Innovation 2010: Burj Khalifa Engineer Shares His Secrets

William Baker, P.E., the structural engineering partner at Skidmore, Owings & Merrill, worked on three of the five tallest buildings that topped out in 2009.


Bill Baker, P.E.

But his (to-date) career-defining accomplishment is his contribution of the “buttressed core” structural system used at what is now—and for the foreseeable future will remain—the tallest structure ever built by man, the 828-meter Burj Khalifa.


The Burj Khalifa, photo by Iwan Baan

As if his engineering achievements weren’t impressive enough, Baker also proved to be a funny, eloquent raconteur in his presentation on Oct. 6 at Architectural Record’s Innovation Conference, a talk that focused on the “New Paradigm” in tall-building design represented by the Burj.

Here are some bullet-pointed highlights:

* Baker doesn’t want to hold the world’s-tallest record for long: “It would be a shame if we stopped here.”

* He revealed that a 950-meter-tall version was tested in the studio—and actually performed even better in wind tests than the finished building.

* What made the Burj Dubai possible? A “magical, new” material: concrete (OK, very, very high-performance concrete, with almost no water).

* The “Steel Age” of skyscrapers—the World Trade Center, the Sears (Willis) Tower, John Hancock center—is probably over. Much-cheaper (1/5 to 1/8 as much) concrete is the future.

* Former shared characteristics of skyscrapers: North America, steel, office buildings. Future shared characteristics: Asia/Middle East, concrete, residential (developers can get their money out faster).

* Baker walked down the entire height of the building looking for cracked link beams. The trip took about 45 minutes. No, he has never walked up.

* Surface roughness was intentionally engineered into the façade to “lubricate” the wind/reduce drag. This reduction in drag is the same reason why sharks have rough skin.

* Which is a greater engineering challenge: wind or gravity? It’s no contest. Wind, and all its instability and variables, is the real problem. “It’s much easier to manage gravity—it’s amazingly reliable,” Baker said to laughs. (Super-tall building engineers probably need to spend as much time in wind tunnels as their aerospace colleagues, he pointed out.) 

* He views the Burj as one giant beam coming out of the ground, which was trimmed back to get its final shape.

* The original cladding contractor going out of business had an upside to it, Baker joked: You got to see a lot of great structure as the building continued to rise without a skin blocking the view.

* To illustrate his “buttressed core” concept, Baker uses an image of a man holding an umbrella and leaning into the wind: the front leg is the core; the back leg, the buttress.

* In an image he showed of the building’s foundation, it was clear that the supporting columns were clustered/concentrated at the periphery, with relatively few in the middle. Baker said he wanted even less columns in the center, but placed the ones he did to satisfy colleagues.

* Among its many benefits, including resisting twists, the Y-shape of the building was crucial for a successful residential building, where views are so important. Residents are never far from a window—as opposed to Sears (Willis) Tower, where an office worker could be as far as 75-feet away. (The form also helps make sure those views are not into other apartments.)

* In a 50-year storm, the building will have 1 meter of sway. “It’s a very still building.”

* The Burj is essentially “the lightning rod” for Dubai—and as the building rose into the clouds, his email box would fill up with dramatic storm shots from colleagues.

* The luxury residential units sold out in two nights at an invite-only auction—now, there’s even a brisk black market for the invitations to the auction.

* At the opening ceremony for the building, Baker said he felt a little smug that he knew one of the big secrets--the building's exact height. But what even he didn't know was that the building was being renamed from Burj Dubai to Burj Khalifa.

* Inside Humor: Apparently at the firm itself, SOM stands for "Stay on Module".

(For an excellent, in-depth examination of how the Burj was built, and how its architects and engineers conquered the extreme height and climate obstacles posed by the project, I strongly recommend an article by my colleague, Josephine Minutillo: “Beyond Limits”. You can even earn CEU credits with the article.)