FAIRFIELD — Melanie Marks has been a tennis instructor. And worked for an insurance company. And been the office manager for a day care center.

“I’ve done a million things,” Marks, a town resident for 27 years, said. “I just keep re-inventing myself.”

But since 2009, Marks has kept her focus on the past, with the creation of Connecticut House Histories, using expertise she has honed over the years to trace the lineage of old homes.

“I studied early childhood education,” Marks said, laughing, but added she has always loved history. “My parents were antique collectors and dealers, so I’ve always been around that.”

Q: How did Connecticut House Histories get started?

A: I bought an antique house on Bronson Road. I was curious about the owners. I had never really done the history of a house.

A friend, who was then the chairman of the Westport Historic District, had four historic houses they were trying to get listed. He allowed me to do the history. I did it for free, for the experience. Then, it just took off. Somebody told me in order to compete with the others doing this I needed to look more professional. So, I started the website and that’s when I created my company.

I don’t advertise, it’s all word of mouth. We did a project for the Connecticut Trust for Historic Preservation, and the executive director called us a ‘brand.’ That was the biggest compliment I ever received.

Q: Why investigate the history of properties?

A: It’s a combination of an interest in the owners of the house, and making sure what you were told was correct. You can’t do this kind of research without being a genealogist.

Q: How do you start your research? What does the homeowner get?

A: The first thing I do is a title search. I don’t use anyone else’s work. Once I know that, I can go from there.

The owners get a complete history: who built it, the approximate build date, and they know who all lived in it. They get all of the supporting documents in a humongous binder. t’s a book, really.

I don’t have employees, but I surround myself with some very incredibly talented consultants who work with me, and that’s how I can do what I do.

Q: What is the oldest house you’ve researched? The most interesting?

A: It’s probably going to be the one I just bought. The plaque says 1700, but I’ve been told it’s probably more like 1690. But that’s going to have to wait.

So, it would have to be the Hatch House in Kent, built in 1741. That was done for the South Kent School, who was gifted the property.

The most interesting would be the Lyman House, for the Connecticut Trust, in Durham. The builder of the house was Thomas Lyman, who got booted out of the church because he got a woman pregnant in 1790-something. That was a surprise. He also got in trouble for working on the Sabbath. That was a big no no. He was just a bad boy.

Q: Is your work just limited to Connecticut?

A: I just don’t do this here. I have clients all over the country, and I have clients in other countries. I just finished the Garvin-Garvey House in Bluffton, S.C.

I received a state historic preservation award from the governor of South Carolina for the work I did on this house. That was probably one of the more exciting things.

I’m everywhere, but that’s what’s fun about it. I never know what project is going to come down the pike. It’s like living a live history book. There’s just so many stories. You can’t make this stuff up.