Archive for the 'young engineers' Category

Structural Engineering Childrens’ Book

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No, this isn’t one of my strange ideas, it actually exists. R. Buckminster Fuller and a photographer collaborated on a book that, to my knowledge, is the only extant children’s book (amazon) written from a structural engineer’s point of view.

It is an interesting book, if not short and unfocused in its selection of quotes. I selected my favorite for the scan above “If you want to do something good for a child… give him an environment where he can touch things as much as he wants.” I am not quite sure if this is something I will actually read to children or if it is something I read to remind myself that I was once a child.

R. Buckminster Fuller left a deep legacy, and definitely opened options for architects and structural engineers. The USPS issued a stamp for him in 2004 commemorating his contributions to society.

Recipe for Tall Buildings in Your City

The skyline of downtown Indianapolis

Tall buildings are a source of civic pride. They represent technical ability and economic power. Modern cities are defined by their skyline. Young engineers dream of adding their own touch to the cityscape. Tall building construction occurs in phases, and the most recent phase has probably died with the deepening recession. It may be 5 years or 5 decades before the next tall building trend. Tall building designers are a specialized group and are typically well positioned ahead of the start of the next trend. Unfortunately, this means that most engineers will have more experience with a skyline matrix than any actual famous tall buildings.

Construction of the newest Indianapolis hotel tower

For some reason people blame architects and engineers for the lack of tall buildings in their city. Certainly, architects and engineers have become more comfortable with taller buildings as time has passed, and taller heights are easier to achieve. New structural systems, new materials, and new ways to prevent swaying action has led to consistently taller buildings over time.

Throughout the twentieth century US engineers and architects led the way, but now the world is outperforming the US in terms of tall building construction. In fact, the number of foreign tall buildings built in the past decade is staggering. US construction continues along a slow trend but the rest of the world significantly outpaced the US in speed and total numbers of skyscrapers.

I can honestly say it is not our fault that the US is not building skyscrapers as fast. The design expertise for most of these tall buildings has come from US designers, so there is no doubt that the US is still leading the way in technical design. But there is still a feeling that the US is losing some sort of race to assert itself in the international economy.

In reality architects and engineers in the US have no influence over developers and their decisions to build new skyscrapers. No, the demise of US domination over tall buildings has been due to continued suburbanization. The American Dream has killed our cities.

Local market forces determine the height and size of buildings much more than any conscious design decisions. Iconic towers are even more rare than simple tall buildings, because there is a premium on design and construction for a truly unique building no matter what size it is. Developers are not willing to risk such a huge investment unless there is a clear chance for profit. For an in-depth study on this issue, consult The Economics of Super-Tall Towers (full text PDF available) published by CTBUH.

The Economics of Super-Tall BuildingsBasically, there are two considerations for developers:

  • How much additional square footage is profitable in the current market?
  • How big is my plot of land?

To get the height of their new building, they take the total square footage they want to end up with and divide it by the size of their plot.

Smaller plots are difficult for two reasons. The building must be taller for the same square footage, and the slenderness ratio makes the structural system more expensive. Developers are very happy with smaller buildings. They are less expensive, the elevators take up a much smaller percentage of the floor plate area, and they are not terrorist targets (easy to insure).

Companies are reluctant to sponsor construction of a new building these days. Especially with an on-going recession and plenty of leasable space available at inexpensive rates, very few are willing to risk the wrath of shareholders for the headaches of owning an iconic building.

All of this means that there must be a great, compelling reason to build tall. Here in Indianapolis, people desperately want the skyline to fill out. However, there are so many empty parking lots that developers will require a lot more demand before they are willing to take a risk on the premium costs of tall buildings.

Taking Indianapolis as an example, building more tall buildings may not be in our best interest. First, let us assume there is sufficient demand for more leasable floor space. For a tall building in a downtown so centered around car commuting, each tower must have a large parking garage next to it (or under it). In addition to the space lost to the garage (and any existing buildings that are cleared to build it), the road system must be expanded to accommodate the new commuters. Instead of densifying the downtown area it is now spreading out, losing nearby businesses in order to accommodate transportation of workers.

Basically, tall buildings are most appropriate in a dense, urban environment. If the downtown relies on car commuters, it cannot achieve the density necessary for successful tall buildings. Ignoring this caveat, certain communities have achieved tall building construction in a suburban area, but the buildings are out of context and at their base are nothing more than an attempt to draw attention and proclaim relevance as something they are not.

Anadarko Tower in The Woodlands, Texas

This type of environment is an entirely new invention. Drivers leave from their garage at home and drive directly to their garage at work. The need for roads and garages spaces the buildings apart so far that no infill development occurs. It is not an urban environment, it is a suburban environment with a sense of inadequacy. And I suppose if that is what people want, they can have it. But it is just as authentic as the EIFS clad southwest style grocery store sitting behind the hundred acre parking lot.

In order for a skyscraper to contribute to a dense urban environment and really make a difference in the local economy, a few items have to happen:

  1. all existing buildings must be leased at profitable rates (Indianapolis is not there yet)
  2. all existing surface lots must be converted to income producing leasable spaces, typically of a low rise density (Indy is at least one decade from this step)
  3. a public transportation system must be in place that can collect and distribute people from around the city to a single point (Indy is probably three decades from this)

If these requirements are not met, then asking for more tall buildings is just asking for a failed development. You can’t even give away a tall building downtown right now. There is just no demand to fill it.

So, if you are a fan of urban spaces and want to see more investment in your skyline, here is a simple recipe:

Live downtown
Don’t just take up space, take up space in the central core. Without a strong demand for leasable space, no additional supply will be built.

Work downtown
Look for work options downtown. Petition your office decision makers to locate in the central core. Once again, this increases demand and makes it an easy decision for the city and developers to move forward on their plans.

Use public transit options
Without public transit, cars will need to be parked and moved around. This dramatically reduces density, and makes tall buildings less viable. Pedestrian options are reduced as well.

Support local business
The businesses most likely to lease space in that shiny new building are local ones.

Support infrastructure initiatives
Expect to pay higher taxes. The extra costs associated with the urban core are manifold, including security for tourists and commuters, reconfiguring water & electric services, and caring for indigents. Don’t be upset about it, because this is the cost of society. For when someone isn’t paying their share, the rest of us must pay it for them.