Mar 28, 2018
By Ann Edminster, M.Arch., LEED AP, www.annedminster.com
On February 23, roughly 2,000 North Bay residents attended the Rebuild Green Expo in Santa Rosa to learn about options and strategies for rebuilding a greener, healthier, more sustainable and – perhaps most importantly – a more resilient community. All those terms (green, healthy, sustainable, resilient) are pretty squishy; what do they mean? While there are probably as many definitions as there are green building practitioners, I’ll draw from just a few of the education sessions offered at the Expo to help describe some of the potential outcomes and benefits from adopting a green and resilient approach to rebuilding.
Some materials are inherently greener than others – for instance, by eliminating toxic chemical ingredients or reducing the ‘embodied energy’ (and greenhouse gas emissions or ‘embodied carbon’) resulting from their manufacture, in comparison with their conventional cousins. Some typical building products for which greener alternatives exist are insulation, paints, flooring, and adhesives. Many spray foam insulation products, for example, have very high global warming potential and should be avoided. Concrete contains cement, which is high in embodied energy and carbon; however, the cement content can be reduced by replacing some of it with fly ash, a waste material. Green Building Advisor is an authoritative website offering many articles, product reviews, and other resources to help in selecting greener materials.
Almost anything will burn if the fire is fierce enough, but there are ways of building structures and landscapes that can make them less vulnerable to fire spread. Steve Quarles, chief scientist for wildfire and durability at the Insurance Institute for Business & Home Safety, provided expert advice about specific building details to incorporate in new home designs. Risk reduction measures include designing roof venting to avoid spark intrusion, choosing more fire-resistant exterior materials, and minimizing the amount of fuel in the surrounding landscape.
here is a widespread belief that building ‘green’ means spending more green. That’s certainly true when the green aspects of a design are add-ons or afterthoughts. But when green is ‘baked in’ from the beginning of design – which happens automatically with an experienced, green-savvy architect – it’s simply factored into the normal design process and accommodated within the project’s budget.
Design is always a process of trade-offs, so this is accomplished by prioritizing cost-effective performance and comfort strategies, for example, over more superficial (and often costly) ones such as complex roof designs – which compromise energy performance, comfort, durability, and rooftop energy production, while adding significantly to costs. PG&E has published a detailed report on a zero net energy (ZNE) demonstration home in Stockton built by Habitat for Humanity that adopted this approach; the report is available as a free download.
My concerns about climate change prompted me to write Energy Free: Homes for a Small Planet in 2009, to help accelerate the adoption of ZNE design and construction. A ZNE home produces as much clean, renewable energy as it uses over the course of a year. There are two key ingredients to ZNE: a highly efficient building and a rooftop photovoltaic (PV) solar energy array. The PV array is undeniably the sexier of the two; the core value of ZNE, though, lies in its efficiency. This means whether or not a PV system is installed right away, a ‘ZNE-ready’ home will have low energy bills, will maintain comfortable temperatures more easily in weather extremes (and power outages), and will put less stress on the community’s electric grid.
Widespread adoption of ZNE in the North Bay can reduce energy demand significantly, and thus contribute to a more stable grid. The next step – going all-electric – can further contribute to a more resilient, stable local power system by enabling the elimination of dangerous, leaky, natural gas infrastructure that is difficult and costly to maintain and caused fires to continue burning long after from the structures were burnt to the ground. An efficient, all-electric community reduces risks and can be powered by 100 percent clean, renewable energy – much of it locally produced and supporting the local economy.
There are numerous case studies demonstrating that it is possible to build a ZNE or high-performance home at no cost premium, yet many people are nevertheless concerned about a perceived ‘green premium.’ In order to ease the adoption of green practices and help offset the enormous economic losses suffered by North Bay residents, Sonoma Clean Power, PG&E, and the Bay Area Air Quality Management District have teamed up to offer a joint incentive program, scheduled to launch in early May, to encourage homeowners to incorporate more high-performance energy features in their new homes.
The incentive structure consists of two tiers – $7,500 for building an “Advanced Energy Home” (20 percent more efficient than the building code requires), or $12,500 for making that ‘advanced’ home all-electric – and in each case installing an electric vehicle charging station (free from Sonoma Clean Power). On top of either tier, an additional $5,000 is available if the home includes both a PV system and a battery, or if the homeowner commits to purchasing 100 percent local renewable power for 20 years.
Visit www.rebuildgreenexpo.com and www.ecobuildnetwork.org/projects/rebuild-green-expo for more green building ideas, resources, and experts who can help with your rebuilding project.
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