In the late 1960s, Paul Rudolph, who was, at the time, one of the most respected American architects of his generation and who was dean of the School of Architecture at Yale University, wrote the following: “In architecture all problems can never be solved… Indeed it is a characteristic of the 20^th century that architects are highly selective in determining which problems they want to solve.” He posited that great architects make wonderful buildings only because they ignore many aspects of a building. He noted, “If we solved more problems, our buildings would be far less potent.”

Rudolph’s words epitomize one of the most powerful aspects and one of the most disturbing problems of 20^th -century thinking. Rudolph overtly favors narrowing the broad scope of an architectural problem in order to make it clearer and more manageable. He advocates concentration in order to obtain power and potency. He favors exclusion as a means to achieve intensity.

This attitude in architecture is consistent with 20^th -century notions in many disciplines where reductivism, oversimplification, and single-mindedness have led to negative consequences which we must now address in crisis proportions. In science, in politics, in education, even in art, we have sought clear, singular models, resisting complications as “static” in the system. In our frustration with the inability of those models to produce success, we have jumped from one model to another sequentially, searching for that one satisfying, clear, distilled direction.

In architecture, this reductivist attitude has produced a whole series of movements – Modernism, Post-Modernism, Late-Modernism, Neo-Modernism, Metabolism, Historicism, Brutalism, Deconstructivism, etc.-each concentrating on one or a few aspects of building, but none taking a really broad, synoptic view. The current interest in sustainability could be seen as just another one of those movements-something that will be “hot” for a while but will soon go out of fashion as some other set of interests supplants it.

But perhaps the destiny of this movement is different. Perhaps the 21^st century represents a more broad-minded kind of thinking, that is not content to ignore many aspects of a building in order to concentrate on a narrower band of interests. Perhaps sustainability is, in fact, precisely about seeing architecture as a broad, multifaceted endeavor which is greatly diminished when its scope is constricted.

I was very encouraged recently by reading an article written by two British researchers in an issue of the Journal of Architectural Education, edited by Kenneth Frampton and Steven Moore. Entitled “Reinterpreting Sustainability Architecture,” it does an impressive job of describing the full breadth of what sustainability currently means to various constituencies. Six different “logics” of sustainable architecture are described, covering issues as diverse as social equity, community participation, quality of life, health factors, expression of local cultures, regionalism, ecological consciousness, biodiversity, compact cities, and energy conservation, among others. The authors suggest abandoning “the search for a true or incontestable definition of sustainable buildings” in favor of just embracing its whole messy range of concerns under the broad umbrella of sustain ability. They suggest that the pursuit of “consensus that has hitherto characterized sustainable design and policy making should be translated into the search for an enlarged context in which a more heterogeneous coalition of practices can be developed.”

It is actually this inclusive attitude toward diverse design concerns that makes the notion of sustainability particularly appealing to me. Here is a way to look at architecture in the very largest frame of reference. How does it perform socially, functionally, aesthetically, and technically? How does it perform over a multigenerational time frame? How does it embody timeless human values like responsibility, intelligence, perceptiveness, creativity, and ingenuity?

For me, the beauty and the challenge of architecture is that, in the end, it is about life-all of life. Sustainability seems to accept that notion. Architects must be concerned with how many watts of electricity per square foot the building is consuming, but they must also be concerned about whether the lighting produced by that electricity is creating an atmosphere supportive of the functions that occur within the building. Designers must deal with conserving natural resources in the construction process, but they must also be sure they are producing a building which will have a long, productive functional life-which will not become obsolete and require premature replacement, negating the original efforts to conserve. Architects must avail themselves of opportunities to recycle and provide the option for future recycling in the choice of building materials, but they must also pay attention to whether the materials they select are contributing to promoting employment stability, developing craft and local culture, and engendering a sense of identity and community pride.

The broadest agenda of sustainability can never be fully satisfied or even fully optimized. Its range is so inclusive that some issues will inevitably even conflict with others. In the recent exhibition “Ten Shades of Green,” sponsored by the Architectural League of New York, ten exemplary buildings were chosen from around the world to represent the best of green architecture. Though each embodied great strengths in terms of sustainability, there was also room for criticism in every case. In sustainable design, perfection is not a realistic possibility. Balance, appropriateness, ingenuity, synergy, inventiveness, intelligence, and sensitivity are better criteria for evaluation.

In our own work over the last 20 years these have been our watchwords. We have always sought to make buildings which are appropriate to their place, their purpose, and to the people who use them. We try to make buildings that are poignantly expressive of the local values and culture of the populace they serve. To do this in a sophisticated way requires a strong degree of community involvement and community participation which we sincerely enjoy.

We pride ourselves on our ability to site buildings well so that they make a positive impact on the urban condition or on the landscape around them. We worry a lot about the building’s interaction with the sun, the wind, and the local ecology. We arc trying, in every project, to create a symbiotic relationship between indoors and outdoors – between man-made and natural.

We love building materials and we have always researched them thoroughly- where they come from, how they are made, how they might be used in a particularly evocative and sensible way. We have tried desperately, no matter what the budget, to build well – to make places that will last a long time and have real durability – technically, functionally, and aesthetically.

We did all of these things long before the term sustainability came into common usage. In the very first commission I ever did on my own – a tiny private library in West Lake Hills, Texas – issues now associated with sustainability were already of concern to us. The library was kept to a minimum footprint and was organized vertically in order to nestle within the canopy of a grove of large live oak trees. It tapered at the top so as to become the inverse of the tree’s boughs and avoid any substantial pruning. The natural environment was deemed primary and the little building a tenant that avoided intrusiveness.

Daylighting was important to us, though we did not call it that. We simply preferred natural light to artificial light as a resource for reading as well as other activities. We tried to make a relatively glare-free reading environment, learning explicitly from lessons of Alvar Aalto’s extraordinary Viipuri library of the late 1920s. We brought light from high in the room and from all sides evenly to minimize reflections and to allow a reader to shift positions in the room or chair without losing optimal light.

Minimizing resource consumption was also a high priority. Because the site was shady and located on a knoll that caught every available breeze, we tried to make a building without a mechanical cooling system. We placed well-shaded operable windows on all sides of the polygonal room to catch every wisp of wind. We also put operable windows high in the lantern so that as warm air would rise it could be exhausted, drawing in cooler air low from the shady understory of the grove. We even took the challenge of heating the building without a mechanical system, installing a recirculating fireplace with ducted distribution of warm air from a plenum around the firebox directed to other parts of the room through simple convection. In 1984 the little library won an energy conservation award where one was required to submit utility bills for heating and cooling. We had nothing to submit.

Materials were earth-friendly and very local. The wood for framing as well as even finish carpentry for bookshelves and balustrades was farmed East Texas Pine. Limestone for both interior and exterior walls was quarried about 20 miles from the site. Stone flooring was a refuse material from the quarry created when large rough-hewn blocks were first sawn to dimensional units. We turned the sawn sides of the refuse pieces up for the floor, placing the rough side down into the grout. Fieldstones for the fireplace were gathered from the site.

Neither we nor the client was trying to make any grand statement. We were just building in a way that seemed sensible, economical, and sincerely respectful of the land we were inhabiting. Twenty years later, the client is still enjoying the little library immensely. Though we did make provisos for the addition of mechanical systems, they have never in stalled them. They live with more temperature variation than most people in a coddled era would like, but it is impressively temperate in the space even on a hot summer day or during a rare cold winter spell when they are obliged to keep firewood picked up from the site and the fireplace stoked.

As this broad definition of sustainability has emerged over the last several years, we have embraced it and have benefited enormously from the dialogue it has provoked. As the two following projects demonstrate, the issues become far more complex and difficult at the scale of large buildings and when dealing with institutional clients than they were with the little library. But the passion for economy, simplicity, straightforwardness, and a genuine respect for nature and natural forces remains the same.

ROBERT E. JOHNSON STATE OFFICE BUILDING
Located on a very visible site a block away from Austin’s State Capitol Building, this prominent 320,000-square-foot civic structure was designed to be home for eight of Texas’ legislative service agencies. From the very beginning, it was sponsored by the Texas State Energy Conservation Office to become a model of sustainability for future state office buildings. A broad range of consultants, including the Center for Maximum Potential Building Systems of Austin and Berkebile Nelson Immerrschuh McRowell of Kansas City, were involved in research and systems development.

From the earliest site-planning stages, a commitment was made to filter every design decision through a sieve of sustain ability issues. Though an earlier master planning effort had suggested a squarish office building set in the midst of a ceremonial lawn like most of the other recent state buildings in the area, an immediate effort was undertaken to get permission to alter the master plan both to produce a thinner, more exterior-focused building, and to create better scaled, more usable outdoor spaces.

The approach we suggested was to break the building into two thin bars – one creating a strong, formal edge to Congress Avenue (the main spine of downtown Austin ) and the other defining a somewhat more informal boundary for Fifteenth Street (a major east/west arterial ). The two bars, along with an earlier-phase garage, would then define an intimate north-facing court which could form an internal green space for the complex. The conference center, a part of the original program meant to serve not only this building but adjacent ones as well, was pulled free of the two office blocks and allowed to occupy the cast edge of the court. This accomplished three goals. It shrouded the harsh edge of the parking garage; it provided a smaller-scaled element to create a more intimate feeling in the court; and it created constant activity in the court as people came and went to meetings and as they took breaks on the conference center porch which faced the court. The shapely conference center pavilion was angled slightly so as to link the new court with a pleasant green space dominated by two huge live oak trees across the street.

On the fifteenth Street side of the building there were several large oak and pecan trees that meandered onto the site from the street space. The office bar there was carved away to accommodate the canopy of the trees as well as to provide additional light wells intermittently for deeper daylight penetration in the long south façade. This also helped break down the scale of the massing on the less ceremonial Fifteenth Street frontage. At two of the light wells, the ground floor is hollowed out straight through the building for a breezeway focused on a particularly fine live oak in one in stance and for a sallyport in the other.

The result of all these site-planning moves that optimize usable outdoor space and create features out of existing vegetation is to make the whole environment feel softer, greener, and more natural than it would have otherwise. Occupants looking out on the court enjoy quiet natural vistas. Windows opening onto light wells filled with mature trees create an entirely different work experience than if they looked out on busy Fifteenth Street directly. One goal of sustainability is to keep human beings more connected to nature and natural forces. Even on this very urban site, small urban design moves went a long way toward accomplishing that goal.

Site-planning and ground level treatment also help promote amenable pedestrian movement in the district. The breezeway and courtyard serve as convenient and pleasant cut-throughs creating shady paths from the parking garage to the Capitol Building or from the conference center toward nearby office buildings. Covered arcades line two edges of the building where pedestrian movement is frequent, providing pleasant sheltered pathways for exterior circulation. Arcades, the breezeway, the court, and other terraces are all linked and carefully related to entry points, lobbies, and even staff lounges to invite easy everyday movement and interaction between indoors and outdoors.

The general massing of the buildings was also fundamental in helping to accomplish another important sustainability goal – natural daylighting of as many office spaces as possible. The thinner section of the building bars and the light wells on the south face made natural light much more available than the massing of the master plan scheme. Large apertures on this expanded building face were carefully articulated in response both to exterior orientation and to their role in lighting rooms within. Windows rise from desk height to 12 feet above the floor. There is a thick horizontal mullion at the eight-foot six-inch level which contains perforated blinds controlled by the users. Below the eight-foot six-inch line the material is heavily treated low-emissivity and ultraviolet protective glass on the south and west faces to maximize day lighting with out getting excessive heat gain. On the long south face there is also a light shelf at the eight-foot six-inch bar with a specular metal surface on its reflector side which catches light from the upper glass pane and bounces it deep into the building. Though still a low-emissivity glass, this upper pane is rated for a bit higher light penetration than the lower pane. The flow of natural light through the building is enhanced by clerestory windows above seven feet on interior partitions parallel to outside walls. These allow for privacy at eye level, but provide deep light penetration through the building above.

Fundamental to the success of the daylighting strategy in the building were the tall ceiling heights at the building’s perimeter, essential for bringing light in high at the edge and distributing it deep into the building’s center. The height is accomplished, in part, by close coordination of mechanical systems to virtually eliminate continuous plenums or hung ceilings at the edges of the building, and, in part, by utilizing a thickened flat slab structural system which eliminated the need for deep perimeter beams. It is in this coordination between structural, mechanical, electrical, and environmental characteristics of a building that fundamental sustainability advances are made.

At every step, technical systems of the building were pressed for greater efficiency and reduced resource consumption. Electrical loads, especially for lighting, were cut wherever possible. Coupled with the daylighting, dimmable ballast fixtures and automatic sensor switching devices drastically reduced electrical requirements. Lessening heat generated by artificial lighting along with careful fixture and equipment selections allowed reduction in required cooling tonnage. Performance monitoring systems and a thorough commissioning process further ensured efficiency of operation.

Careful and deliberate use of building materials was also an overriding theme used to produce both high standards of building performance as well as strong architectural character. Inspired by the powerful materiality of the 1888 granite State Capitol Building down the street, the Robert E. Johnston (REJ) building was conceived as an architecture based equally in material technology and appropriate expression of purpose and place. The building’s materials became the essential common denominator addressing a broad range of issues from contextuality to sustainability.

Design decisions at every level – from the frame, to the skin, to interior finishes, to furnishings – were shaped by a constant consciousness of how appropriate materials usage could guide and inspire the design process. A robust concrete structural system composed of rectangular columns and flat slabs thickened at concentrations of structural loads was conceived, not only to be economical and long-lived, but also to give the building a feeling of heft and permanence for its public purpose. Concrete, as opposed to steel, offered the opportunity to expose the structural system inside and reveal the strong, durable nature of the building even in office environments which are so often dominated by a feeling of transience and impermanence. Exposing the concrete frame also accomplished the sustainability goal of reducing redundant systems with their wasteful duplication of materials. Avoiding hung ceilings wherever possible resulted in a reduction of initial resource consumption as well as elimination of one of the elements of building assembly which deteriorates most rapidly. The concrete flat slabs also facilitated the accomplishment of other sustainability goals, as mentioned earlier, by reducing structural depths at the building edges allowing greater daylighting opportunities.

The concrete itself was made more “earth-friendly” by replacing part of the cement (35 percent in some portions of the building, 28 percent in others ) with fly ash. A finely divided inorganic residue which is a waste byproduct of coal combustion, fly ash offers the opportunity to find a very useful and economical purpose for a material which otherwise ends up in unsightly ash dams dominating the industrial landscape. (In 1998 the U.S. produced 44.9 million tons of fly ash.) Replacing cement with fly ash not only helps alleviate a serious waste disposal problem, but also reduces consumption of cement and all the energy resources and toxicity required to extract and process it.

The building’s skin, like its frame, grows out of a careful investigation of the rich potential contribution of materials to both building character and performance. Granite was selected as the predominant exterior material for both its toughness and its visual qualities. The pink native Texas stone ties the REJ building closely to the adjacent State Capitol complex and also appropriately bestows the attributes of dignity and durability on a structure housing government agencies.

The granite was quarried about 50 miles from the site, in Granite Shoals, Texas. The actual configuration of the stone is very unusual for a contemporary building. The granite is load-bearing, carrying its own weight rather than being hung from the concrete frame. Stone thickness tapers from 14 inches on the ground floor to eight inches at its highest point. This reinvigoration of a time-tested construction method was employed both to exploit the inherent strength, mass, and weight of the granite and to reduce dependency on vulnerable metal hangers concealed in moisture-laden cavity spaces. Stone finishes are either cleft or sawn, techniques chosen over more energy-consuming processes like polishing or flame-finishing.

The granite is stacked in vertical piers with spanning elements made of precast concrete- a more contemporary local material reliant on abundant Central Texas aggregate supplies. An aluminum curtainwall system was selected after careful analysis of energy performance, location of source materials, durability, and available finish properties. Spandrels in the curtainwall are zinc, chosen for its longevity and nontoxicity as well as for its color and texture, which complements the gray-flecked granite.

Inside the REJ building, a similar set of concerns prevailed for the generative role of materials in creating a healthy, supportive, and responsible environment. Wood, which is employed in both the ceilings and walls of public spaces for its richness and warmth, was specified to be from sustainably managed sources that are “smart wood certified.” Wood products throughout the building, including medium density fiberboard (MDF) employed in extensive cabinet work, use no urea-formaldehyde. Metal studs in partitions have 65 percent recycled content. Gypsum drywall has 100 percent recycled paper on face, sides, and back, and partial recycled gypsum in the core. All paints and other finish coatings are water-based with low- or no-volatile organic compounds.

Colored cementitious toppings are used for hard surface flooring. The choice of carpet stemmed from the manufacturers ‘ commitment to sustainable manufacturing processes. Specific product selection was based on high-wear performance, recycled material content, and ability to minimize use of adhesives in installation.

The design team devised a matrix to evaluate the appropriateness of various materials under consideration. Factors rated included where the material was extracted and how it would be transported to the site, toxicity of the material both during manufacture and after installation, recycled content as well as recyclability, and life-cycle costs. The same matrix was used by the team who selected furnishings, resulting in the use of almost 13,000 yards of fabric made from recycled polyester and plastic bottles for work stations as well as a wide range of other new products drawn from manufacturers employing manufacturing protocols that drastically reduce pollutants.

This kind of thorough, “all-issues” approach to sustainability requires a strong team effort including the client, architects, engineers, and consultants. It requires injecting sustainability considerations into virtually every design decision as well as into technical considerations. It necessitates a great deal more communication and coordination among team members than in a more normal design process.

AUSTIN BERGSTROM INTERNATIONAL AIRPORT
This new passenger terminal for Austin is a 25-gate “start from scratch” facility which has 680,000 square feet of space on three levels and cost $140 million. It was the first major passenger facility to be constructed in the U.S. after Denver International Airport opened in 1994. It took two and a half years to design the project and three years to build, and was completed in July 1998.

The following are seven sets of sustain ability issues that we explicitly addressed. These are not comprehensive by any means, but they will give a flavor of the way in which this broad, inclusive notion of sustainability might impact design. The first set of issues had to do with treatment of the site.

The site is a former U.S. Air Force base. The new airport was located here in order to reuse a very high quality 12,250-foot existing runway, so that even the decision about locating the airport was an act of recycling. Every effort was made to reuse as many buildings on the Air Force base as possible. The main administrative building was converted to a hotel and other ancillary buildings were used for Aviation Department offices. Homes for military personnel on the base were moved to become city-owned low-income housing. Mature trees were carefully surveyed and retained where possible, but over 30 large live oak trees which could not be kept were success fully moved and replanted on-site.

All demolished concrete on the site was recycled as sub-base material on other airport paving projects. All demolished asphalt was recycled as fill. All excavation materials were reused for other projects on the site. Insofar as possible, the invested resources on the site were respected and utilized to the fullest extent. Two basic tenets of sustainability – reuse and recycle – led decisions about the site throughout the project.

A second set of sustainability issues dealt with shaping the footprint and massing of the building on the site. Initial studies for the location and shape of the building were dominated by a pair of important environmental concerns. First, we were intent on keeping the amount of site regrading to an absolute minimum. We also wanted to avoid dramatic changes in patterns of site runoff and rainwater evacuation. Though this was a relatively flat site, there was still a significant fall across the enormous footprint necessary for the terminal apron and runways. The long, thin shape of the terminal and its orientation were conceived to cut across as few contours as possible requiring dramatically less cut and fill than the initial master plan had called for.

The natural fall of the site was used to our advantage by making the long, thin terminal building a retaining wall and creating a section which nestled into the slope. The airplane apron could then be higher than the baggage claim area, providing a very efficient path for baggage conveyor belts.

Another significant environmental factor shaping the footprint of the building was sun orientation. We knew from the beginning that daylighting would be a very important factor for us in achieving both energy efficiency and the appropriate “feeling” and “spirit” for the terminal. The building was, therefore, stretched very long on the north/south faces and very short on the east/west faces. In our climate, north light is gentle, relatively benign and very useful. South light, if properly shaded, can be beneficial for maximizing light in the winter and keeping out direct sun in the summer. East and west sun are more difficult to control, and west sun especially contributes problematic heat gain in late afternoon in the summer when it is most harmful. So, in the end, the building is almost ten times as long as it is wide in its thickest part. It is an almost perfect sun and light catcher for our climate.

A third critical set of sustainability issues had to do specifically with heating, cooling, and otherwise providing technical systems for the terminal. Natural light is a very important theme for the building and an essential clement in conserving energy. In this internally loaded building type, where heat is normally generated primarily by artificial lighting, machines, and people rather than heat gain from the exterior skin, we sought to minimize heat produced by light fixtures. By maximizing the benefit from cooler natural light, we were able to significantly reduce reliance on artificial light.

Utilizing readily available insulated glass technology we could employ the natural light without excessive heat gain. We have over 102,000 square feet of glass of three different types. One has a ceramic frit. The others are varieties of low-emissivity glass. Windows on the south have six-foot-deep horizontal sun shades as well as a concentration of the higher-performance low-emissivity glass. Windows on the north side need no sun shades and can even have a somewhat less protective glass. The various glass types and sun shades make a subtle, but complex pattern on the south building façade facing the airfield, which contributes visual interest as well as energy performance.

Many other energy-saving strategies are employed in the building: a reduction of evening ambient light levels with concentration on task lighting in hold rooms and eating areas; sophisticated automated controls including occupancy sensors, photocells, and timers on both lighting and heating/cooling systems; a large ice-storage capability which allows off-peak energy usage; and high-efficiency motors with variable frequency drives in mechanical systems, to name a few. The building was conceived-from its siting to its massing to its skin to its technological systems – as a great efficient machine which first relies on full utilization of natural forces and then supplements these with the most resource-conscious mechanical means possible.

But it was certainly not the case that the airport building was viewed simply, or even largely, as a technological machine. Our primary goal was to make it a very personal, user-friendly place which would be embraced by the citizens of Austin as an important public place and a powerful symbol of the city.

In this regard, a fourth set of sustainability issues in the project had to do with design process and incorporating a broad range of input and involvement. Our client was, in fact, the citizens of Austin who voted the bond money for construction. We worked very closely, of course, with the mayor and City Council, who, as elected officials, represented the citizenry. In addition, a committee of 22 people was appointed to work with us in a much more detailed way. This committee worked very hard over a period of almost two years. As representatives of many diverse constituencies in the city, they helped us understand various points of view. In addition to working with this special committee, we also made dozens of presentations to a range of other groups and committees in the city, broadening community participation even further.

But the client for the airport was not just the public and their representatives. The building had to respond to very specific needs of the airlines, the rental car companies, concessionaires, and various other contractors and vendors who operate out of the terminal. Literally hundreds of hours were spent in meetings with the airlines and other private business ventures trying to understand their specific needs in this building. Going through such an elaborate and complicated input process is essential in order to fully embrace a fifth set of sustainability issues that have to do with building function.

Virtually everyone we spoke with was unhappy with most other airports they had visited or worked in. They strongly emphasized the importance of convenience for passengers. Austin is an origin and destination airport – not one where people are changing planes, but a place where more than 95 percent of passengers are going from ground transportation to the gate or vice-versa. This means the challenge was to create the very shortest and most direct path possible between the curb and the gate. The basic diagram of the building optimizes that path.

Two entrances at the curb place passengers at the most central access point for all the gates. The building is divided into two distinct parts – landside and airside. As one enters the landside, ticket counters are immediately visible on either end. Baggage claim is in the center in an open well. Straight ahead are security checkpoints, and just beyond that, concessions and the gates.

The nine gates in the crescent-shaped portion of the terminal are used for commuter flights – short hops, often to nearby Houston or Dallas, which depart every hour. The distance from the curb to these gates is as efficient as possible. Many business people in Austin take these flights two or three times a week for day trips and such ease and efficiency is greatly appreciated. Concessions are located immediately adjacent to the hold rooms in the great central space we call the “Marketplace.” The process of going through security, checking in at the gate, grabbing a bite to eat or a magazine while waiting to board, and then loading the plane is greatly facilitated by this easy, convenient orientation of parts. The atmosphere in the Marketplace is lively and urbane. There is cafe seating dispersed casually throughout the space. A live music stage is in the center of the crescent where Austin ‘s famous music scene is on display in an easy, unpretentious way. There is a good feeling here-friendly, warm, open, and inviting.

Another prominent functional concern in the design of the airport was wayfinding. We tried hard to make the building very transparent and legible to users. We wanted to create a place where people could see or intuitively sense where they needed to go via cues given by the building. From the entry points we tried to make as many airport functions as possible visible immediately so as to aid in orientation.

Ticketing lobbies are clearly available to one side. Security checkpoints are straight ahead. Concessions and gates are visible just beyond that. Even baggage claim can be easily located down below-not in the kind of low-ceilinged basement common in many terminals, but in a bright, open room which contributes to the liveliness and “action” of the larger building.

As passengers move through the terminal, the notion of easy wayfinding continues. The crescent shape helps to locate them in the large central room. Even as passengers first exit the airplanes, they know where they are in relation to the center and the entry/exit points, just by the shape of the space. Wayfinding is, of course, additionally supplemented by clear, well-located signage.

A sixth set of sustainability issues which helped formulate the airport’s design had to do with materials selection. At every stage an effort was made to employ materials which had low levels of embodied energy, came from renewable sources, minimized negative impact on air quality both in the manufacturing process and as installed, and would last a long time with minimum reinvestment in maintenance and replacement. These were tough issues to deal with in an airport where use is both demanding and constant.

Steel for the project, which is the predominant structural material, is 95 percent recycled. Concrete, which is used primarily for piers providing lateral bracing, employs fly ash to replace part of the cement. The primary finish material both inside and out on the landside portion of the building is a local Texas granite quarried about 50 miles from the site (similar to that used at the REJ Building, but a cooler, grayer color). Its toughness in an environment of carts, baggage, and jet fuel exhaust is crucial. It is used in thick slabs to increase durability and longevity. Corners are made of solid L-shaped pieces for protection from impact. Because the granite is local, embodied energy from transportation is minimal. We were able to work very closely with the quarry to employ the material in a way that minimized waste in the production process and gave us excellent color and texture consistency.

Inside the terminal, every effort was made to minimize redundant systems with their wasteful duplication of materials. Avoiding hung ceilings wherever possible resulted in a reduction of initial resource consumption as well as elimination of one of the elements of building assembly which deteriorates most rapidly. Steel decking and framing becomes the finish material throughout much of the public space of the building.

Where interior finish materials are required, they are chosen to complement the steel frame and granite piers and walls. Wood is used extensively, but always high on walls or ceilings so as not to be vulnerable to impact damage. All wood products were supplied from controlled growth forests. Much of the warm, wood-feel of the building actually comes from MDF (medium density fiberboard) which is made of waste material from wood processing. It is used frankly with a clear finish which exposes its character as a wood material, but also a modern industrial product. Another common wall material in public spaces is sisal – a natural fiber which is tough like rope. It can easily take the abuse required, but is also warm and rich in its color and texture. Seams, which are the least durable part of a sisal assembly, are avoided by placing sisal panels in an aluminum framework. The metal angles serve to keep carts and bags from banging against the wall as well as to protect vulnerable joints. The idea, well – illustrated in this assembly, is to use natural materials with low embodied energy, detailed in such a way as to last for many years and not require wasteful replacement.

For areas where eventual replacement is almost inevitable, our emphasis was on recycling. Toilet partitions and benches, for example, are made of recycled materials. Carpet, which is only used in low-traffic areas, is all recyclable. In these and other manufactured products there was great concern with chemical content. We as architects avoided urea formaldehyde, for example, in the MDF. We used paints and other coatings which were water based and have low or no volatile organic compounds. Throughout material selection we kept a keen eye on where materials came from, how they were manufactured, how long their life expectancy might be, and where they might be reincarnated into future useful products.

The seventh and last set of sustainability issues we addressed had to do with the building embodying a sense of place. I was delighted that one of the six “Competing Logics” of Sustainable Architecture described in the Journal of Architectural Education article mentioned earlier focused on buildings responding to “regional context” and adapting themselves to “local physical and cultural characteristics.” In order for a building to be truly sustainable, it must become an integral part of its physical and cultural context. It must embody a tangible sense of locality and place.

If we believe in the conservation of the richness and diversity of life on this planet, that belief should include protecting human cultural diversity. Any model of ecological sustainability must incorporate a retention of meaningful local cultures which enrich and sustain the long-term health and breadth of perspective on the planet. We are, in fact, very fond of the local physical and cultural context in Austin and enjoy very much the opportunity to try to infuse some of its vitality into architecture. The airport was an extraordinary opportunity in this regard. This is the gateway to our city and the one single place where more citizens come and go every day than any other. If any building should embody the culture of Austin, this one should.

We as a design team explicitly tried to incorporate several cogent characteristics of the region in the design of the airport. The natural landscape in the central Texas Hill Country is very rich and particular. It is an unusual amalgam of toughness, ruggedness, and strength alongside beauty, frailty, and vulnerability. We Austinites dearly love our landscape in Central Texas, and we like to spend a lot of time outdoors inhabiting it. Our creeks, rivers, and streams especially often take on mythic proportions becoming resources for recreation and social life. We have focused much of our identity as a city on outdoor places like Barton Springs Pool and Town Lake Park where the natural environment has spawned an open, friendly, congenial way of life. We are a real outdoor sports and recreation city, but with an emphasis on participating sports rather than spectator sports. We are one of the few cities our size in the U.S. with no big-time professional sports teams, and our big local athletic hero is bicyclist Lance Armstrong.

We have a very diverse population ethnically and, mostly, we thrive on the differences in our backgrounds. We’re a pretty tolerant city with a great appreciation for our various heritages and traditions. I think it is partly that same tolerance and appreciation that has generated a very lively and eclectic music and entertainment scene in Austin that ranges from country and western to blues and jazz to pop and rock. The Sixth Street Historic District downtown is our party room and the focus for a very vital and vibrant public life.

We are also the state capital, home to the state’s flagship university and a long-time center for history and government as well as for research and education. In the last few decades we have extended those longstanding roles to become a center for high tech industry. Dell Computers began and is currently headquartered in Austin, along with hundreds of other software and hardware firms. But technology in Austin extends well beyond digital and electronic technology. As a city we depend on intellectual capital. We have a highly educated populace with a real bent toward logic, analysis, and creativity. These are all very challenging cultural characteristics to try to incorporate into an airport.

As architects we addressed Austin’s love of nature mostly by creating a building that opens generously out to nature and the outdoors. As one observer was quoted when the building opened, “It feels like you are outdoors even when you are indoors.” This is in stark contrast to many airports which seem to be an interminable maze of corridors and internal rooms. We even thought of the big trusses in the central space as tree-like with lots of complex pieces growing out of a central trunk and providing a canopy for the well-lit space below. We planned that big, almost outdoors space to house the kind of informal social scene we so appreciate in Austin, and that has really happened. There is a very “Austin” kind of atmosphere – great food provided by local eateries like Salt Lick Bar-B-Que, Matt’s EI Rancho Mexican rood, and Amy’s Ice Cream in a comfortable cafe kind of setting. It is an unusually relaxing and stress-free airport environment which seems right for a city which prides itself in being “laid -back.” This is emphasized again by the live-music stage at the center of the Marketplace.

Another tie to nature comes, of course, in the extensive use of the local granite. It delivers the sense of toughness and ruggedness in our landscape, especially when placed in contrast with sleeker, more refined materials. We commissioned a series of carved glyphs in the granite executed by local artisan Phillipe Kleinfelter who is a real expert in the carving traditions that are a part of our local Mexican heritage. The glyphs depict leaves and seed pods of local trees – the same series of local trees like live oak, pecan, and mesquite that were used to name the original east/west streets in the 1839 plan of Austin. The story of that original plan and its references to nature – not only in naming east/west streets for trees but also in naming north/south streets for the rivers of Texas – is told in a series of terrazzo murals on the floor in the baggage claim area.

Throughout the airport, artwork and craftsmanship are used to embody cultural values. Murals depict Enchanted Rock, a landmark granite formation made of the same stone as the building, or a lyrical, series of scenes of a Hispanic family having a backyard picnic. An outdoor sculpture is based on seed pods of local flora. The grab-bar on stair rails is made of a hand-forged piece of steel made by local artisan Lars Stanley. It gives a softer, more humane touch where the body comes in contact with the building. The handrail in general provides just the kind of high-tech/high-touch combination Austin is known for.

The intellectual /analytical / high-tech ethos of Austin is present everywhere in the building. There is a clear tectonic nature of the structure which expresses logically how it is put together and how it works in a technical sense. It is also a precise structure, clean and exact. One observer described it to me as “mind candy” with lots of interesting pieces and details to be intrigued by.

In all of our work we are trying to approach architecture as a pluralistic discipline. We refuse to ignore many aspects of a building in order to make our buildings more potent as Paul Rudolf advocated. We revel in the various competing logics of design and enjoy very much grappling with the messy conflicts inherent in any full -bodied design process. We pride ourselves in making buildings that are responsive and particular to their circumstances and are not just signature pieces of their designers.