Written by Jim Lindberg
Can a 125-year-old school be rehabilitated to meet or exceed the highest standards for energy efficiency and sustainability? Without sacrificing historic character? Yes, absolutely! That was the consensus of a group of 35 architects, engineers, contractors, preservationists and green building practitioners who gathered at Denver’s Emerson School earlier this week for a day-long “Eco-charrette.”
(For the uninitiated, a charrette is an intensive design workshop.)
The Emerson School was recently donated to the National Trust for Historic Preservation. Work is now underway to design and implement a $2.4 million rehabilitation of the school to create a new Colorado Preservation Center, housing the National Trust’s Mountains/Plains Office, Colorado Preservation, Inc. and Historic Denver, Inc.
The Eco-charrette was facilitated by Ralph DiNola, a principal with Green Building Services in Portland, Oregon. His charge to the group was to look into the future and set a vision for energy performance and sustainability at the Emerson School and then work backwards to chart a course for how to get there.
The result was an aspirational, long-range target of reducing energy consumption at the Emerson School to “netzero” by 2030. The short-term goal is to cut energy use by 50% within two years. Both are ambitious goals, but attainable in the view of most of the charrette participants.
As with many existing buildings, immediate energy savings can be achieved by “picking up the fruit that is on the ground,” as Ralph DiNola described some of the easiest initial measures. These include insulating the attic, tightening windows and doors to eliminate leaks, and making thermostats operable (so that rooms are not heated to 85 degrees while sitting empty overnight, for example). Other energy savings will require more substantial investment, such as the overhaul of the school’s heating and cooling systems.
A key theme throughout the day was to consider ways to use the passive energy-saving features of the original building design, such as operable windows and air ventilation stacks that are built into the central chimneys. Making full use of these features may require future occupants to participate in the operation of the building -- opening and closing windows, drawing shades or switching on fans strategically, for example. “We need passive buildings and active users” observed charrette participant Elaine Adams of the Rocky Mountain Institute. (Historically, much of this work was carried out by a full-time building manager who lived in the basement of the school! More on that in a future post.)
The group also determined that additional analysis, such as a building energy model, is needed to answer a number of key questions, including:
- What kind of heating and cooling system will best complement the use of natural ventilation?
- What window repair strategies make sense? Should double-glazing or low-e films be added?
- Should energy-producing technologies (solar, geothermal) be incorporated? Now, or later?
- How can interior spaces be rehabilitated to take advantage of daylight, while also allowing for privacy and efficient office layouts?
- What energy efficiency and green building certifications should be pursued, if any?
Thanks to the great work of our charrette participants, we now have an inspiring vision for how to make the Emerson School a model of sustainable design. Look for future posts on our progress toward this vision as well as more on the interesting history of this great old building.
A final note: We are just getting to know the Emerson School. The charrette was our first opportunity to spend a full day in the building. We liked it. Our meeting was held in a former classroom on the second floor. We enjoyed the feeling of the space, with its high ceilings and great views out large, south-facing windows. These windows kept the room bright enough that we didn’t need electric light until the very end of the day, when a snow-squall darkened the sky just before sunset. We didn’t need to turn on the heat either, despite outside temperatures that dropped to near freezing. (Of course we were lucky it wasn’t too much colder, since the heat in this room doesn’t actually work!)
Jim Lindberg is the director of preservation initiatives for the National Trust’s Mountains/Plains Office.
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