Measuring Up
“If you can’t measure it, you can’t improve it.”
- Peter Drucker
“Leadership is doing the right things.”
- Peter Drucker
Measuring is an ancient art.
Probably as old as humanity itself. Mass and length were most likely the earliest measurements that humans understood, and they became the basis of our economic systems. How big and how much an object weighed helped define its value. We know that grains, seeds, and legumes were used as standard units of measurement in India as early as 600 BCE. Humans now use a plethora of different metrics to measure everything from the largest to the smallest objects in the universe.
Buildings land somewhere in the middle of that spectrum, and as architects we are very good at measuring pretty much anything and everything within the broadest definition of architecture. We still measure length and mass, but over generations we’ve added to our measuring toolbox. Decibels, rentable and usable square feet, degrees, dollars, lumens, joules, BTU’s, perms, double rubs - and grains! - are just a few. Part of learning this business is understanding which metrics to pay attention to and which to leave to someone else. Unfortunately, one key metric architects have neglected for too long, with measurable global climate ramifications, is the energy performance of the buildings we design. It’s past time to actively measure that energy use in an effort to improve a building's performance both for the benefit of our clients, but also to do our critical part to combat the ever intensifying impacts of climate change.
In 2021, RoehrSchmitt Architecture will sign the AIA 2030 Commitment, pledging to target 2030 Challenge goals in all of our design projects and report our progress annually to the AIA.
To do this effectively, we need to be able to measure the energy performance for our projects, past and future. We have the tools to model estimated energy use during the design process, and the means to measure the energy consumption when the building is complete. What is the difference between theoretical and actual? The comparison between the two illuminates the shortfalls, the gaps, and the opportunities. The differences between the modeled performance and the actual building performance should teach us how to improve our buildings - how we can get closer to meeting the 2030 Commitment for the projects we design in the future.
The metric used to describe energy consumption is the Energy Use Intensity (EUI) of the project. This metric is the industry standard for understanding the energy efficiency of any given building and how it relates to baseline buildings of similar use type. The metric is not size-based as it is calculated per square foot, which allows buildings with similar uses to be compared on an apples-to-apples basis, regardless of their size. A bank and a fast food restaurant may use the same amount of space - but have radically different rates of energy use.
We can start with a simple formula. To calculate EUI, divide energy consumed over the course of a year by the building's floor area. Of course, as a smooth wall belies the details beneath, it only gets trickier from here.
First, we need common units of measurement for any formula to work as intended. For EUI, all of the different energy sources must be converted into British thermal units (BTUs) or gigajoules (GJs). For example, it takes 10,000 therms of natural gas to produce a BTU, while every kilowatt-hour of electricity must be multiplied by 3,412 to create a BTU equivalent.
We also need to understand the distinctions between Site EUI and Source EUI. EUI can be expressed relative to either site or source energy. So what’s the difference? Site energy is the term most often referenced in the design community, and in simple terms, Site EUI is the energy consumed at the building site and reflected in the utility bills paid by the owner. Source EUI is a more accurate representation of a building’s energy footprint, as it considers the site energy as well as the energy consumed in moving materials to the site so that the building can be built, and the energy used in actually building the structure. For the purposes of the 2030 Challenge, Site EUI is the metric of choice because it can be difficult to accurately quantify Source EUI, given the complexity of constructing a building.
The biggest challenge to this process may be consistently gathering the information so that we can learn from the data. What’s our system? Will clients be willing - or able - to share the information as frequently as we need it? One idea is to entice our clients to share the information by providing them with an annual report that outlines the annual energy use as compared to the original energy modeling and provide them with suggestions for how they might improve the efficiency of the building or make them aware of significant changes to energy use throughout the year. But without regulatory incentives for clients to actually make use of the data we can provide, are we shouting into the wind?
Another challenge, for RoehrSchmitt in particular, is how the 2030 Challenge relates to existing buildings. Adaptive reuse is a cornerstone of our practice, and understanding how the buildings we restore and revitalize compare to new buildings of similar use is crucial.
It’s a complicated knot to untangle. In Minneapolis, we recently completed a 5000 square foot commercial kitchen and cafeteria addition to a 100,000 square foot elementary school. Our design is thoughtful in terms of exposure and high performance construction, but existing construction for the building consists of an original structure dating to the 1920’s with several additions, the most recent of which was built in the 1990’s. If we report the Site EUI for the entire building, those numbers will mostly reflect the construction flaws inherent in the original building and subsequent additions, but measuring the addition alone is disingenuous and likely improbable.
We know that repairing and continuing to use existing buildings is one of the best things we can do to impact embodied carbon. As Carl Elefante, FAIA once famously remarked, “the greenest building is...one that’s already built,” but given the 2030 Challenge’s use of Site EUI as the standard metric for reporting, how can we account for the benefit of reuse rather than the simpler task of reporting on new buildings? And how do we effectively improve what we cannot yet measure?
“Like water and energy, existing buildings are a resource to be used purposefully and managed.
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What’s clear, however, is that we cannot wait for every question to be answered and every anxiety to be soothed. We’ll start where we can: at the beginning. We’re learning how to measure. We’re strategizing. We’re putting in place firm wide practices for energy modeling with new designs. We’re starting the conversations with our clients about what energy measurement looks like - and where it can take us.
It’s a new, challenging venture in our practice, but we’re excited. We know that when we focus our attention on any issue, we improve. As an architecture firm, we have some amount of control - a measurable amount - over a major contributor to the climate crisis, and as such, a responsibility to act. It’s the right thing to do. And we might be able to answer some questions along the way.
