For all the focus on sustainability around these parts, experts say the one area that could use some work is Oak Park's aging housing stock.
In Oak Park, there are roughly 7,600 housing units, and officials say the majority were built between 1900 and 1939. Those old bones present a series of challenges for homeowners looking for modern energy efficiencies and cheaper energy bills.
But where local homeowners may see frustration, Bonnie Marx sees as an opportunity to expand her family's business.
"Most people are devastated that [their money] is being wasted," she said. "It can be fixed."
Called Green Energy Improvements, Marx's is a full-service business that walks homeowners through an initial audit all the way through home repairs. It's now headquartered in the same Lombard Avenue two-flat that houses Seven Generations Ahead and Beyond Properties Realty.
Naturally, Marx got to work right away on the space, which resulted in a "Energy Star Silver Certificate" designation, among the first in the state. More homes are in the works, and Marx's goal is get at least 100 Illinois homes to the same level of certification.
According to the company's estimates, anywhere from 25 to 40 percent of a home's electric and gas bills are wasted on heating and cooling the air that ends up escaping through leaky cracks and crevices. At the Oak Park offices, Marx estimates that owners Gary and Erica Cuneen will save an estimated $2,408 each year on their utility bills and reduce energy consumption by 35 percent.
Typically, Marx said, the problem areas are where a home's foundation meets the first floor walls, and where the top floor's walls meet the attic. For $99, the company performs a "blower door test," a process that calculate the amount of air leakage in a home.
From there, the company will offer a roadmap toward solutions and provide estimates. Some services will be pricier than others, but Marx said the services will pay for themselves in the form of dramatically lower utility bills. And financing is available through a partnership with GreenChoice bank.
But there's also the comfort factor.
"If you have the financing, it's a quick return on your investment," she said. "Plus, you'll be comfortable forever."