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Is Your Home A Lemon?

by on July 30, 2018

Cornell University Researcher Dr. Howard Chong studies “leaky” homes

Is your home a lemon?

Dr. Howard Chong at Cornell University has developed a simple test to find out, using ecobee’s Donate Your Data program.

North America represents wildly diverse populations, housing stock, and climate zones. Every single house – even two houses next door to each other – will use energy differently based on a variety of factors. Who lives there? What do they find comfortable? How much space needs to be heated and cooled? How old is the roof? What condition is it in? How old are the windows? Who built the house, and when?

Dr. Howard Chong, environmental economist, engineer, and associate professor at Cornell University, says yes.

“Cars go through incredible diagnostic tests,” he points out, “homes do not get the same scrutiny.” With our cars we can find out, at a glance, whether our car is low on fuel, needs air in its tires, or how efficiently it’s spending fuel. Houses don’t have the same kind of easy-to-understand dashboard tool for energy performance.

We, and our homes, deserve a lot more. In fact, using the Donate Your Data set, his research has verified what he, and many homebuilders and homeowners, have long suspected… building codes aren’t working as well as they should.

“Variation in utility bills may be influenced by behavior,” Chong explains, “but the Donate Your Data set is confirming that it’s also whole home performance leading to those variations, not just behavior.”

So how do you find out if your home is a lemon?

Chong has devised a leaky house test: a simple, straightforward model that produces a score for your home and indicates how effective it is at retaining heat. The test produces a “leakiness” score—the higher the score, the leakier your home is.

It works like this: in fall or winter, homeowners turn on their heat to their preferred comfort levels, and, after reaching the desired temperature, turn it off for a set amount of time. Chong’s test measures how long it takes for the temperature inside to drop. If it drops very quickly, it’s as though your house is wearing a thin, loose-knit sweater.

If it drops slowly, it’s as though your house has a snug, 100% cashmere sweater on. That’s the kind of efficient coziness we all want for our homes in the winter.

This is where Donate Your Data elevates Chong’s research. Because ecobee smart thermostats are being programmed by thousands of customers for “Home” and “Away”, and to track indoor temperature changes, Chong can model leaky house tests on thousands of homes by simply looking at the data set.  He can compare home performance by region and neighborhood, which could be matched against varying building codes and age of housing stock. In short, he can spot the lemons.

So how does that help the rest of us?

The benefits of research like this apply across the spectrum.

For homebuilders and regulators, Dr. Chong can provide a snapshot of home performance across North America, and demonstrate differences across neighborhoods, climate zones, and regions. He can help builders and regulators understand how codes are operating in practice.

This also means a future of empowered homeowners who can understand their individual home performance in simple, straightforward terms. Imagine being able to make decisions about your home improvements based on its “leaky” score.

But not everyone has access to the right information as well as the financial resources to inform improvements to their home. With that in mind, Chong makes a point that really hit home:

So how do we reach these homeowners? And if we do connect with them, how can we help them access the benefits of ecobee technology, and help them begin their own energy efficiency journey? That insight drives ecobee’s commitment to work with public housing and income-qualified communities and organizations (see more about that here).

Advancements in research like Dr. Howard Chong’s are amplified by none other than real ecobee users through the Donate Your Data program. These are real homeowners and leading researchers working together to inform how we can live more sustainably.

If you’re interested in getting involved, or learning more, visit