What a Multigenerational Home Actually Needs

A multigenerational home is one where more than one adult generation lives together: parents and their adult children, often with grandchildren. Nearly 60 million Americans live this way, four times as many as in 1971, according to Pew Research Center.

Here's what the listings won't tell you: most homes sold as “multigenerational” are a regular house with a spare bedroom and an optimistic description. A real multigenerational home is built around one principle, privacy for each generation, and shared space for everyone. Every feature that matters serves that principle. Everything else is decoration.

We know because we went shopping for one. Our founders spent months walking houses around Seattle with their own family, looking for a home that could hold everyone. Plenty of listings used the word. Almost none passed the checklist below, and the one that came closest still needed serious work to actually live the way the listing promised. (That search is our own family’s story.)

The checklist: what actually matters

We have spent a decade helping families co-own homes together, we publish the annual CoBuy Co-ownership Index™ on how many Americans buy together, and we score homes on how well they work for shared ownership. This list comes from scoring real properties and from walking those houses ourselves, not from theory. In rough order of importance:

A second entrance. The single biggest difference between living together and living on top of each other. If one generation can come and go without walking through the other's living space, everything else gets easier. If not, everyone is a guest in someone else's house.

A second kitchen, with a real cooking source. A kitchenette with a microwave is a hotel room. A kitchen with a range means a generation can actually run its own life: its own groceries, its own meals, its own schedule. This is the feature that separates a home that genuinely works for both from a house with a big bonus room.

A bedroom and full bath on the entry level. Stairs decide who can live in a home for the next twenty years. An entry-level suite keeps every option open, for grandparents now or for you later. Wider doorways and a walk-in shower cost little during a rebuild and keep the home working for decades. This is planning, not pessimism.

Living space that closes off. Each generation needs somewhere to be alone: a den, a sitting room, a wing with a door. Bedrooms aren't enough. If the only shared-free zone is a bedroom, people start living in their bedrooms.

Doors that lock between zones. It sounds cold. It's the opposite. A lockable door between living areas is what lets everyone relax, because privacy that depends on politeness isn't privacy.

Sound separation. Different generations run on different clocks. A laundry room, a TV wall, or a bedroom stacked over someone else's is a daily argument waiting to happen.

Parking for everyone. More than one generation means three or four cars. A driveway that fits one is a small thing that grinds every single day.

A permitted, legal second unit, if there's one. If part of the home is a separate unit, whether it's legal changes everything: financing, insurance, resale, and whether you can rent it out later. Unpermitted work can undo most of the value the space would otherwise add.

Does an in-law suite add value?

Usually, when it's permitted and built properly. (An in-law suite, a mother-in-law suite, and a mother-in-law apartment all mean the same thing: a self-contained living area inside or attached to the main home.) A self-contained suite or a legal second unit widens the pool of future buyers and can produce rental income when your needs change. Unpermitted work does the opposite: it can complicate the loan, spook insurers, and slow a sale.

But value is the second question. The first is whether the suite actually works for a person to live in long-term. One bedroom and a bathroom off the garage is storage for a relative, not a home. The features above are what make the difference.

The four levels of separation

Not every family wants the same distance. It helps to think in four setups:

1. Shared home, private suites. One kitchen, shared living space, each generation with its own bedroom and bath. Works for close families and smaller budgets. The least privacy.

2. Separate wings. One house, two living areas, a second kitchen, a wing that closes off. Everyone runs their own life under one roof.

3. Main house plus a second home. A separate smaller home on the same property, fully independent, shared land. Real independence, shared daily distance.

4. Two homes, one property. Fully separate structures. As much distance as a family can have while still sharing a fence line and a future.

The right answer is whichever one your family would actually enjoy living in. The problem is what comes next: homes at levels 2 through 4 barely exist on the open market.

Is a multigenerational home right for your family?

It's right when two things are true: the arrangement makes financial sense (one property instead of two usually does), and everyone gets real privacy by design rather than by politeness. If the two generations are you and your parents, the money and the ownership have their own answers: here is how buying a home with your parents works. It goes wrong in one predictable way: a family moves into a regular house and hopes goodwill will substitute for a floor plan. Goodwill runs out around the second shared-kitchen conflict. If the home passes the checklist above, the living part tends to take care of itself. If it doesn't, no amount of family harmony fixes the architecture.

Why almost no homes pass the checklist

Houses get designed for one family. One kitchen, one primary suite, one front door. Builders are starting to adapt, and some new communities now include homes with space for a second generation. But the existing homes for sale in any given month? The ones that genuinely pass the checklist are rare, and the ones that come close usually need serious work: a second kitchen, a new entrance, a reworked layout. It's exactly why we started scoring homes on how well they support shared ownership: most of them flunk.

Which leads to the conclusion most families reach eventually: you're unlikely to find this home. You're far more likely to build it. Buy a property with something to work with, then rebuild it so each generation has its own space and everyone shares a home.

There's a name for that. It's a compound, and with the rules changing in states like Washington, where many lots can now add a second home, it's more achievable than it sounds.

Frequently asked questions

What makes a home good for more than one generation?

Privacy for each generation and shared space for everyone. In practice that means a second entrance, a second kitchen with a real cooking source, an entry-level bedroom and bath, living space that closes off, and sound separation. A spare bedroom isn't enough.

What is the difference between a multigenerational home and a house with an in-law suite?

An in-law suite is usually one bedroom and a bathroom attached to the main house. A real multigenerational home gives each generation a genuinely separate living area, often with its own entrance and kitchen, so nobody is a guest in someone else's home.

Does a separate living space add value?

Usually, when it's permitted and built properly. A legal second unit widens the pool of future buyers and can produce rental income. Unpermitted work does the opposite: it can complicate financing and slow a sale. Permits matter more than finishes here.

Can you convert a regular house into a multigenerational home?

Often, yes, if it has good bones: a layout that can be split, somewhere to put a second kitchen and its plumbing, and a wall that can become an entrance. Permits usually decide the timeline more than the finishes do. In many places a second home can now be added to the same lot.

How much does it cost to make a home work for more than one generation?

It depends on what you start with. Turning a standard house into a genuine multigenerational home usually means a second kitchen, a separate entrance, and a reworked layout, which in the Seattle area often runs into the hundreds of thousands. Buying a property with more to work with, or land you can build on, is often the better path.

What is a compound?

One property set up so more than one generation can live there with real privacy: separate living areas with their own entrances, often a second kitchen, and shared space everyone uses.