The $8.5B City Center project by MGM Resorts in Las Vegas continues to make the ENR news. The latest installment has some hired gun engineers claiming the Harmon Hotel tower will collapse in an earthquake. Their report states that the 28-story tower’s construction defects are “so pervasive and varied in character that it is not possible to quickly implement a temporary or permanent repair,” and questions “whether repairs are possible.”

Harmon Hotel on left

Local code officials had previously hired a structural expert who stated that the building is “structurally stable under design loads from a maximum-considered earthquake event.” So how can two professional engineers find such widely different conclusions?

It happens all the time. Even in what would seem a straight forward code evaluation, many assumptions allow design interpretations that tilt the answer in one direction or the other. I’m not opining bias by the engineers (though knowing your client prefers a certain outcome tends to color assumptions), I’m stating what I’ve seen many times.  Two structural engineers often aren’t going to come to the same conclusions. Sometimes they come to what appear to be opposite conclusions.

So how do you determine who’s right? The American West solution of a gunfight (ala OK Corral) provides a clear winner but may not get you closer to the truth. Here are some things to consider when facing conflicting structural evaluations:

1. Ask each engineer to clearly and simply write how his/her analysis varies from the other engineer.
2. Then ask each engineer to evaluate the differences.
3. Consider the motivations facing each of the engineers and make a simple list.
4. Submit this info to a third party engineer, not involved in the dispute, and get an unbiased opinion.
5. Weigh all the above and make your determination.