Considered to be the oldest architecture and engineering firm in continuous practice in the U.S. today, SmithGroup works on a broad range of project types. At Terrell Place in Washington, DC, the firm worked on both residential and commercial spaces. A detailed floor pattern can be found within the building. During the value engineering process, the stone thickness was reduced from 3 cm to 1 cm, and it was installed with a crack isolation membrane to avoid cracking.

Started by Sheldon Smith in 1853, SmithGroup is considered to be the oldest architecture and engineering firm in continuous practice in the U.S. today. The company, which has nine locations throughout the country, recently celebrated its 150th anniversary in 2003.

With 800 employees under the direction of Chairman David R.H. King, FAIA, and President and Chief Executive Officer Carl Roehling, FAIA, SmithGroup has offices in Ann Arbor, MI; Chicago, IL; Detroit, MI; Los Angeles, CA; Madison, WI; Minneapolis, MN; Phoenix, AZ; San Francisco, CA; and Washington, DC. The firm experienced tremendous growth between 1997 and the end of 2000, when its staff size increased by nearly 40%.

SmithGroup designs a broad range of applications in both the U.S. and abroad. Primary markets for the company include: Health, Science & Technology, Learning, Workplace, and Urban Design and Planning. Some recent notable projects that the firm has worked on include the National Museum of the American Indian in Washington, DC, a new 250,000-square-foot museum constructed on the last major un-built site on the National Mall; the Michigan Technological University Center for Integrated Learning and Information Technology (CILIT) in Houghton, MI, a 209,000-square-foot addition including a library and departmental space for computer science, mathematical sciences and physics; and Discovery Communications in Silver Spring, MD, a 500,000-square-foot worldwide corporate headquarters.

Recently,Contemporary Stone & Tile Designhad the opportunity to speak with several members from SmithGroup's Washington, DC, and Detroit, MI, offices. Participants in the roundtable discussion included:
  • Michael Dobbs, AIA, principal; Washington, DC
  • Andrew Rollman, AIA, vice president; Washington, DC
  • Paul Urbanek, AIA, NCARB, vice president; Detroit, MI
CSTD:To begin with, I'd like for everyone to introduce themselves and briefly discuss the kind of work that they do.

Dobbs:I am a principal at SmithGroup. I am currently working on a project for The Smithsonian called the Old Patent Office Building in which two galleries - the National Gallery of Art and the National Portrait Gallery - will be housed. We are enclosing a 28,000-square-foot courtyard in a curved glass and steel roof, and putting in a new 28,000-square-foot granite floor in that space. Just prior to that, I was working on the National Museum of the American Indian, on which I was the project manager and project designer for SmithGroup in a partnership with Jones and Jones of Seattle and Polshek Partnership in New York.

Rollman:I am also a principal and specialize in commercial office buildings and high-rise residential buildings. I also have a background in interiors and educational work and some retail design. Currently, I am a studio leader and head of design for the workplace and residential studio in SmithGroup's Washington, DC, office.

Urbanek:I lead the design in SmithGroup's Detroit office, primarily for research and learning. Some of my recent projects include some small environment projects, one of which is in Indian Springs and uses ashlar limestone. We are also working with the University of Michigan, where we are adding on to a 1946 building with a limestone pit floor.

CSTD:Overall, how often does the firm use stone in its work?

Urbanek:It depends on the types of projects we are doing. We do a lot of institutional projects for higher education, government, and cultural institutions, so we use a fair amount of stone. A lot of our buildings are masonry buildings that might have limestone trim and such on them, but we do have occasion to use a lot more, as we have seen recently. We are presently doing the addition with Michael Graves for the Detroit Institute of Art, which is an all-white Vermont stone building. With institutional buildings, you are trying to build a building that will last for 50 years, and so stone is certainly a material that suits the purpose.

Rollman:I'd say on the commercial side, almost all of our buildings use stone. A lot of our work is in downtown Washington, DC, and Washington is really a white stone city. There is an abundance of Indiana limestone. We typically use natural stone on the base of the building - on the ground floor where the building meets the street - where the pedestrian would really see and touch the building. We frequently use stone on water tables and bases, and then we design some buildings that are all stone. Right now, we are doing a building with the Shakespeare Theater and the International Union of Bricklayers and Allied Craftsworkers in collaboration with Diamond Schmidt of Toronto, and that building is going to be all French limestone. We had initially selected ground face CMU [Concrete Masonry Unit], but the Union said that they want their members to come and see the highest use of the craft, so they want a stone building. In commercial office buildings, we almost always do our interiors in stone - especially the floor.

Dobbs:In my experience here at SmithGroup as well as with prior firms - I've used stone tremendously. The most recent large use of stone was on the National Museum of the American Indian for the Smithsonian. We used approximately $25 million worth of it, including labor. The entire exterior is natural stone - limestone from Minnesota - and that carries into the building as well as on the walls. The toilet rooms have stone floors and countertops. The entire ground floor of the building as well as all of the main landings in the large atrium space and all of the pathways and plazas on the exterior are a black granite called American Mist.

CSTD:Can you take me a little through the process of specifying stone? How does it start? Do you start with the idea of color, or from the beginning do you know that this is the type of building that is going to use stone? And then from there, how does it progress to what you actually use?

Urbanek:The easiest way to answer this question is to talk about a few projects where we've looked at stone, and looked at it in a number of different locations. I can tell you about the LS&A building at the University of Michigan. It's a 1946 brick building done in an International style. It has limestone trim around the windows, the doorframes and such, but it is very much a modernist type of expression - very geometric and crisp. We had to add a penthouse to the roof and a fifth floor. We couldn't match the brick, so we elected to match the stone and build the fifth floor all out of white Indiana limestone. It has a very light feeling, but it is masonry in its fundamentals. Their basic premise at the University of Michigan is that they like the longevity of the masonry. They've had some problems recently with some metal buildings, and they weren't sure that metal was the right approach to take with a building that is 70 years old. So the limestone, and detailing it to meet 2005 design ideas, seemed to fit very well.

On the Indian Springs Environmental Discovery Center, we used stone in a totally different way. We used a ledgerock limestone out of Fon du Lac, WI. It works very nicely as a natural outcropping. We used it with a copper roof, so you get the lightness of the limestone there, which is tan in color, with the darkness of the copper roof. They work in very nice contrast to each other.

Dobbs:For me, the selection of stone usually occurs the way all materials get selected, and that has to do with understanding the concept being developed for the project. The material selection is a supporting effort to the symbology of the building; to what is inspiring to the design of the building - the direction that it is taking. Then there are other occasions where depending on the context - where you are and who your client is - stone gets selected because it is perceived to be a quality level commensurate with how that client perceives themselves. For instance, at a corporate law firm, the lobby is going to use, in all likelihood, what is perceived to be classy, expensive materials and finishes.

Rollman:Once we determine what that stone is - typically color comes up in the very beginning - then we work directly with a stone subcontractor with whom we have developed a relationship. We have two or three that we work with. They will send us samples, or we will go to their shops and look at the slabs that they have. They may do research overseas and get us more samples.

CSTD:So do you have a broker or distributor that you work with?

Rollman:We typically work more with the subcontractor, who is the installer, and they work with their brokers. Occasionally, we use domestic stones, but we tend to use marble and other more exotic stones.

Dobbs:We have a library filled with hundreds of samples already, so you can get the process going without leaving the office.

Urbanek:I have a good friend who is a stone broker and has been in the business for family generations, so I have sort of an “in” when trying to find different kinds of stone when it is required.

CSTD:On certain projects, what separates one company from another when choosing stone? Paul, you had mentioned Indiana limestone, and Michael, you had mentioned Minnesota limestone. Those materials are supplied by more than one company, so how do you choose which one? Is it price, ability or a relationship?

Dobbs:For us [working on the National Museum of the American Indian], we went to the quarries in Mankato. We spent three or four days in Minnesota, and we toured two facilities to see what their capabilities were as well as what the material was. They both are on the same basic vein of stone that runs through that part of the state, but they are far enough apart that the aesthetic qualities of the stone - particularly the color - are a bit different from one to another. That was one deciding factor.

Both of these companies are not only quarriers, but they are also fabricators, and it is not normally that way. Normally, you go to quarry, they just cut out blocks, and then they send it to someone else who cuts them up to create the sizes and shapes that you need.

Mankato Kasota Stone has been around for about 150 years, and when you tour their shop, it looks it. It's wonderful. They have the same old machines that their grandfathers and great-grandfathers had, and they are very proud of that. They are proud that they use the same old craftsmanship and the Old World quality - paying attention to detail and the manual aspects of what they do.

Vetter Stone Co., on the other hand, was started in the 1950s or 1960s, and the brothers that started the firm all had sons, and those sons all went into the business. They invested in the state-of-the-art Italian computer-driven machines.

CSTD:How about in Indiana? I have seen the shops there, and there seems to be that same kind of dichotomy of companies. Some have state-of-the-art equipment and others do a lot of work by hand.

Urbanek:I have noticed in a lot of cases, economics [is a deciding factor]. It is going to go out to bid, and a certain firm is going to get the work in a lot of the university projects. You have to understand that rationale. But also, I think you look at each quarry or each supplier and their ability to deliver consistency; to deliver timeliness; and to deliver the level of detail that is going to be required. If you are putting up stone that has a lot of shaping to it, with each piece numbered and ornately done, there is much more concern about the craftsmen who will be providing that stone. Whereas if you are looking at doing a belt course of the bullnose every 5 feet, you will be a little less critical of the craftsmen who are putting it together; maybe someone who has higher-tech machinery might be a better solution. So, you look at the job and go from there.

CSTD:Andy, you mentioned stone from Italy. When you are working with stone that is being fabricated overseas, how do you monitor or set the quality standards?

Rollman:Our specification is in the beginning, but we really rely on our local relationships. In our projects on the commercial side, we schedule at least two or three trips overseas to monitor the progress. We are trusting the relationship with the subcontractor and the people on the Italian side, and then we are over there for buying the blocks; for looking at each slab; and then for laying out the pattern. So, we are very involved in the process.

CSTD:Do you find that your clients are receptive to learning about new materials, or is it challenging to introduce them to new products?

Urbanek:It is a little bit of both. We are working on another project for the University of Michigan with concrete floors, and the client was not very happy or enlightened to the idea. So what we have done is create a banding in the concrete floor with Sierra White granite from Cold Spring [Granite Co.] with a hand-rubbed finish. We did a simple mock-up with pre-cast concrete and showed them how the banding would work. They have come to take that as their own now. It's their floor, which they agreed to and they made, and now it is a nameplate for the design. So, in some ways, you can educate clients in a way that they can see it become something pretty special.

Rollman:On our Terrell Place project, we did it in a subtle way. The palette in the building was cream-colored and muted. There were two components - a commercial building and a residential building. In the residential building, we used a travertine that wasn't filled, and the finish is sort of rough. It is not a highly polished finish. So it still has a very elegant conservative look, but when you get up to it and really see it and feel it, the texture is very unique and modern.

CSTD:We have talked a little bit about budget and using stone in a cost-effective manner. What are some of the ways in which you are able to do that as architects?

Dobbs:One way is to finish the stone as little as possible. We have gone to such extremes as to use granite boulders as part of the architecture - literally picking them out of the ground and placing them on the construction site. At Vetter's quarry, I believe we showed them a new use for one of their materials that they normally threw away. When they open up a new part of the quarry, they blow off the dirt, the trees and the bushes with dynamite. The first material that is exposed has been saturated for millions of years with water and mineral-rich soils, and it is has a “rusty” appearance. It has incredible iron oxide and stains, and they thought it was sub-grade material that nobody would want. They would slice it off and throw it away. We used it - without touching it - on the base of our building in the largest blocks that they could cut out of the ground. Some of those blocks were 1,500 or 1,600 mm long and about 1 meter high, and in some cases, 400 mm thick, which is 16 inches. These are massive stones that weigh tons.

Urbanek:I've used Fon du Lac limestone probably about half a dozen times now, and Fon du Lac is part of the Niagra Escarpment, which comes out like shale or slate in layers, and the layers are priced in three different manners. The stone on top gets, as Mike said, the weathering from millions of years. The limestone has a little bit of iron oxide in it, so it will rust out. The stone that's on top or on the edges of the crevices and such is a nice soft brown color, and it is weathered because it has been moved around over those millions of years. That's the most expensive stone that they have. And then as you cut back, you will find the grayer stone underneath, which is the typical color of the stone in its prime sense. This is a lesser cost. And then, when they get to the middle of the shale ledge, they are breaking it off in chunks and it is a darker gray. So you end up with three price ranges of the stone, and the pieces on the edges are the most expensive. What I have been able to do over the years is learn a little about how to make it economical. The way to do it is to create a blend of the three types of stones and use as little as you can of the most expensive stone and as much as you can of the least expensive stone, but still get a coursing that helps lean it towards the softer beiger colors of the expensive stone. So in doing that, I think the mix looks better than buying all of the most expensive stone, and you can get a very nice randomness to it.

I think that if economics are important, you have to minimize the amount of labor shaping of the stone. We use the slate and other materials that cleft. You try to cleft it, cut it and put it on a wall.

Rollman:On Terrell Place, one way that we value-engineered was that we went to a thinner stone on the floor. We went from 3 cm to 1 cm, and used a crack isolation membrane to help reduce cracking. On the exterior of the building, we did stone on a pre-cast backing. We priced two different finishes of pre-cast versus stone, and it was only a little bit more money to use natural stone. It was very thin, and we casted it into the concrete.

CSTD:We talked about some practical lessons learned from using stone. Do you have anything else to share here - positive or negative?

Urbanek:We did a church [addition] a while ago using Fon du Lac ledgerock. We were trying to match the existing church, which was small. The new church was about five times the size as the existing, but they wanted to use the same material. So, that was my first time using Fon du Lac limestone in the ledgerock capacity. The existing church had everything running horizontal as the ledgerock, except these large panels of the same stone that were roughly 2 feet vertical by about 18 inches horizontal. We did our drawings and elevations, and our specifications said to put these large panels of stone in randomly. Well, 100 years ago, stonemasons knew what “random” was, but in this period of time, we are not random people. We are a very orderly people, and we try to take randomness out of things. So when you go look at this church today, you see that these random stones are very much in a pattern. It was just the way that they put them up. They didn't do it on purpose, but they just got into a system and this is how it happened. I talked to one of the stonemasons, and I said, “This doesn't look random at all.” And he said, “You know, the only way you can do that is to change your stone team every day, and it will be random.” I learned a lesson.

Rollman:I'd say for me the lesson usually comes from the fact that stone is a natural material. This Terrell Place project was a classic case of picking material from a 1-foot x 1-foot sample. We went over to Italy, and we saw something very different. I think there is a lesson in the risk that you take in selecting a stone that has a large range.

Dobbs:I learned a pretty good lesson: never ever use unsealed stone in a bathroom - ever.

Urbanek:The lesson that I have learned over time is that if someone tells you that you can't afford stone, I wouldn't just stop there. We have done a number of projects in stone where people thought at the most they would get brick. If you do it right, and it is part of the overall architectural concept, it can be made to work. You just have to understand what you are doing and work at it. You already know that per square foot, [stone] is a material that takes a lot of energy to get on the face of a building. So there is a cost associated with that. But once it's up there, it is absolutely beautiful.

Dobbs:Following what was said earlier about the older [stonemason] who knew just what to do with a problem, I've learned when to listen to the experts. Just because our specification or detail says a stone has to be 37 1/2 mm thick, it doesn't necessarily mean it is right. Also, it doesn't mean that it is cheaper than a 50-mm-thick stone. We have discovered that sometimes, if stone is fragile and there is a potential for breakage during shipping, a thicker material will cost you less than thinner material. Thicker stone also makes installation easier because slots can be cut more easily in a thicker material. And, we discovered that it is cheaper to do more rather than less. So, I've learned to listen.

Rollman:I also want to highlight some of the unique ways that we have used stone - one of which is the [National Academy of Sciences in Washington, DC], where we worked with Larry Kirkland, the artist. He conceived a story about science in research in the lobby. There was a method of applying rubber to the wall, and that was used as the template for sandblasting. He used an acid dye to fill in and create these dark patterns. This I think is a unique way of finishing stone - it's not just polished or honed. It actually becomes a piece of art.

CSTD:How much do you supervise the installation of a project? Do you have to go to a site often, or does it vary from project to project?

Urbanek:We try to do mock-ups all the time - especially when it comes to stone. That is one of the prime things that we are really adamant about. We want as large as a mock-up as we can, so we can avoid a lot of back and forth. Some projects require us to be out there more than others depending on the complexity, but I would say that one of the things that we try to do very much is get that mock-up.

Rollman:Even though my jobs tend to be local, I agree with that. Once a mock-up is done, and you see the way the project is going, we may go to the site for our own interest, but we don't feel it is our responsibility to manage or inspect. We are observing to make sure that it is being installed as approved.

Dobbs:It depends on the job. Some jobs will go the way Andy suggests, and others require much more intensity. It all depends on what you've asked them to do. If what you have asked them to do is complicated in an installation sense, then you have committed yourself now to go there to make sure that they are doing it right. The mock-up may not catch all conditions. On the American Indian Museum, we did a one-and-a-half-story-tall, 30-foot-long, full-scale mock-up, with every condition that we could think of in the building. It cost $500,000 to do the mock-up, and it stood there for months. We ripped it apart and put it back together again [repeatedly], and we got it just so, and I was on site every day for three years after that.

CSTD:What would you say is the most challenging aspect in working with the stone industry as opposed to other industries such as tile, carpet or wood?

Rollman:If you look at the manufacturers of tile and carpet, they tend to push us. They are constantly introducing us to new materials. They are constantly pushing the envelope - especially with sustainability. Also, [they need to be] coming up with a better way of introducing a product to us - especially in dimensional cut stone. Porcelain tile is really hot right now. There is a lot of condo work going on. So we have plenty of catalogs. We also use a lot of stone, but it is just much more difficult to find out about new products.

Dobbs:It has its positive side and negative side. The idea of the small craftsman going out [to a project] with the manual hand experience and the “love of the earth” aspect of it going away is sad. And yet, being able to say, “I want a Grade A, Number Two finish,” and knowing what you are supposed to get - as you do with stainless steel - would be helpful to a large extent.