Resiliency in Construction, Part 2: Ideal Resiliency for Your Building

by Andrew Dykeman, Project Executive

In the first installment of our resiliency series, we discussed the case for resiliency and its relationship to economic security and business continuity. Sounds great in theory, but what does it look like in practice?

Like most things in life, the answer can be complicated.

The right mix of systems and solutions for one building could be entirely different from what’s best for a building located directly next door. Ultimately, the prescription for your ideally resilient facility will depend on a balance of available budget, level of risk, and the operation your building needs to perform after a disruptive event has occurred. It will also depend on the bones of your existing structure, site and soil conditions, as well as the building’s height and mass.

While occupant safety is the most important factor in every situation, for building owners looking to make informed decisions about how to design or retrofit a building to ensure asset security and continuity of business, there’s a lot to think about. Let’s break things down one at a time.

The first and likely least surprising consideration is the budget, as it will be the driving factor for everything that follows. If you know what you have available to spend, you can start to prioritize what’s most important for your project.

Different building uses and business functions call for different priorities. If the building hosts emergency services, first responders and/or infrastructure service providers—including power and water, this is considered mission critical, and therefore is subject to a higher standard. The scope of reinforcement through design or retrofitting systems for a mission critical facility will need to support a building that can remain operational in the aftermath of a natural disaster.

In a new construction environment, the primary cost drivers for resiliency are the structural systems employed and the level of operational certainty and system redundancy required in the power, communication and mechanical systems.

Of these cost drivers, the structural system upgrades are usually the easiest to quantify. While every building is unique, and costs will vary depending on a multitude of contributing factors, these premiums are determined relative to the overall cost of the building.

A client recently asked us to analyze the cost difference of their new structural steel building in three different scenarios: one as if it were built to base code, another if the building were built to be more resistant to an earthquake using additional bracing, and finally if the building could survive an earthquake with little to no damage using base isolation. The cost premiums for scenarios two and three, relative to the base scenario for this particular structural system, were 5% and 11% respectively.

During a seismic event, a building with a fixed based can whip back and forth against the movement of the ground, which can cause severe damage. Introducing base isolators under the foundation, the building is decoupled from the ground, like putting your building on shock absorbers. The isolators limit the transfer of the ground movement to the building, limiting or even eliminating damage to the building structure.

The cost premiums to increase resiliency in the mechanical, electrical and other building systems is another story. The solutions for these systems are varied and numerous. On-site power generation, water storage, redundant mechanical systems are all various options available to employ. Generally speaking, we can see cost premiums for upgrading these systems in the 4% to 23% range of total project costs.

Many owners do not have buildings that serve a critical emergency response function but may have a desire for a building that can be occupied after an emergency. These include businesses that communities may depend on, community centers and other businesses that may serve as shelters post disaster.

Lewis recently analyzed the cost premium to upgrade a gymnasium. While the building is designed to current code and would be safe the for students to exit in a seismic event, it could be damaged to the point of not being useable post event. In that instance, the building would see a 4% increase in project cost in order to strengthen it. The building would then have a much higher likelihood of surviving the event and be able to be used as a disaster shelter post event. We expect these types of solutions will continue to be discussed and employed in our community as resiliency becomes a more significant part of the design and decision-making process.

All that said, business continuity doesn’t always require an operational building. If your business can maintain off-site servers and allow for remote work, then you might decide to retrofit to such a standard that the building will be safe to exit during a disruptive event. The tradeoff is that you’ll pay less up front but assume higher financial risk later depending on the extent of the damage.

In all scenarios, the safety of building occupants is the top priority. Understanding and incorporating resiliency takes effort from the whole project team to incorporate each client’s unique balance of budget and function.

This is the second installment of a six-part series about resiliency in construction. Here, we discussed the factors that determine the ideal resiliency of a building. Next, we’ll go deeper into the various systems that ensure a building’s ability to bounce back from a structural threat.

Project Executive Andrew Dykeman is an authority in sustainable construction and resilient systems. Andrew has managed some of Lewis’ most resilient and self-sustaining projects over the past two decades, including the Central Lincoln People’s Utility District, the Eugene Water and Electric Board Roosevelt campus, Elephant Lands and Polar Passage at the Oregon Zoo, and the Lane Community College Downtown Campus.