Design for Resilience
Resilience is the capacity of an entity to recover
quickly after a strain. It is a term now heard frequently in
reference to the built environment, cities, neighborhoods and
buildings, but often narrowly focused on disaster preparedness or
structural design. However, an expanded view of resilience is
taking hold with design professionals and local/regional
governments. This view looks not only at public safety during and
immediately following hazard events, but also at recovery and
resumption of normal activities.
An integrated approach to resilience addresses the
region's most common natural disaster (tornados, hurricanes, or
earthquakes), as well as other hazards like severe weather from a
changing climate, economic shocks, and even new threats like
cyber-terrorist attacks on the electric grid. Most importantly,
resilience and sustainable design strategies should to be
integrated, so investments pay dividends rather than mirroring
insurance models, where premiums are paid, but the insured hopes to
never file a claim.
In last month's
column, we touched on resilience in the neighborhood context
using the EcoDistricts Protocol. Here we will explore the role of
architects in guiding resilience integration for individual
buildings and campus-scale projects. Why resilience? It is human
nature to focus on the tangible issues in front of us and discount
more remote threats, and many owners mistakenly assume new
buildings designed to code will withstand the natural forces they
will likely encounter.
For example, in my state, Oregon, we know a 9.0
magnitude earthquake is likely within the next 100 years. Buildings
designed to current code are likely to remain standing during such
an extreme seismic event, allowing safe evacuation, by absorbing
the lateral forces with their structural frames (the way crumple
zones on cars absorb collision impact). Like the car, though, these
buildings will lose structural integrity and need rebuilding before
they are again habitable. After the 2011 earthquake in
Christchurch, New Zealand, more than 70 percent of downtown
buildings-many built to current code-were demolished after repairs
were deemed cost-prohibitive. Resilient design includes hazard
assessment and continuity planning, building systems enhancements,
and consideration of passive survivability.
Architects can start this process in the programming
phase by asking clients about business continuity planning. What is
the risk posed by potential hazards, what costs could result from
disrupted operations, and how can these costs and risks be
mitigated? If a hazard event occurs (be it an extended power outage
or a major natural disaster), human safety claims top priority. But
afterward, what is needed to keep businesses running? Similar
questions can be asked about disruptive impacts in schools,
government facilities, and even apartment buildings:
- What would it take for a business to remain viable and
contribute to community and economic recovery?
- What small changes would optimize a school's gymnasium to serve
as a comfortable shelter?
- Could a supermarket be designed to preserve perishable food
inventory during a power outage and become an emergency relief
center after a natural disaster?
- What would make an affordable housing project safe enough for
vulnerable populations to stay in place?
The outcome of hazard assessment and continuity
planning will inform both design decisions by the architect and
operational planning by the owner.
With the results of this assessment and planning in
mind, the architect and engineering team can consider building
enhancements designed to mitigate the identified project risks. In
some cases, this might mean a specific design change, like
strengthening the structure above code minimums in earthquake
zones, or locating emergency electrical systems above the ground
floor in flood-prone areas. In other cases, high-performance
building systems can be designed with an emergency operation mode
so they provide operational benefits in ordinary conditions and
also serve essential functions during a hazard event.
For example, a grid-connected PV system can be
designed to switch into islanding mode to provide power for limited
lighting, phone charging, etc., during an extended outage.
Likewise, automated components of a hybrid-natural ventilation
system could revert to manual operation when the power goes out.
Design teams can also consider future-proofing the building. The
project budget may not support the inclusion of on-site energy and
water storage systems; but at little or no cost, provisions can be
made in the building systems to allow a future energy and water
system to be plugged into the building without expensive
Some useful resources for resilient design
In addition to the above enhancements, a third level
of building resilience can be achieved by designing for passive
survivability-maintaining habitable indoor conditions during normal
climate extremes, even when all utilities (electricity, gas, water,
etc.) are out of service for an extended period. Modern, sealed,
air-conditioned buildings become ovens when the power goes out in
summer, but the thoughtful provision of a natural ventilation mode
could ensure indoor temperatures never exceed outdoor temperatures
while mechanical cooling system are down.
When designing for passive survivability, the same
strategies employed for a high-performance, low energy-use building
during normal operations (including daylighting, exterior shading
and enhanced thermal envelope) go a long way toward preparing a
building for habitability after a hazard event. The addition of
advanced systems like on-site renewable energy production and
storage and rainwater collection systems (which provide a positive
return on investment during typical operations) can also be life
saving elements during emergencies. Look for the expected release
of three LEED resilience pilot credits by the USGBC, providing
standards for the concepts discussed above.
The practical consideration of resilient design
begins with asking the right questions. Architects have a great
opportunity to bring these valuable considerations to their
clients, helping to raise awareness and integrate resilience with
other high-performance building design considerations. Architects
can also provide leadership by informing the development of
materials, systems, and design innovations that enhance the
resilience of our built environment. You can find additional
resources on this topic at the American Institute of Architects and the Resilient
Alan Scott, FAIA, LEED Fellow, LEED
AP BD+C, O+M, WELL AP, CEM, is an architect with nearly 30 years of
experience in sustainable building design. He is a director with
YR&G Sustainability in Portland, Ore. To learn more, visit www.yrgxyz.com and
follow Alan on Twitter @alanscott_faia.