In Top Gun, a young-ish Tom Cruise called bars a “target-rich environment” for his principal hobby (let’s call it “dating”). His character, the hotshot Maverick, needed to determine which bar patrons were most interesting to him, so he used some sort of benchmarking tool – probably visual inspection – to determine how his fellow revelers stacked up. Then he could use this internal benchmarking data to figure out his next step. That’s harder to do for building energy use – you can’t always tell just by looking how well a building is performing. We’ve covered many of the ins and outs of Local Law 84 benchmarking here before, and this week’s sold-out technical roundtable brought the latest thinking up for discussion.
It turns out that despite some key differences in skillsets (Maverick: flying fighter jets; intrepid energy auditors: sticking their heads in dusty ducts), energy consultants can do a little bit of what Tom Cruise did. And not all consultants are created equal: Laurie Kerr (now with the NRDC City Energy Project, and an architect of the NYC benchmarking law) said that in the first year of benchmarking, just 30 firms performed 68% of all the benchmarking.
This reduced the benchmarking task “from a million buildings to a few dozen consultants,” as Laurie put it. Looking at the data submitted by this small pool, it came to light that the energy use reported by some consultants tended to be higher than the average. Maybe something was systematically going wrong, like excluding basements from floor area calculations, which would lead to artificially high reported energy use. The city decided to circle back to these consultants in an attempt to improve their accuracy.
When the city sat down with Steven Winter Associates (SWA), there was an interesting development. Roundtable moderator Erica Brabon (SWA), said there was no surprise that the buildings her firm benchmarks had higher energy use than average – they actually specialize in buildings with bloated bills. Why? Because after the benchmarking report is filed, these energy hogs are a target-rich environment, having the most need for follow-up audits and retrofits. Like Maverick, SWA knows exactly what they’re doing.
So in this case the city’s analysis that some benchmarking scores were artificially high was not borne out by reality, but still, score one for Erica as top gun. This is important not just for SWA’s bottom line, but for the city as a whole. According to Laurie, the worst quartile of multifamily buildings are creating almost as much carbon pollution as the entire office sector! Just bringing all NYC buildings up to the current average energy intensity would mean a 20% savings citywide. Laurie thinks that NYC, like Lake Wobegon, shouldn’t stop there: she’d like to see a city where “all of our buildings are above average.”
In some areas, though, we are still trying to understand what the benchmarking data is telling us. For instance, multifamily building energy usage increased for 80 years – but it’s declining in newer buildings. On the other hand, energy usage in offices has gone steadily upwards, to the point where new buildings are now at a level 40% above buildings built before the Great Depression. There may be many reasons for this, including more glass, more ventilation, and more data centers. Portfolio Manager, the tool used to submit benchmarking scores, is supposed to adjust for some usage factors when giving commercial buildings an ENERGY STAR rating, but it clearly can’t explain all the variation. So no one yet knows for sure.
To help understand this, Laurie mentioned a hot-off-the-presses metric that might help account for the range of energy intensity found in modern office buildings. At Greenbuild, Buro Happold/Happold Consulting tried to link tenant contributions to the economy to building benchmarking scores. The more economic activity a building contains (based on the mix of tenants it houses), the more energy use you might expect, since newer, high-end office buildings often contain energy-intensive activities like trading floors and data centers. It’s a worthy addition to the conversation on how building tenants can affect energy intensity. But as Laurie pointed out, it risks being interpreted by some as meaning “a nonprofit can’t use any energy, but a bank can use a lot.” Please don’t take away my laptop!
Throughout the audience discussion it was clear that we are at the beginning of new era of “big data” for buildings. Our tools are far from perfect – but are good enough to get started. While EPA and DOE have work to do to improve our tracking and reporting systems, Laurie says “don’t throw out the baby with the bathwater.” The best of benchmarking is still to come.
This post was edited on December 19, 2013 to better describe the Buro Happold study.