Green building (ac)countability?

Last week at the NESEA Building Energy10 Conference, I attended a session called Counting Measuring Reporting: what's important? where architect Chris Benedict instigated a really interesting conversation about standards, scientific evidence, and accountability for energy efficient buildings.

The premise of the session was simple enough: NESEA is developing a database of energy efficient buildings - a resource for architects, builders, clients, etc. that will include a series of case study projects, providing information about the green design elements of each as well as supporting post-occupancy energy data. ["Post-occupancy data" is collected after the building is built and people are using the space. For the record, it is not uncommon to see a pretty sizable difference between the projected building performance, simulated in the design phase by architects and engineers, and the actual "post-occupancy" energy data.]

Anyway, the NESEA database will offer a way of comparing various green strategies, systems, and products to begin to determine how they actually function in practice. In order to create such a tool, Benedict, working on behalf of NESEA, is in the process of deciding what aspects of the buildings, exactly, ought to be measured, recorded, and collected. In the session, she presented a draft of a questionnaire designed to collect this information and solicited the audience for feedback.

Simple enough, right?

Wrong.

What ensued was a pretty fascinating [and occasionally heated] debate about how and what should be measured by whom and what it all would, could, and should mean to the industry. If you're thinking to yourself "how could that conversation possibly be interesting and/or controversial?" Let me see if I can summarize a couple of the key issues for you here:

1. There is a lack of agreed upon standards. For example, energy is sometimes measured in Btu's, sometimes in kWh. Square footage is sometimes calculated from the outside edge of exterior walls, sometimes from the inside; some people include auxiliary spaces or unfinished basements; some people prefer to use the R-value [a measure of thermal resistance, or insulation effectiveness] specified by product manufacturers, while others insist that the "actual" measured R-value of the built wall system should be recorded. You get the idea.

2. Energy performance in buildings is difficult [and expensive] to measure. We are not talking about experiments conducted in the confines of a controlled laboratory space. Buildings are huge and complex, involving many complicated systems operating at the same time, each of which has its own error in measurement. To make things even more complicated, buildings are inhabited, operated, and modified by real people who often don't follow [or even know about] the architect's/engineer's/builder's recommendations. For example, simulated energy performance might be based on an assumption that the thermostat will be kept at 65 degrees F. If someone in the building gets cold and turns it up to 73 and then someone else gets hot and opens a window, "post-occupancy" data will show the system to be considerably less efficient than predicted. Due to the complexity of large buildings, not to mention the interference of those pesky human occupants, it's very difficult to know the precise reason for a building's energy success or failure.

Anyway, what I find interesting about all of this is that it seems as if Architecture, before our very eyes, is in the process of becoming a science. Its practitioners are engaged in an ongoing debate that, while it may seem mundane and nitpicky on the surface, actually involves some pretty fundamental questions about how we know what we know and what we should do with that information.

Despite the debate about how and what to measure, the BuildingEnergy10 attendees definitely seemed to be in agreement about the fact that measuring is important. It will, as the argument goes, provide quantitative data about which systems are more efficient, help people in the field to standardize research efforts and learn from each other, and offer an alternative way of thinking about cost effectiveness. Instead of "cost effective" being thought of in terms of payback, with the right measurement tools, it can be thought of in terms of meeting specific environmental benchmarks.