Estimated spare bedrooms
A few examples
Search a place to see how much spare-bedroom capacity it may already have.
Spare Room Estimator
Solving America's housing shortage requires more than building homes—it also requires making better use of the bedrooms we already have.
I estimate how much co-living capacity may already exist inside occupied homes by comparing the bedrooms already there with the bedrooms people need.
According to this tool, the United States has over 108 million estimated spare bedrooms in occupied homes.
Why it matters
The idea behind it
America can increase housing capacity not only by building more homes, but also by making better use of spare bedrooms already inside occupied homes.
In this estimate, a spare bedroom means potential housing capacity inside an occupied home. It does not mean the room is move-in ready today.
FAQ
Common Questions
FAQ
Common Questions
Does this count vacant homes or vacation homes?
No. This estimate focuses on occupied homes, not vacant, seasonal, or second homes. For rough context only, a separate back-of-the-envelope estimate suggests about 13 million spare rooms in vacation homes and about 25 million in currently vacant homes. That is not part of the core estimate.
Does a “spare bedroom” mean the room is empty?
Not necessarily. In this estimate, a spare bedroom means potential capacity, not proof that a room is sitting unused. Some of these rooms are offices, nurseries, guest rooms, hobby rooms, or storage spaces.
Why do some regions have negative spare bedrooms?
A negative result means I estimate more bedrooms are needed than are available in occupied homes under the site’s assumptions. That can happen in places with many couples, children, or other adults sharing homes, or with many smaller units. It does not mean the place has literally “negative bedrooms.” It means the model sees a shortfall.
What about studio apartments?
Studio apartments count as occupied homes if someone lives in them, but they usually count as zero-bedroom units. The ACS counts about 445,280 occupied zero-bedroom units nationwide, so they are real housing but not enough by themselves to drive the overall result. They do not add to the bedroom total the estimator measures.
How was this estimator built?
I built it over the past six months with help from OpenAI's Codex program, which I used as a coding partner while I shaped the assumptions, checked the Census data, and refined the wording. Codex helped speed things up, but the judgment calls were mine.
Is this anti-YIMBY or anti-construction?
Not at all. I agree with a lot of the YIMBY case for building more housing, and in many places we clearly need more construction. Yes In My Spare Room is not meant to replace that argument. It is meant to widen it by asking whether the housing conversation should also pay more attention to the bedrooms that already exist inside occupied homes.
Is this legal?
It depends. Co-living, boarding, and other shared housing arrangements used to be very common in American life, but many places now restrict them through occupancy limits, zoning rules, leases, or HOA policies. If your area makes shared housing unnecessarily difficult, a constructive response is to encourage local and state leaders to make these arrangements easier and more workable.
How can a community increase its spare room capacity?
Some of it comes from household choices, and some of it comes from the built environment. Families may decide that siblings can share a room. Homeowners may convert underused attics, basements, offices, or dens into legal bedrooms. Builders and renovators can design homes with future boarders, relatives, or roommates in mind. And local governments can help by allowing more flexible shared housing arrangements.
How exact are these numbers?
These are estimates, not a literal room-by-room census. The tool uses recent Census survey data on occupied bedrooms, household structure, and children, then applies transparent assumptions to produce an estimate. The goal is to keep it grounded and useful without pretending to know more than the data can really tell us.
How has spare-bedroom capacity changed over time?
How do I host people in my spare room?
You can of course invite a friend or family member to live in your spare room. Alternatively, you may consider renting it to well-vetted strangers through a room rental platform like PadSplit.
How do I find a spare room to stay in?
Consider reaching out to members of your network to ask if they know a friend or family member who might have a spare room that could be made available. Alternatively, you can look into room rental platforms like PadSplit.
County Map
Where spare rooms are more or less common
This map shows spare bedrooms per 10 occupied households. Click a county for the full estimate; hover to browse quickly.
Legend
Darker colors mean more estimated spare-bedroom capacity per 10 occupied households.
Loading county map...
Methodology and sources
How the estimate is built
- The estimate uses recent American Community Survey data from the U.S. Census Bureau.
- It combines occupied bedroom counts, household size, couple-household counts, and the number of people under 18.
- The model then estimates how many bedrooms are already spoken for under these assumptions and compares that to occupied bedroom supply.
Technical table details
- Occupied bedrooms: ACS table
B25042 - Household size: ACS table
B11016 - Total, married-couple, and cohabiting-couple households: ACS profile table
DP02 - People under 18: ACS profile table
DP05
When the PUMA follow-up appears
- The PUMA follow-up uses ACS 2024 1-year PUMS microdata at the PUMA level.
- PUMAs are broader regions than ZIP codes, cities, or many counties, so this section is more regional and inferential than the main estimate.
- For some counties and states, the site uses precomputed countywide or statewide aggregates built from one or more PUMAs.
- For many ZIP searches, the site now pairs the ZIP with a best-fit broader county/PUMA pattern rather than a ZIP-specific microdata profile.
Reproducibility appendix
- Start with ACS 2024 5-year Census API tables for bedrooms, household size, household type, and age.
- Estimate required bedrooms as: married or cohabiting couples + other adults + children under 18, with one bedroom assigned to each child in the public version.
- Estimate spare bedrooms as occupied bedrooms minus required bedrooms. The uncertainty bands come from the Census margins of error.
- For the illustrative snapshot, use the same estimated totals but turn them into a stylized five-home scene rather than a literal household allocation.
- For ZIPs, places, counties, and states, use the same broad matching and fallback rules that the site uses in code rather than assuming every geography maps cleanly to a single Census unit.
- The PUMA follow-up is a separate, broader layer built from ACS 2024 1-year PUMS microdata and should be reproduced as a companion model rather than merged into the core estimator.
Source data used for this estimate
Keep Going
If this argument resonates, take the next step.
Yes In My Spare Room is meant to be both a measurement exercise and an invitation: to see spare rooms as real housing possibility, to consider shared housing where it makes sense, and to widen the conversation beyond construction alone.
About Andrew
Who built this
Andrew Berg graduated from Franklin & Marshall College in 2012 with a double major in history and government.
After graduating, he taught middle school science in Baltimore through Teach for America while earning a Master of Education from Johns Hopkins University.
He now serves as Area Director for InterVarsity Christian Fellowship in central Pennsylvania, supervising staff, volunteers, and student leaders at fifteen colleges.
Andrew has practiced co-living in a variety of forms. Whether through short-term visits or long-term guests, he has experienced the highs and lows of shared housing and still loves it.
He also wrote about the idea in Plough: Yes In My Spare Room.
For more on the argument behind Yes In My Spare Room, or on Andrew's experience with shared housing, visit the Yes In My Spare Room Substack blog.
Questions, feedback, or media inquiries? Reach Andrew through the Yes In My Spare Room Substack blog or on LinkedIn.