These charts provide an overview of energy and emissions data across all
large buildings tracked in the city. Explore trends over time, compare
building performance, and identify opportunities for sustainability
improvements.
Important Note! 2019 data is impacted by COVID, because
data is reported on a delay. A large number of buildings didn't report
their 2019 data, and so some statistics may have varied. To learn more,
see our article:
Do High Emitting Buildings Report Emissions Less Often? , where we have a clear graph of the COVID reporting shifts.
Median GHG Intensity (kg CO2e/sq ft)
Buildings are responsible for about 40% of global greenhouse gas emissions, making them a critical piece of the climate puzzle. GHG intensity shows how much climate pollution a building produces per square foot of space (measured in kg CO2e/sq ft).
Think of this as your building's carbon footprint per square foot. To put this in perspective, the annual emissions from each square foot of a typical commercial building can be comparable to driving dozens of miles in a gas car — but that impact is happening for every square foot of the building, every year.
Lower intensity means the building is either more energy-efficient or using cleaner energy sources. This metric helps level the playing field between a small café and a massive skyscraper.
Median GHG Emissions (metric tons CO2e)
This tracks the total climate impact of buildings — all the greenhouse gases they produce from electricity, heating, and cooling combined. Every kilowatt-hour of electricity and every therm of gas burned adds to a building's total emissions.
One metric ton of CO2e equals about 2,000 pounds* of carbon pollution — roughly what a typical gas car produces driving 2,500 miles. A large Chicago office building might emit hundreds or even thousands of metric tons per year.
Unlike intensity metrics, total emissions show a building's absolute climate impact. A highly efficient skyscraper might still have high total emissions simply because it's massive, while an inefficient small building could have relatively low total emissions.
Median Electricity Use (kWh)
Electricity powers everything in modern buildings — lights, computers, elevators, air conditioning, and increasingly, heating and hot water too. As more buildings electrify to reduce emissions, understanding electricity use becomes even more important.
One kilowatt-hour (kWh) powers a desktop computer for about 3-4 hours, or runs your microwave for an hour. A typical Chicago office building uses thousands of kWh daily — enough to power hundreds of homes.
The climate impact of electricity varies dramatically based on the energy source. In Illinois, where about half our electricity comes from nuclear and renewables, each kWh produces less emissions than in coal-heavy states. This is why electrification can be a climate win.
Median Fossil Gas Use (therms)
Fossil gas (often called "natural gas") is the biggest source of building emissions in Chicago. Most buildings use it for heating, hot water, and cooking — and every therm burned releases carbon directly into the atmosphere.
One therm equals about 100 cubic feet of gas and produces roughly 11 pounds of CO2 when burned. A typical Chicago building might use hundreds or thousands of therms during winter months. That adds up fast when you consider the city's long, cold winters.
Unlike electricity, which can get cleaner as the grid adds more renewables, burning fossil gas will always produce emissions. That's why many climate strategies focus on electrifying heating and switching to heat pumps, electric water heaters, and induction cooking.
Median Source EUI (kBtu/sq ft)
Source EUI captures the total energy demand a building places on our energy system — not just what shows up on the utility bill, but including all the energy lost generating and delivering that power to the building.
For every kWh that reaches your building, about 2-3 kWh of primary energy was needed at the power plant due to conversion and transmission losses. One kBtu is roughly the energy in a wooden kitchen match — buildings typically use tens of thousands of kBtu per square foot annually.
This metric matters because it reflects the true demand buildings place on our energy infrastructure. A building with high source EUI is straining the broader system more, requiring more power plants, gas wells, and transmission lines to support it.
Median Site EUI (kBtu/sq ft)
Site EUI measures the energy actually delivered to and consumed by the building itself — what you'd see on your utility bills. This is the most straightforward way to understand how much energy a building uses per square foot.
A well-insulated, efficient building in Chicago might use 50-80 kBtu per square foot annually, while an older, inefficient building could use 150+ kBtu per square foot. That's the difference between a warm sweater and a thin t-shirt in a Chicago winter.
Site EUI is the go-to metric for comparing building performance because it's directly tied to what building owners can control — insulation, windows, HVAC efficiency, and occupant behavior. It's also what most energy benchmarking programs use to set targets and requirements.
