Build your together home.
A home you all share, with private space for each generation. We help you find the property, structure the purchase, and build it to fit.
A founder reads every one.

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10 years
In business
3,500+
Co-buyers and co-owners served
$63M+
In transactions facilitated
200+
CoBuy-certified™ Pros
The house you need isn't listed.
You've seen the listings. One kitchen. One primary suite. One front door. Built for one family.
So you compromise.
Buy two places
Two of everything, and you give up the whole point.
Squeeze in together
Everyone on top of each other by month two.
Put someone out back
Alone in a small unit, without the run of the house.
“Before learning about CoBuy, my mother, husband and I went to see a lawyer to learn about the legal logistics of purchasing a house together. We met with him for just shy of an hour, and honestly, we left his office feeling more confused and more discouraged than when we went in.”
So build it instead.
A compound is one property where more than one generation can live together and apart at the same time.
Separate entrances. A second kitchen. A wing that closes off, or a second home at the back of the lot. Shared space where you want it, private space where you need it.
Four ways to live together.
You decide how close is close enough.
One house, shared day to day. One kitchen and one living room, with a private bedroom and bath for each of you. The closest setup, and the smallest project. Some families start here and add a second kitchen later.
Most families land somewhere between these. Yours will be its own thing, and that’s what the call is for.
- Shared by everyone
- One generation's own space
- The other generation's own space
Three ways to get a home that fits.
Which one you take depends on what you are starting with.
Find it
Buy one that already works
They exist, they are rare, and they go fast. We know the features that decide it and how to spot them in a listing.
What we look for
- A second entrance that does not cross anyone else's space
- A real second kitchen, not a kitchenette
- A bedroom and full bath on the entry level
- Living space that closes off, not just bedrooms
- Parking for everyone, and a permitted second unit if there is one
Renovate it
Buy good bones, then rework it
A second kitchen, a separate entrance, a wing that closes off, built by a CoBuy-certified™ Home Builder.
What this usually takes
- A layout that can be split without gutting the whole house
- Somewhere to put a second kitchen and its plumbing
- A wall that can become an entrance
- Permits, which decide the timeline more than the finishes do
Build it
Start from land
Bare land, or a house worth replacing. Drawn around how your family actually lives, then built by a CoBuy-certified™ Home Builder.
What you get to decide
- Where every entrance goes
- How many kitchens, and where
- Which rooms are shared and which are not
- Whether the second home is attached or its own building
We run all of it.
The hard part starts after closing. Your agent has been paid. Your lender has been paid. And you're standing in a house that doesn't fit yet.
We're with you the whole way.
Align first.
Who's in. Who lives where. Who pays what. What happens when plans change. Settled before anyone writes an offer.
Qualify together.
What you can do together, across generations of income and equity, including using both incomes to qualify.
Secure the right property.
Not just any listing. One that can hold more than one generation, or land worth building on.
Structure your ownership.
Who owns what share, in writing, before closing. Who put in what, tracked from day one, so the money never gets fuzzy.
Make it fit.
Two kitchens. Separate entrances. A wing that closes off. Renovated or rebuilt by a CoBuy-certified™ Home Builder.
Make it hold.
Someone wants out. Someone passes. Plans change. Decided up front, so it holds.
What a purpose-built multi-generational home looks like.
Snoqualmie, Washington. Built by Hughes Building Company. It's our co-founder's home, purpose-built for multi-generational co-ownership.
This is what separate-but-together looks like. The second living quarters, labelled ALQ on the drawing, has its own everything: bedroom, bathroom, kitchen, laundry, and a private patio entrance. One door connects it to the rest of the house, and it locks from either side.

Could your family's home work like this?
Tell us what you're working with. A founder reads every one and replies within two business days, fit or not.
Every professional you need, already certified.
Buying and building together takes a lot of professionals, and most have never done it. We certify the ones who have, hand-picked on track record and on how well they work with more than one client in the room.
- Real estate agents
- Lenders
- Title and escrow
- Attorneys
- CPAs
- Insurance
- Home buildersNew
Home builders is the newest discipline, and it's what makes this program possible.
See the CoBuy-certified™ Pro network →

CoBuy-certified™ Home Builder
Brian Hughes, Hughes Building Company
Forty years of custom residential construction in the Puget Sound area, including homes built for more than one generation on a single property.
A CoBuy-certified™ Home Builder is a licensed local builder we've vetted, with a track record of building homes that work for more than one generation: separate entrances, second kitchens, and permitted second units.
“Our questions were around how is this going to work? What will it actually look like? And is there any liability? Having that step by step process was great. A big thing for us was making sure that everybody felt secure in their investment. Having a neutral third party was essential for us.”
Who this is for.
- More than one generation, buying one property. Parents and adult kids, most often. Sometimes three generations, or a couple and one close family member.
- Greater Seattle. King and Snohomish counties, where our building partner works.
- A real build or rebuild in mind. Not a small job.
- Hoping to move within the next year or so.
Not a fit
- A backyard unit on its own
- A kitchen or bath remodel
- Buying on your own
We'll say so early.
Outside Greater Seattle? Email compound@cobuy.io and we'll tell you when we reach your area.
How to start your compound.
Start with what you know
Who's buying with you, roughly where, roughly what. No plan required, that's our job.
You hear back in two business days
Whether it can work, what it would take, and roughly what it costs.
If it fits, we all talk
You, us, and whoever needs to be in it. Not a salesperson.
Plan your multi-generational home in Greater Seattle.
Tell us what you're working with. A founder reads every one and replies within two business days, fit or not.
Takes about 2 minutes.
We take a few projects at a time, in the order they come in.
“Easy, frustration free, and educational. Working with CoBuy took the confusion and pain out of the buying process. The bonus was that we learned so much about home buying and all of the issues and concerns that might occur.”
More on buying a home together.
The three questions families ask first.
Score a home
CoBuy Suitable Homes™
How we score a home, 0 to 100, on how well it works for shared ownership.
Guide
Buying a house with family members
Our own family's story, and the questions we wish we'd asked.

Guide
JTWROS vs tenants in common
How co-buyers hold title, and why the choice matters more than people think.
Common questions about multi-generational homes.
What is a compound?
One property set up so more than one generation of a family can live there with real privacy. In practice that means separate living areas with their own entrances, often a second kitchen, and shared space everyone uses. Some are a single house divided into wings. Others are a main house plus a second home on the same lot.
What is a multi-generational home?
A home where two or more adult generations live together, usually parents and their adult children, sometimes with grandchildren. Nearly 60 million Americans live this way, four times as many as in 1971. The versions that last give each generation its own private space rather than just a spare bedroom.
How is a compound different from a house with an in-law suite?
An in-law suite, sometimes called a mother-in-law suite, is usually one bedroom and a bathroom attached to the main house. A compound gives each generation a genuinely separate living area, often with its own kitchen and entrance, so nobody's a guest in someone else's home.
Can a parent and an adult child buy a house together?
Yes. Both can be on the title, and lenders will look at combined income and assets. Families often do it because together they can buy a property neither could buy alone. What matters most is deciding in advance who owns what share, who pays for what, and what happens if someone wants out.
Does a separate living space add value?
Usually, when it is permitted and built properly. A legal second unit or a self-contained suite 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.
What 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 multi-generational 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 does CoBuy charge?
Every project is different, so we scope and price it after we understand what you are working with. That is one of the things the first call is for. We'll never quote you a number before we know enough to stand behind it.
Who owns what?
You decide, and you put it in writing before closing. Families buying together commonly hold title as tenants in common, which lets each party own a defined share instead of an automatic equal split. Shares can reflect what each side actually contributed, and it's worth recording contributions separately from ownership percentages.
What happens if one of us wants out?
You plan for it up front. A written agreement sets out how someone can be bought out, how the property gets valued, who has the first right to buy, and how much notice is required. Families who settle this before buying avoid ending up where selling the whole property is the only option left.
Do you only work in Greater Seattle?
The build side of this program is live in Greater Seattle first, because that's where our building partner works. We're expanding to other metros, so email compound@cobuy.io and we'll let you know when we reach your area. Everything else we do, helping families structure, finance, and govern owning a home together, we have done nationwide for a decade.
This page is general information, not legal, financial, or tax advice. For your own situation, talk to a qualified attorney, CPA, or financial adviser.



