The Guggenheim Museum in Bilbao is perhaps the most celebrated cultural project that I have worked on with Mr. Gehry at the office. It is hard to believe that it has been 15 years since it opened back in 1997.

I still remember the first visit to Bilbao, we were very taken by the green hills that surround the city and the river that flows through the center of the city; but we were the most impressed by Bilbao's industrial character. This is what we tried to capture in our design.

From those impressions, we established five urban design principals for the museum: 1) To orient to the center of the city with an entry plaza 2) To relate to the river with a water garden 3) To create a high-reader visible from the old city on the other side of the river with a tower 4) To connect both sides below the Puente de la Salva bridge with a 90M-long gallery 5) To celebrate the industrial character of Bilbao with the sculptural expression and the materiality of the museum.

To translate these concepts into architecture, we worked with physical models as a way to sketched three-dimensionally. We began with very rational and rectilinear representations (model on left), and evolved the design sculpturally, with many studies and iterations (model in center and right).

During the design process, the walls of our studio were decorated by fragments of shapes, cutouts, and photos of various studies models that we have created.

To further refine the design, we constructed a 1:50M scale model (center) that can be taken apart to study the interior spaces. We worked closely with the curators from the Guggenheim to make sure that the galleries we designed would compliment their curatorial vision.

Since the museum opened, the galleries have hosted a variety of exhibitions, from large-scale contemporary sculptures such as Richard Serra, to abstract expressionists paintings, to traditional Chinese art, and the Art of the Motorcycles.

This series of models represent the design evolution, from the 1:500M competition model on upper left, to the 1:50M model to study the interiors on lower right. This process began in 1993 and the finished building was inaugurated in 1997.

As expected, when we first presented the design to the city, many politicians were shocked by the unconventional look of the design. But as the building slowly came into existence, the community began to embrace it. They began to understand that our design relates to the existing city like two generations having a conversation.

A common mis-perception is that a building that looks so sculptural must be very expansive. With the help of digital technology, we were able to make the exuberant design of Guggenheim Bilbao affordable for construction, with very few custom-fabricated pieces.

This process began by using the digitizer to record the surface geometry of our final design model into the computer. (Since this photo was taken over 15 years ago, the technology has evolved quite a bit now with new devices to scan the model, but the concept remains the same.)

From the digitized date base in the computer, we began to analyze the geometry with the aerospace software CATIA. For example, the colors in this computer model represent the range of curvature in the design surfaces; from green (surfaces that could be constructed with standard panels) to red (surfaces that require custom fabricated panels). Using CATIA, we were able to rationalize the complex geometries of the design model, to communicate in a simple and understandable manner with the contractors and fabricators.

Using the 3D computer model as a central database also allowed the design team to have direct, real time interaction and dialogues with the engineers and consultants. Working closely with the structural engineering team - Skidmore Owings & Merrill in Chicago, we developed a structural framing system of 3M x 3M grid. This grid is repetitive and can be made with straight, standardized steel members. The contractor was able to erect the grid just like any other building without incurring premium cost in labor.

From the 3D computer model, the team worked directly with the contractor and fabricator to streamline the Project Delivery process. By making more accurate calculations of construction materials, we were able to to eliminated change orders and reduce construction waste.

For the exterior finish of the museum, we looked for a material that would compliment the quality of light in Bilbao in a beautiful way. When we came across a sample of titanium in our studio; we initially thought that it would be too expansive. But during the tender process, the Russians released a large amount of titanium into the global market. As a result, titanium became affordable.

Titanium is a also much lighter in weight than stainless steel, so we were also able to make savings in the tonnage of structural steel.

Much has been said about the 'Bilbao Effect' from an economic perspective. It is a good example of why arts and culture may be the best investment, and that creativity and innovation are the ultimate renewable resource.

From my perspective, the real achievement of Bilbao is the way the museum has inspired a sense of pride for the community. Perhaps the real impact of Bilbao is that it has created a milestone for excellence, and it has established thinking outside of the box as the norm for the next generation.

Finally, I think that what made this project so special and enjoyable, is the experience of working with many extraordinary people. The Guggenheim Museum Bilbao would not be possible without the collaboration of the team.