Claudia Bohnert moved to Dutton Avenue in Catonsville last fall only after researching the town and her new address's proximity to shops and amenities.

She knew that once she settled into her new house, she didn't want to drive much.

"That's really an important feature for people who are trying to be green," she said.

The recently retired pharmacologist said she became aware of, and devoted to, the idea of living a green life after hearing about the concept a few years ago.

Now 60, she hopes her new house in Catonsville -- from which she said she can easily walk to the library, the senior center and many businesses -- will help facilitate her green-minded lifestyle in retirement.

And to make sure, she hired the Catonsville-based architectural firm of Brennan and Company as green consultants.

She said she saw a listing for Brennan and Company in an issue of Smart HomeOwner magazine during her research.

When she saw the firm's Frederick Road address, she realized they were right down the road.

Since that realization, Rob Brennan, principal of Brennan and Company Architects and owner of Alterego, a Frederick Road showroom of sustainable, green building supplies, has been central to the creation of Bohnert's green team as its first member, Bohnert said.

She has also hired a landscaping crew to maximize the green capabilities of her yard and a heating company to rip out her old oil heating system and replace it with a geothermal system.

Bohnert said she called Brennan before she'd even spoken with a real estate agent and was still living in an apartment in Oella Mills, biding her time before finding a house that fitted her needs.

With the architectural know-how to implement green changes to older houses -- the one Bohnert settled on in November dates to 1940 -- and the local business presence to supply the materials for such work, Brennan was the perfect partner in starting a search for a green home and future, Bohnert said.

"He can evaluate each potential option for making something green," she said.

He could also bring in others to help bring those changes about.

Brennan suggested Bohnert start her search for a new home by contacting Kirby Spencer, a real estate agent with Coldwell Banker Residential Brokerage on Frederick Road and a longtime resident of the same neighborhood in which she would eventually help Bohnert find a home.

Once Spencer located a home that fit Bohnert's specifications, Bohnert had Brennan evaluate it to make sure it could be renovated in a way that made it green -- or at least greener.

Bohnert is now renovating the home so that it uses less energy.

Windows are being replaced to put less strain on the heating and cooling system.

Faucets are being replaced with "low flow" taps that cut down on the amount of water she will use.

And she hired Love's Heating & Air, Inc., a company based in Severn and another Brennan contact, to replace her home's heating system.

The electrically powered system pumps water through tubing that, in the case of Bohnert's home, goes 300 feet under her front yard. The company had to drill through granite to create the path for the tubing.

The temperature of the earth at that depth, regardless of the weather at the surface, remains at a relatively constant 58 or 59 degrees year around.

According to John Love, the company's president, the geothermal heat pump is an environmentally friendly way to control the temperature inside a home.

The system draws heat out of the depths of the earth in the winter and takes heat out of the home and releases it into the ground in the summer.

"We're actually pulling energy from the ground," Love said.

Because the earth is so massive, it can absorb large amounts of warmth, or give it up.

And because water can hold far more heat than air, the water system is efficient in harnessing the earth's heat and transporting it to the house.

Though this is his first geothermal installation in Catonsville, Love said his company has installed thousands of geothermal systems throughout Maryland, and the demand for them has been increasing for years.

Carri Beer-Harlan, an associate architect with Brennan and Company working with Bohnert, said she has seen a similar increase in such interest.

She said more people are coming to the company educated on what it takes to be green.

Still, she said, "There's a lot out there and it's hard for any one person, when it's not their job, to figure it all out."

That's where the architecture firm's expertise comes in handy.

"We always ask, 'How green are you?'" Brennan said. "Everybody is a different shade of green, and everybody has a different budget."

Love said the geothermal system, while an investment up front, will end up saving Bohnert money in the long run.

It will also make her eligible for federal and state grants.

Replacing windows and making sure a house is tightly sealed may save money over time.

But as Bohnert put it, it takes a dedication to the idea of being green to really put in the time and effort to learn about available options and go through with them.

It isn't easy or inexpensive, she said, but for her, it's about the future.