Why Arc Scores

Chris Pyke
Published on
Wednesday, March 6, 2019

Scoring is central to the Arc platform. It is worth stepping back and asking why Arc is focused on scoring. Arc scoring has three primary motivations: simplification, differentiation and flexibility.

1. Simplification

Arc is based on the idea that the future of green building is rooted in measuring the operational performance of buildings, portfolios and communities. The idea is that measured, real-world performance will gradually replace documentation as the basis for recognizing high-performing green buildings and places. Ultimately, this is driven by our desire to ensure that green buildings consistently deliver real-world results.

In fact, we want the definition of green building to be a building that delivers real-world performance — that is better for people and the environment. Arc supports both of these dimensions. For example, the human experience in and around buildings reflects many performance dimensions, including thermal comfort, daylight, odors, noises, vibrations, chemical exposures and much more. Similarly, we have many ways to measure environmental performance, including total energy use, peak demand, energy use intensity and more. Scoring provides a way to aggregate and simplify this kind of multifaceted data into something we can understand and act on. In the case of Arc, this means an easily understood score between 0 and 100.

There is both an art and a science to scoring. The art of scoring comes first. This may be surprising, since on the surface, scoring looks like math. However, scoring starts with specific goals and values. In the case of Arc, the goal is to use operational performance data to assess the degree to which spaces, buildings and places provide superior conditions for people while protecting the environment. Evaluating this concept involves assigning weights to specific performance dimensions. In other words, there is no scientific way to assign a definitive relative importance to, say, greenhouse gas emissions vs. toxic exposures vs. stormwater runoff. We deal with this by turning our values into quantitative weights-expressions of the relative importance of issues and impacts.

Once values have been expressed, we get to the science of scoring. The science involves selecting the most concise set of practical metrics to represent each area of performance. Further, it involves making a myriad of increasingly granular decisions regarding how metrics are defined, measured, analyzed and interpreted. For example, we need to decide whether we measure occupant satisfaction on a 0 to 5 or a 1 to 10 scale, or, alternatively, if we measure CO2 concentration every year, month, day, hour, minute or second. Fortunately, we can analyze these alternatives and look for strategies that best represent different dimensions of performance.

At the end of the day, scoring brings together both art and science to provide a concise description of performance. It hides — but does not eliminate — the underlying complexity in a way that makes information understandable and actionable.

2. Differentiation

Scores are always a simplification. We can all relate to this in concept. We know that scoring a “B+” grade in high school Spanish reflects an exhausting collection of tests, quizzes, homework assignments and more. I have described how this simplification works and to a degree why it is necessary. The next critical issue is whether the score is useful. For me, the most fundamental test is whether a score meaningfully differentiates what we are trying to evaluate. In the case of Arc, we are trying to differentiate spaces, buildings and places by the degree to which they actually provide superior conditions for people, while protecting the environment.

This means that the value of an Arc score is reflected by the degree to which a high score (100) is meaningfully different from a low score (0). A high quality score makes these distinctions visible and actionable. For Arc, this means that a high-scoring space, building or place has low greenhouse gas emissions relative to its peers. It also saves water, reduces waste and provides a satisfying indoor environment. It is equally true that a low-scoring building has higher emissions and is relatively lower performing with respect to water, waste and human experience.

At the highest level, an Arc score is valuable because higher scores differentiate better spaces, buildings and places from lower-scoring peers. We affirm and test this in two ways. First, the score is fundamentally designed so that high performance spaces, buildings and places receive high values. This is an intrinsic characteristic of the rules governing the score. Higher scores go to projects with complete data that demonstrate superior performance across multiple categories. Second, thousands of real-world projects have received Arc scores. So we can look at the characteristics of these projects and see where people report high levels of satisfaction and where data shows low levels of energy use and emissions related to peers.

3. Flexibility

The last essential element of scoring is flexibility. This might be a little less obvious. Arc provides a hierarchical structure linking multiple measures of operational performance to performance categories and ultimately to an aggregated score. One benefit of this structure is the ability to swap or change individual performance measures, while maintaining higher level categories and scoring. For example, Arc has tools to assess transportation behavior. Today, the primary tool is an occupant survey. This is simple and reliable. However, in the future, it might be possible to substitute transportation information based on an app or cellphone-based tracking. This might provide more reliable information, while reducing the need for responses from individual occupants. Arc’s structure allows us to swap the transportation survey with a future travel app while still expressing the transportation score in terms of 0 to 100. This is a great feature since it creates the potential for a “plug-and-play” relationship between individual performance metrics, while preserving the overall scoring structure. The structure provides the flexibility for the basis for this calculation to evolve over time.

Importantly, Arc can calculate any number of scores for a given project or portfolio. In other words, one project can be scored in many different ways at essentially zero marginal cost. Another score is just another attribute of a space, building or place. In the future, this flexibility may enable users to create custom scores that reflect their values and priorities, as well allowing for rating systems like LEED to change scores over time while providing consistency for comparison.

So, why does Arc score?

So, “Why does Arc score?” The bottomline answers are clear:

  • Scoring simplifies a large amount of diverse information.
  • Scoring differentiates spaces, buildings and places based on operational performance.
  • Scoring provides flexibility to evolve and change over time.

We are excited for Arc to provide these capabilities for all buildings and to contribute to a new generation of performance-based market transformation tools to benefit people and environment.