When Dove Karn bought a rundown old house in Margaretville, New York, last summer, she saw an opportunity to turn a drafty space into an energy-efficient one.

For Karn, a public-school teacher who is involved in a regional climate educational program, the nearly 120-year-old house became an opportunity to implement some of what she’d learned about energy conservation.

“I need to live what I’m teaching,” she said.

We may point to the cars parked in our driveways as good indicators of the size of our carbon footprints, but we should be looking at our houses, too. The average U.S. household consumed nearly 90 million British thermal units, or BTUs, in 2009, nearly 50% more energy than the average car uses in a year, according to the Energy Department. Nearly half of that energy was used to heat and cool our homes; the rest went to lights, heating the water, and powering appliances and electronics.

Figuring out how to make a house less of an energy hog can feel overwhelming. Sure, you can replace incandescent bulbs with LEDs, caulk your windows and doors, and install a smart thermostat like Nest. But once you start thinking about larger investments in systems like tankless water heaters, geothermal heat pumps and solar panels, the costs balloon. It’s hard to know where to put your money, and which investments might make the most sense for your home.

Homeowners may soon have to start thinking more seriously about reducing their footprint. In New York state, legislators passed a sweeping climate bill last month that will require the state to cut its emissions to 85% below 1990 levels by 2050 and offset what remains by 15%. To meet the new standards, homeowners will likely have to make big changes, like trading gas-fired furnaces for electric ones and adding solar panels to their rooftops.

To start to figure out how much of a polluter I am, I plugged my information into an Environmental Protection Agency carbon footprint calculator and discovered that my household of four with one car emits 33,110 pounds of carbon a year — about 30% less than the average household. If I made some modest improvements, like buying a new refrigerator, washing all my laundry with cold water and turning my thermostat down a few notches in the winter, I could shave off another 3,000 pounds a year. The suggestions seemed doable, but hardly heroic, and left me wondering what my emissions goal should actually be.


How green is green enough?

Casius Pealer, the director of Tulane University’s Master of Sustainable Real Estate Development program, said that the answer to that question varies depending on things like geography, the size and age of your house, and whether your energy was produced from cleaner sources.

“Energy efficiency is a bit like personal health,” Pealer told me. “You have to decide what is healthy enough for you, and then set a realistic plan to achieve that goal, and then maintain it over time.”

Pealer suggested we start by studying our homes. A high-efficiency HVAC system may eventually be a great investment, but it shouldn’t be your first. Your first step should be to figure out where your heated or cooled air is escaping from your house and then take steps to stop it from escaping. “Limit the waste and then figure out efficient ways to produce what you do need,” he said.

Start by actually reading your utility bill, and not just the total at the bottom. Pull up the last 12 months to get a better sense of how and when you use energy. Next, get an energy audit of your home, a process in which a technician pinpoints where a home is wasting energy and then suggests ways to reduce the waste.

Bringing water to and from your house uses energy too, so reduce water waste. You could, for example, install a smart monitor like Flo by Moen, which detects leaks and allows you to remotely shut off the water to your house from your smartphone.

Small changes can have a substantial impact

Consider Ann Jacobs and Brad Brunson. The couple was living in an 1897 Victorian house in Milwaukee that was so drafty in the winter they had to use space heaters in the living room to stay warm. “It was horribly cold,” Jacobs, a lawyer, said of the time in the early 2000s. And the heating bills were out of control. “They were just hundreds upon hundreds of dollars,” she said. “It was just beyond belief.”

Friends suggested they replace all their windows, an expensive project for a house with 16 windows on the front alone, many of them made with leaded glass, which provided character and matched the architectural style of the home. First they got an energy audit, with the auditor testing how air moved through the house and where it escaped.

They learned that the walls had no insulation and heat was escaping through the attic and basement. So they insulated the walls and attic, and replaced only the basement windows, a project that cost substantially less than what it would have cost to replace all the windows in the house. “All of a sudden we had a house we could live in,” Jacobs said. “People underestimate that little changes make a huge difference.”