Guest Post - Biomimicry: A New Tool for Building Preservation
PVN presents this guest blog post by Patrick Doss-Smith, LEED AP. Patrick is interested in the overlap of historic preservation and sustainable design. In this post, he discusses the practice of biomimicry, and how it could be utilized in the field of preservation.
In November of 2012 I presented on the subject of Sustainable Preservation at the fall conference of the Western Great Lakes Chapter of The Association for Preservation Technology. The talk and slide show was given at the School of the Art Institute of Chicago and can be downloaded from my LinkedIn profile.
So what is Biomimicry and how can it be applied to building preservation? The name Biomimicry 3.8 refers to the 3.8 billion years that life has been designing itself. The website primer of the Biomimicry 3.8 Institute puts it like this:
Biomimicry is learning from and then emulating natural forms, processes, and ecosystems to create more sustainable designs. It’s studying a leaf to invent a better solar cell or a coral reef to make a resilient company. The core idea is that nature has already solved many of the problems we are grappling with: energy, food production, climate control, benign chemistry, transportation, collaboration, and more. Mimicking these earth-savvy designs can help humans’ leap-frog to technologies that sip energy, shave material use, reject toxins, and work as a system to create conditions conducive to life.
In the built environment there are many examples of just how long a building can last given locally appropriate construction techniques, proper maintenance, and the social will for preservation. Yet it is a relatively short period of time that we have come to value the beauty and diversity represented by our historic building stock. Even more recent is the idea that historic preservation can be a powerful tool in the effort to transform our economy toward a more sustainable ethic. The interconnected systems based approach emerging from the practice of sustainable design is well suited to exploring what there is to be learned from the embedded culture inherent in old buildings while also having the flexibility to look inward at the working of ourselves and our environment. In that spirit this posting suggests opportunities for adopting the principles of biomimicry as a tool for historic building stabilization.
It is not uncommon to see buildings sit empty while they await the right development team or an appropriate community use. Without active monitoring and maintenance some of these edifices quietly crumble, becoming victims of demolition by neglect. Municipalities or small communities may lack local tools or policies to prevent the loss of vacant or unmaintained historic resources, placing the fabric of the community at risk. Interim stabilization and monitoring allows for the resource to be preserved until future opportunities arise. The National Park Service’s Preservation Brief 31: Mothballing Historic Buildings provides a good basic plan that can be used on any building. The paper defines the following nine steps:
- Document the architectural and historical significance of the building.
- Prepare a condition assessment of the building.
- Structurally stabilize the building, based on a professional condition assessment.
- Exterminate or control pests, including termites and rodents.
- Protect the exterior from moisture penetration.
- Secure the building and its component features to reduce vandalism or break-ins.
- Provide adequate ventilation to the building.
- Secure or modify utilities and mechanical systems.
- Develop and implement a maintenance and monitoring plan for protection.
Biomimicry can offer strategies and tools that can support many aspects of preservation, including the mothballing process. To illustrate this, I will present examples of applying biomimicry to mothballing. I will focus on two of these steps above: providing adequate ventilation, and developing and implementing a maintenance and monitoring plan.
Biomimicy 3.8’s Ask Nature webpage, a free, open source project, is where I started my search for ideas that biomimicry could bring to the mothballing process. Over 1,500 biomimetic strategies are presented in categories such as ‘Break Down’, ‘Make’, ‘Modify’, and ‘Process Information’. Under the category of ‘Maintain Physical Integrity’ are five sub-categories from which I chose the following three natural processes and some possible biomimetic strategies.
It turns out that the Hercules Beetle, Dynastes Hercules, has an exoskeleton that changes color under differing humidity conditions. To put it briefly, the exoskeleton is built in three layers with the middle being composed of nano-scale holes which either fill with water or air, giving them differing reflective properties. Researchers at Sogang University in South Korea are in the development phase for a humidity sensor that operates without electricity and utilizes nano-scale technology to mimic the beetle’s exoskeleton structure, which could have useful applications in a mothballed building while requiring minimum expense. For example, as part of a monitoring system it could alert a caretaker when and where humidity control was required, reducing time spent on site observations. Even simpler, a color changing strip of paint, placed on vulnerable wood members could be monitored during periodic walkthroughs, minimizing the need for expensive testing equipment.
My second example comes from one of my favorite animals, the spider. The dragline silk in a spider’s web expands and contracts in response to moisture, allowing the web to avoid collapse under rain or dew conditions. Researchers at the University of Akron liken the silks to muscle fibers and are developing a concept for humidity responsive fibers from the idea. Such fibers could be developed into a microswitch to actuate a vent fan or open a passive vent in conjunction with the stack effect; warm air carries more moisture.
My final example also involves moving parts and comes from the common Horsetail Fern, of the family Equisetacea, which disperses spores via many tightly fitting, polygonal scales attached to a central axis. During ripening the central axis elongates, separating the scales and exposing several yellowish sporangia which in turn dry, split open, and release the spores. The spores windborne journey is aided by devices called elaters that uncoil as they dry, acting like sails, and recoil when wet, allowing the spore to drop, hopefully onto moist soil. This expansion and contraction again suggests application within a microswitch technology to turn a solar vent fan on and off or to send a signal from a monitor, reducing or eliminating the need to maintain electrical service. Or perhaps a mechanism that mimics any of the three strategies could be used to release color within a moisture laden area, simplifying leak detection or allowing timely mold control.
All of these strategies have the potential to reduce the costs associated with rehabilitating buildings damaged from moisture infiltration, including eliminating toxic chemicals associated with remediation of mold, and the high levels of waste during remediation as well as potentially high labor costs of repairs and monitoring; all of which make it harder to save a vacant building. While I am focusing on mothballing vacant buildings, biomimicry has many possibilities that are being developed and can be explored that can make any building more responsive to the local microclimate, more energy efficient, and less expensive to operate and maintain.
Sustainable building design asks that we consider buildings as integral to the larger, interdependent systems that sustains life, the ecosystem, and the economy. Therefore, buildings both effect and are affected by those systems. Preservation is at the core of creating a sustainable built environment and by extension a sustainable society. By preserving and improving what we already have, we prevent tears in the fabric of our cities and neighborhoods just as sustainable design strives to prevent and heal damage to the environment. The current blending of the fields of preservation and sustainable design is a positive development and deserves the attention of the designers and researchers working to create a new, low energy economy based on new ideas and not simply trying to make business as usual more efficient.
To paraphrase Michael Braungart and William McDonough, creators of the Cradle to Cradle philosophy, “Doing less bad is not doing good.” Thus, keeping historic buildings alive while they await future redevelopment opportunities requires more than boarded up windows: a proactive approach is needed to creatively apply low energy tools to help historic buildings to breathe, stay tempered, and continue to provide beautiful places to live and work!
I’d like to close with a final thought from Janine Benyus. In her talks she often reminds the audience that biomimicry is the conscious emulation of life’s genius. She is referring to our conscious intent as the designers of where we live: it is not enough to design something beautiful and useful and then only notice that it reminds us of nature as an afterthought - nor is it enough to follow nature’s lessons in isolation from the rest of our designs, processes and policies. She further implies that to emulate is not simply to copy a mechanism or product, but also to understand the larger role being fulfilled. Finally, she reminds us to see life’s genius as more than cleverness. It is the spark of insight in response to earth’s mandates.
Patrick Doss-Smith, LEED AP, email@example.com