ADUs for Adult Children: How NYC Families Are Keeping Generations Close

One of the most common — and the most meaningful — reasons people build ADUs in New York City isn't for rental income. It's for their kids.

Adult children are living at home longer than ever before. The reasons are obvious: sky-high rents, student loan debt, and the high cost of living in New York City. For a lot of young adults, moving out just isn't realistic right now. But living in your childhood bedroom as a 20-something isn't exactly ideal for the children or the parents.

That's where an ADU comes in.

Why an ADU Makes Sense for Adult Children

An ADU gives your adult child their own space — their own front door, their own kitchen, their own life — while still being close to family. It's not "living at home" in the traditional sense. It's living on the same property, but independently.

For parents, it's a way to help your kid without enabling dependency. For the adult child, it's a way to save money, build a foundation, and still have autonomy.

What Does the Setup Look Like?

Most families building ADUs for adult children go one of two routes:

• The kid lives in the ADU rent-free (or at a reduced rate) while they save money, pay off debt, or get their career off the ground. The understanding is usually that this is temporary — a few years, not forever.

• The kid pays market-rate or below-market rent, and the parents treat it like a rental property. This works especially well if the parents plan to eventually convert the ADU into a true rental unit once the kid moves out.

It's Not Just About Money

Can living in an ADU can save your kid thousands of dollars a year in rent? Sure. But for a lot of families, the bigger benefit is proximity. You get to see each other regularly without living on top of each other. Sunday dinners are easy. Babysitting future grandkids is easy. Helping each other out is easy.

And when your kid does eventually move out, you've got an income-generating asset sitting in your backyard.

What If They Never Leave?

That's a fair concern. But here's the thing: an ADU done right doesn't feel like "home" in the way a childhood bedroom does. It feels like a real apartment. And real apartments are easier to leave when the time comes.

Plus, even if they do stay long-term, you've created a setup where everyone has space and independence. That's a win-win.

The Tax and Legal Side

If your adult child is living in the ADU rent-free or below market rate, there may be gift tax implications depending on how much rent you're forgiving. It's worth talking to an accountant about how to structure the arrangement. Most families find that a nominal rent payment keeps things simple.

Thinking About Building for Your Kid?

A free assessment will show you what's possible on your property — and how much it will cost to make it happen.