Brit transplant Elizabeth Noble imagines what goes on behind the closed doors of an Upper East Side apartment building in The Girl Next Door.

The book features a character very much like yourself: a British ex-pat living in New York City who followed her husband's relocation to a new job. She often sounds very homesick. You, too?

I sometimes refer to the book as my little piece of therapy. I wrote it the second year I was here. It was my toughest year, and I just wanted to go home. Eve shares a lot of my feelings of not belonging. New York is a tough gig. Nobody has the time to explain to you that you have to go at the speed the city goes. And if not, you get steamrollered.

The women in your novel draw their real strength from their female friends. Is this an important point in your own life, too?

That's a part of why it was hard for me to acclimatize here. My best friends were at home, as is my mother, whom I'm close with. Particularly in your child-rearing years, your women friends form the basis of your support network. The sisterhood is crucial, and yes, it was hard to rebuild.

For all her feelings about moving to a new country, Eve doesn't seem to regret the loss of her job.

For Eve, within her marriage, it was always that she had the job and Ed had the career. That's how it is for some marriages and for some women; they're able to view what they do as one stage, then there will be another.

The other couples in the novel, Kimberly and Jason, and David and Rachel, while successful, don't have it easy. Do you think two-career couples have it harder?

I think the danger with running a life that is so ostensibly successful is, you have to spend so much time maintaining the infrastructure. High-profile, high-stress lives are always in trouble if you let the fundamentals go. Like Kim and Jason, they let the need to have a baby sweep their own relationship aside. When my babies were small, my husband was so far down the list—it's the norm.

Using the lives of people living in the same building is a pretty tried-and-true setup for a novel. What drew you to it?

One of the things I think is so fascinating is that New York has an incredible intimacy and a great sense of privacy. In an apartment building, if your intention is to write lots of different stories, it's manna from heaven.