The AIA 2030 Commitment: Metrics that MatterPosted: September 7, 2011
Yes, god help us, we don’t need another acronym. But if your architecture firm signs the AIA 2030 Commitment (and I think it should), you will come to know the PEUI (Predicted Energy Use Intensity) of every one of your projects. PEUI will become your mantra.
The AIA 2030 Commitment is especially attractive to architects because we dislike differential equations. Architects have a hard time doing the math to convert kilowatt hours of electricity used into a quantity of CO2 emitted. Climate scientists talk exajoules of primary resource consumption related to metric tons of atmospheric carbon and normalized intraseasonal oscillation.
No slam intended. If we liked calculus we might be climate scientists. The AIA 2030 Commitment does the math for us. It gives us a simple, useful metric to evaluate all our projects’ energy performance. That metric, Predicted Energy Use Intensity, is measured by a project’s kBtu/sf/yr.
But first, I have a serious bone to pick with the word “predicted”.
Design indicates intent. A new car has an MPG rating that indicates intended – not predicted – fuel efficiency. If that car is driven at 105 miles per hour on underinflated tires and low-octane fuel with the air conditioning on, performance will not match design intent. Same goes for buildings, and buildings are not mass-produced with the quality-control regiment of automobiles. We just can’t consistently predict building energy use intensity today. I suggest calling it DEUI (Designed Energy Use Intensity) except for the obvious similarity to a criminal offense. Or IEUI (Intended Energy Use Intensity). Or how about just EUI, leave the predicting to odds-makers.
But really, the metric that matters is what PEUI measures: kBtu/sf/yr. In order to improve our projects’ intended energy use efficiency we must learn to love the kBtu/sf/yr.
Allow me to play engineer for a moment. Building energy use is usually communicated in terms of raw electricity consumption: kilowatt-hours. This metric doesn’t include other forms of fuel like natural gas or oil, and it doesn’t tell us anything about a project’s efficiency relative to its size. The BTU (British Thermal Unit) is a measure of the energy content of any fuel. Describing building energy use in thousands of BTU’s per square foot per year lets us combine all fuel types into a single, qualitative apples-to-apples design efficiency indicator. Beautiful.
Do you have to do this? Do you have to know the designed energy-use intensity of all your projects? Do you have to love the kBtu/sf/yr? No, but if you want your architectural firm to be part of the climate change solution, this is where you start.
You will be tested on this.