has books. If one wanted to put more books in Rand Hall, rather than leave the less active portion of the collection in the library annex as it is now, one could expand the library into the second floor of Rand Hall. The combined second and third floors of Rand Hall, as they currently exist, have about the same floor area as the proposed library would have and could accommodate about the same number of books, chairs, tables, and seminar rooms, preserving the building’s industrial character and flexibly so that it could more easily adapt to future changes. This point must be emphasized: criticism of the proposed library scheme has nothing to do with some hypothetical debate about the value of books vs. digital media. Nothing in the proposed library scheme does anything for “books” that the existing library doesn’t already do. To suggest some sort of struggle between traditional books and digital access is, in this context, entirely disingenuous.

Kleinman and Kenney’s line of reasoning is flawed for other reasons. Having “books” hardly guarantees access to those books. To the extent that the books are withdrawn by students or faculty, they are no longer available in the stacks and must be recalled—a process that can take weeks. The notion that only physical books can preserve the formatting qualities (aspect ratio) intended by the graphic designer is ludicrous: I am the author of a book whose formatting is tricky and which does not lend itself to reflowed text characteristic of EPUB or kindle devices. Even so, I was able to (finally) find a publisher willing to release the book as both a paperback and a PDF (both of which have identical formats and aspect ratios). The idea that physical books are somehow more reliable than digital versions is just silly. Library books constantly go missing, or become worn out, or have pages ripped out, or get marked up with obnoxious highlighters.

Books are also highly flammable, which is why libraries are categorized as class A-3 occupancies in the Building Code. In fact, the notion that Cornell wants to safely preserve this “stable” resource is entirely hypocritical: Dean Kleinman was an enthusiastic proponent of placing the Fine Arts Library on the third floor of Rand Hall after Rand was connected to Sibley Hall by the construction of Milstein Hall. I advised Dean Kleinman when this plan was proposed that such a move was unsafe and illegal because placing books on the third floor of what is now a combined building with type V-B construction is noncompliant and creates a fire hazard. When my formal complaint was upheld by a Regional Code Review Board, Cornell still had no interest in fixing the problem, but instead asked for a Code variance (which was ultimately granted) so that the books could remain in this compromised location.

The schematic design proposal prepared by Wolfgang Tschapeller (M.Arch. ’87) actually contains numerous Building Code violations, so that Kleinman and Kenney’s claim that this scheme would implement “a number of code upgrades” is rather ironic. The four most egregious violations, which I pointed out in blog posts here and here are as follows: (1) a 2-hour fire wall was proposed whereas a 3-hour fire wall is required; (2) the various interconnected stories and mezzanine floors violate fire safety requirements since they are not protected by shaft enclosures; (3) the so-called mezzanine floors are too big; and (4) the bottom book stack floor hovers over the second-floor space as a long “protruding object” that violates both the Building Code and the Americans with Disabilities Act (ADA).

Kleinman and Kenney state, implausibly, that physical books are valuable because of their “reliable color rendition.” In fact, authors are constantly running into issues with the quality, or even the possibility, of high-quality reproduction of images in physical books because of the enormous expense that high-quality color print reproduction entails. It is not unheard of, especially with academic presses, for authors to scrounge around for additional funds to give to their publishers if they want a few images reproduced in color. For institutions that are truly interested in creating a useful archive of images, the only rational strategy is to digitize the collection. Even Cornell’s own Johnson Museum has done just that: “Cornell’s art repository includes paintings, prints, sculptures, and published graphical images (woodcuts, etc.). By putting the collection on-line, students, faculty, visitors, and users on the Internet will be able to electronically explore and research the collection from their home, office, or one of the workstations in the museum. Users can learn about artists and their works, and use Insight tools to view high quality images and groups of images.”

As opposed to this useful and progressive dissemination strategy, Kleinman and Kenney quote Tschapeller, the proposal’s architect, who suggests instead that we literally walk up “winding staircases [which] are the keys to enter this volume of knowledge, browse, read, and wonder.” Not content to go back to rows of wooden card catalogs, these architects of the twenty-first-century library want to dispense with logical processes altogether and instead use “winding staircases” to enter some sort of metaphorical “volume of knowledge.”

Since the absurdity of this argument is readily apparent, Kleinman and Kenney again retrace their steps by offering a contradictory rationale, stating that they aren’t actually motivated by “technophobia” or “nostalgia.” What then is the reason for demolishing the third floor and roof structure of Rand Hall, constructing new transfer girders above the current roof level, reinforcing the now-unbraced exterior walls with new columns, underpinning the existing foundations to respond to the new loads, hanging stack levels from the transfer girders, and building a new elevator for these stack levels (since the elevator that was finally placed in Rand Hall as part of the Milstein Hall project is now inaccessible to the proposed hanging stacks)? Kleinman and Kenney’s answer is that students and faculty in the College of Architecture, Art, and Planning use books and love libraries. What they fail to mention is that all of the statistics that they have gathered are based on use of the current facility. None of the “facts” that they have assembled (e.g., that a greater percentage of assistant professors check out books, compared to associate or full professors; or that “88% of AAP students credited the library as contributing to their academic success”) has any bearing on the question of whether or how to renovate or expand the current library facility. In the first instance, the cited statistics only show that assistant professors, under greater pressure than senior faculty to produce scholarship in order to be reappointed or promoted, may well be more inclined to use current library resources. In the second instance, the statistics show that the current facilities seem perfectly adequate to at least 88% of our students. There is nothing in these “facts” that supports the current Fine Arts Library proposal; they do, however, provide some evidence that the existing library facilities are working fairly well as is.

But there are still more irrelevant arguments, again attacking the digital straw man (“…a good portion of our printed materials is not online… Fine arts books are characterized by images, and images—protected by use and copyright laws—are expensive to acquire and require specialized skill to reproduce. …this results in many fine art volumes having their images redacted or watermarked… the veracity of the reproduction is often marred by poorly managed input and output variables affecting key attributes of an image’s content… Images are primary content, the language of our disciplines.”) Two separate issues are being conflated here: first, that much of the content of books is intellectual property and therefore subject to the exclusive control of the copyright owner, except for limited “fair use” exceptions. In this respect, there is absolutely no difference between print and digital content. Libraries pay lots of money for all forms of intellectual property, whether physical books or electronic documents. The second issue is whether Cornell should destroy a useful and flexible low-value industrial building to create a new library, when the current library (or a modest renovation to expand it) would accomplish the same goals while preserving the flexibility inherent in the current building design that is certain to prove useful in the future, as the role of libraries changes in unexpected and unknowable ways.

[Updated Jan. 5, 2016: While Dean Kleinman insists on the importance of physical books, his own Fine Arts Library staff are urging faculty to use digital material for their course reserves. Here is an excerpt from an email just received from the Circulation/Reserve/Billing Supervisor for the Fine Arts Library at Cornell: “We have found that the electronic reserves (ie: book chapters, articles, e-books,  and streaming films) showed a much greater level of usage than physical items at the libraries.  If you utilize Blackboard and electronic reserves, we are encouraging faculty and instructors to submit materials which we will gladly scan and upload in order to assist you in providing easier access to the course readings and films” (emphasis in original).]

Kleinman and Kenney feel the need to say more about physical books, even though their hyperbolic sentiments (“… books are like buildings. You enter a book as you would enter an interior space. Your mental movements are choreographed by the geography of the page…” and so on) are not relevant to the question at hand. No one is threatening the books. Nothing in the proposal for a new library does anything to preserve or protect library books that a more modest and rational renovation wouldn’t do equally well, if not better. The reality is that Rand Hall—not its collection of physical books—is being literally threatened by the proposed renovation; all of these scare tactics surrounding the protection of books are nothing but a smokescreen.

Finally, this critique wouldn’t be complete without referencing the recent inaugural address by Cornell’s president Elizabeth Garrett, in which she incorporates the prescient comment by Cornell University co-founder A.D. White that I have placed at the top of this blog post:

When A.D. White began to implement his plan for Cornell University, his highest priority was hiring faculty. “Better a splendid and complete faculty in a barn,” he stated, “than an insufficient faculty in a palace.” The recruitment, development and retention of the best faculty remain our paramount priorities: an exceptional faculty is the bedrock of our teaching, research and creative work, and our public mission. It is the faculty who attract the finest students and inspire them to embark on their own adventures of learning. It is the faculty who seek to discover new knowledge, move us forward in our search for truth, and apply what they have discovered in ways that improve well-being around the globe. It is the faculty whom our alumni remember when they speak of their years at Cornell. It is the faculty, as well as our students, whose work inspires our dedicated staff to ensure that all aspects of our environment are conducive to our educational mission.

* Anne Kenney’s name is listed first in the cited article but this piece is so clearly marked by Dean Kleinman’s intellectual fingerprints that I have reversed the order of their names.

More writings on the Fine Arts Library proposal.

Rand Hall’s East Stair Tower


I’ve written a piece called “What’s Wrong with Rand Hall’s East Stair Tower” that was originally intended as a photo supplement to my blog post on the Cornell University Fine Arts Library proposal’s “Site Narrative,” but got expanded a bit to include a short historical overview of the site.

In this photo from 1909, taken about three years before Rand Hall was completed in 1912, one can see the types of informal and functional engineering structures built along University Avenue behind the stone Arts Quad buildings at Cornell University (image from Ithaca then & now by Merrill Hesch and Richard Pieper).

In this photo from 1909, taken about three years before Rand Hall was completed in 1912, one can see the types of informal and functional engineering structures built along University Avenue behind the stone Arts Quad buildings at Cornell University (image from Ithaca then & now by Merrill Hesch and Richard Pieper).

More writings on the Fine Arts Library proposal.

Rand Hall’s 1st-floor column capacity


[Updated below: Oct. 26, 2015] The current schematic design proposal for a Fine Arts Library in Cornell University’s Rand Hall calls for hanging multiple levels of book stack floors from new transfer girders spanning from newly-reinforced columns on the building perimeter. But is it really necessary to destroy the building’s interior structure, run new transfer girders at the roof level to the building perimeter (requiring the reinforcement of exterior columns and underpinning of exterior foundations) and hang stack levels from these new roof girders? Can Rand Hall’s existing structure support library stacks on its second and third floors without going to all this expense?

Well, it’s clear that the existing floor structure is adequate for library stack loads, since library stacks have already been placed on the third floor of Rand Hall. It’s also clear that the existing second and third floor columns of Rand Hall are perfectly capable of supporting library stacks, since, on the one hand, the third-floor columns only support the roof and, on the other hand, the second-floor columns are already supporting library stack loads from the third floor.

It’s also clear that the total available floor area for a library on the existing second and third floors of Rand Hall is comparable to the floor area proposed in the schematic design submission, so that the rationale for going to all this trouble has nothing to do with increasing available floor area beyond what is currently existing.

Therefore, the only remaining practical issue that might justify a more elaborate and expensive design scheme, such as the one proposed, is whether the first-floor columns in Rand Hall could actually support the additional loads brought about by having stack areas on both the second and third floors of Rand Hall.

Rand Hall's first-floor column (photo by J. Ochshorn, Aug., 2015)

Rand Hall’s first-floor column (photo by J. Ochshorn, Aug., 2015)

Let’s find out. Disclaimer: I’m not a structural engineer, and the following preliminary calculations should, of course, be checked by a competent professional.

First, some analysis assumptions.

1. We’ll assume typical library stack live loads of 150 psf (the same number used in the proposed Rand Hall library schematic design calculations, and the number commonly found in building codes for stacks no higher than about 7.5 feet) and assume a dead load of 65 psf, which seems reasonable  (this number corresponds to the weight of an average reinforced concrete slab thickness of about 5 inches).

2. We’ll assume steel properties, based on values from 1911, when Rand Hall was constructed, as follows: a yield strength, Fy, of 27.5 ksi and a modulus of elasticity, E, of 29,000 ksi.

3. We’ll use a tributary area for a typical column of 15 x 15.33 = 230 square feet per floor (see typical plan).

Rand Hall 3rd floor plan showing typical column tributary area

Rand Hall 3rd floor plan showing typical column tributary area

4. We’ll compute the radius of gyration for a typical first-floor column by measuring it’s cross-sectional dimensions, computing the moment of inertia about the weak axis, Iy, computing the area, A, and finding r = square root (Iy/A).

Rand Hall typical 1st-floor column cross section

Rand Hall typical 1st-floor column cross section

Iy = (0.375 x 8.56253 / 12) x 2 + (2.625 x 1.06253 /12) x 2 + 4.25 x 0.31253 /12 = 39.77 in4

A = (0.375 x 8.5625) x 2 + (2.625 x 1.0625) x 2 + 4.25 x 0.3125 = 13.33 in2

rmin = square root (Iy / A) = square root (39.77 / 13.33) = 1.73 in.

5. We’ll assume a column height of 14 feet; so that the “nominal” (i.e., not yet accounting for the fact that the column is built-up and riveted) slenderness ratio of the column, KL/r = (1)(14×12)/1.73 = 97.1.

Next, the capacity calculations:

Because this is a built-up, riveted column section, we’ll follow the advice in the AISC Steel Construction Manual (14th edition) for built-up members (p.16.1-37) and replace the slenderness ratio, KL/r, with a modified slenderness ratio, (KL/r)m.

When the maximum distance between rivets, in this case 6 in., divided by the minimum radius of gyration of an individual component, in this case, 0.09 in. for the 5/16 in.-thick by 10 in. wide web plate, that is, 6 / 0.09 = 66.7, is greater than 40, then the modified slenderness ratio used in the capacity calculations, (KL/r)m = the square root of the sum of the squares of the nominal slenderness ratio of the whole cross section and 0.86 times the distance between connectors (i.e., 6 in.) divided by r for the web, i.e, 0.09 in; or the square root of the sum of (97.12) + (0.86 x 6 / 0.09)2 or the square root of (9428 + 3287) = 113.

There are certain dimensional requirements specified as follows: the effective slenderness ratio, Ka/ri for an individual component (in this case, governed by the steel plate web, with the fastener spacing, a = 6 in.) must be no greater than 0.75 x the nominal slenderness ratio of the whole cross section. Since (1)(6)/0.09 = 66.7 < 0.75 x 97.1 = 72.8, the sectional capacity can be based on the modified slenderness ratio found above: 113.

We need to determine whether the column behavior is elastic or inelastic by finding the slenderness ratio, called Cc, that separates these two failure modes: Cc = square root [π2 x E / 0.44Fy] = square root [π2 x 29,000 / (0.44 x 27.5)] = 154, so the column will fail inelastically. The available strength for inelastic column capacity is Fc = 0.658(Fy/Fe) x Fy / 1.67; where Fy = 27.5 ksi and Fe = π2 x E / (KL/r)m2 = π2 x 29,000 / (1132) = 22.42. Therefore:

Fc = 0.658(27.5/22.42) x 27.5 / 1.67 = 10.35 ksi.

Since the column cross-sectional area, A = 13.33 in2, the (safe) capacity of a typical first-floor column = Fc x A = 10.35 x 13.33 = 138 kips.

Finally, the maximum load acting on the first floor column is found by multiplying the tributary area for each floor by the loads acting on that floor, and taking the sum of these products:

Assuming a combined live and dead load of 150 + 65 = 215 psf for the second and third floors, and a combined snow and dead load of 40 + 65 = 105 psf for the roof, and with a tributary area per floor of 230 square feet, we get a total load of 230 x (215 + 215 + 105) = 123,050 pounds = 123 kips. Since this is less than the capacity of the column (138 kips), the Rand Hall first-floor columns are safe with library stack loads on any or all of the floors.

Updated Oct 25, 2015: At a department faculty meeting today, Dean Kent Kleinman clarified that although the steel columns can support the weight of two floors of book stacks, as demonstrated above, the underlying soil can support only one level of stacks (as is presently the case) but not two levels of stacks. According to this reasoning, the foundations would need to be somehow reinforced even for a simpler library renovation on floors two and three. However, there are other options. 1) A two-story library could be placed on the first and second floors of Rand Hall which would only put one level of stack loads on the column foundations (since there is no basement in this part of Rand Hall, one level of stacks would be supported directly on the slab-on-ground); this would allow the shop to be placed on the third floor, making exhaust ventilation easier (directly through the roof), and allowing the articulation of the existing Rand Hall facade to more clearly represent its internal functions (figure 1). This scheme also has the advantage of not requiring the shop to move to the Foundry space for more than one year, as is currently planned. The phasing of the library in its renovated spaces would also be easier to accomplish.   2) A two-story library could still be placed on the existing second and third floors, with desks or other working spaces integrated into the stack area so that overall loading is reduced on the columns.

The existing facade of Rand Hall is articulated as a 2-story base with a 1-story top (photo by J. Ochshorn, July 19, 2012)

Figure 1. The existing facade of Rand Hall is articulated as a 2-story base with a 1-story top (photo by J. Ochshorn, July 19, 2012)

More writings on the Fine Arts Library proposal.