Can good design be affordable and sustainable?
Building design that relies on metrics and performance data will someday be as commonplace as the mile-per-gallon sticker we see when we purchase a car. Consumer-oriented data is commonly used for components of our homes and commercial buildings. By law, home appliances display comparative annual energy use and Energy Star ratings, and many of us know the seasonal energy efficiency ratio (SEER) rating of our air conditioning systems or the efficiency of our water heater. Even if most of us do not thoroughly understand the science behind these rating systems, we understand them in relative terms, such as higher SEER rating = good; lower efficiency = bad. This information helps consumers make educated choices for purchasing longer lasting, better performing products that save money over the product’s lifetime. So why not have this type of data available for the homes and the buildings we purchase to live, work, and create in?
We do have this type of information for use in designing buildings, and it is beginning to get wider visibility by people outside the design community. A key metric is called EUI, or energy use intensity, and it measures the energy used per square-foot of building. While not a universally known metric, EUI is used in a fashion similar to the MPG (miles per gallon) rating used for cars. Although in this case, the smaller the EUI number (energy used per square foot of building) the better, with a lower EUI meaning fewer dollars out of your pocket.
The design community and most building owners/developers continue moving towards the eventual goal of buildings using zero net energy to heat, cool, and operate them, or an EUI value of zero. MSR and other architects and engineers are pushing this evolutionary thinking by relying on data in the design process to help study optimal building shape, massing, orientation, density, access to sunlight and winds, user behaviors that can be passively or actively managed, and other factors that drive the design process. Engaging in a data-driven design process (a.k.a., performance-based design) combines professionally-honed design intuition and expertise in how people interact with space with hard scientific data related to use, localized climate, sunlight, surroundings, building envelope (e.g., roof, windows, doors, and walls), and many other factors. A very rigorous and balanced approach to design, data-driven design relies on high-speed computing and vast databases of information related to every aspect of our built world. Data-driven design allows the design team (e.g., architects, interior designers, and engineers) to advise owners and developers about the optimal combination of design strategies that will result in lower EUI values and a higher ROI (rate of return). We can give owners and developers the tools to make smarter choices about not only energy use, but also systems durability and maintainability for the lifetime of their buildings, which is referred to as life-cycle assessment thinking. Data-driven design generally relies on employing passive design strategies to reduce the amount of energy needed. These strategies help make buildings tighter, using less energy by using more energy-efficient systems and making up for energy use with on-site renewable energy generation. We are probably at least a generation away from creating systems where energy put into a closed system equals, or exceeds, energy out of a system.
A recent project for Aeon, an affordable housing developer in the Twin Cities region, illustrates a way to engage clients in these discussions using a data-driven design approach. Designed by MSR and our partners Karges Faulconbridge, Inc. (mechanical, electrical, and plumbing engineers), Emmons & Olivier Resources (civil engineer and landscape architect), and Meyer Borgman Johnson (structural engineer), these two apartment buildings will realize 72% reductions in total energy use and 50% reductions in water use, recycle/reuse 100% of existing onsite trees and concrete (left from buildings demolished on the site and old sidewalks in very poor shape), feature dwelling units that are 100% free of toxic ingredients found in the most commonly used building products in the U.S. With an anticipated cost of $148/sf and targeted to meet an EUI value of 30.5, the project will substantially reduce tenant utility costs and provide an attractive, vital community and great long-term asset.
Good design can be affordable and sustainable. The data-driven design process enables design teams to model all aspects of a building during design to optimize them relative to one another, much like how cars are designed. Using such an approach is the only way to eventually drive EUI values down to zero and achieve lasting American energy independence.
To learn more:
This brief article, “Energy Intensity Indicators,” by the U.S. Department of Energy discusses the relationship between energy intensity and energy efficiency: two very important measures
The Rocky Mountain Institute website is a repository of information on energy efficiency and related topics.
And this feature on BuildingGreen.com discusses Aeon’s Rose Housing project in more detail, specifically addressing how to achieve Living Building Challenge standards on a super-tight budget.