This year, a small county in Oregon opened a new affordable apartment building: 50 homes for residents 55 and older. It was a good project, and the county needs more like it. It cost about $22.6 million, or about $452,000 for each unit, and it took about four years to go from funding to opening day. We asked a simple question. What would the same money do if it were spent on rooms that are already built?
The arithmetic
We recently priced a home sharing program for that same county. A year costs about $15,000, for up to 50 homeowners sharing a room:
- about $7,000 for the matching platform, verification and screening, and support for both people in each match;
- about $5,000 for digital and print outreach, so homeowners hear about it from people they trust;
- about $3,000 for a stipended local worker.
Run that program for 30 years and it costs about $450,000. That is about what it cost to build one unit.
One new unit: about $452,000. About four years from funding to opening. Over 30 years, it houses about 3 to 5 people.
Thirty years of home sharing: about $450,000. Up to two years to activate 50 rooms. Over 30 years, those rooms could house about 150 to 250 people, while 50 homeowners stay in their own homes at any one time.
Why the difference is so large
The difference is not that construction is wasteful. It is that construction pays for everything: land, materials, labor, financing, and decades of upkeep. Home sharing pays for none of it, because the room already exists. It is already built, already on the tax rolls, and already connected to roads and water. The money goes to the work of bringing two people together safely and keeping the arrangement steady.
The people counts come from how long people usually stay. HUD's research on assisted housing finds households stay about six years on average, and older households about nine. Applied to one unit over 30 years, that is about three to five people, since these are one-bedroom and studio homes. Applied the same way to 50 shared rooms, it is 150 to 250 people.
Speed matters too
The new building took about four years from the funding award to opening. Over those same four years, a home sharing program that reached 50 homeowners in its first year could house about 70 to 80 people in shared rooms, allowing for normal turnover. Add the 50 homeowners who stay in their homes, and more than 120 county residents would be helped for about $60,000, while the building was still going up.
In unit terms, 50 rooms activated over up to two years for about $30,000 is about $600 per affordable unit, or about $300 per person helped.
It is prevention, too
Every one of those 50 homes belongs to someone who wants to stay in it. In that county, about one homeowner in four spends 30 percent or more of their income on housing. For an older homeowner on a fixed income, the rent from one room can be what keeps the house. A homeowner who stays is a household that never needs a new unit at all.
Our research shows how common that pressure is: about 13.5 million older homeowners across the country either cannot cover their basic costs or are barely covering them. Staying Home has the figures for every state.
What this comparison does not say
A fair comparison says what it leaves out.
- A room is not an apartment. It has no rent held down by a 30-year covenant, and it is not the right home for everyone. Some people need a place of their own.
- The home sharing figures hold today's price flat for 30 years, with no inflation, and they assume the program reaches 50 active homeowners and keeps them. That takes steady outreach and good matches.
- The costs leave out the county's own staff time and any extras, such as homeowner incentives.
- Home sharing does not replace building. It works alongside it, and it can house people this year, including while they wait for new units to open.
Communities need to build, preserve, convert, and activate. Activation is the part that has almost never been funded.
Where philanthropy fits
A county or a housing task force can fund the program itself. Philanthropy can do the things that make it work faster and reach further:
- Fund the first year, so a county can see results before it commits its own budget.
- Cover participants' fees, such as background checks and the written agreement, so cost is never the reason a homeowner says no.
- Fund homeowner incentives that help a homeowner take the first step.
- Train the local people who refer, at the Area Agency on Aging, the library, the congregation, and the employer, because homeowners join when someone they trust tells them about it.
- Fund the research that gives every county its own numbers, so the next task force does not have to start from scratch.
One new unit is a home for a few people over a generation. For about the same money, the rooms already standing in a county can be a home for hundreds.
Read next
Housing People Today, at a Fraction of the Cost. The same comparison at the national level, from October.
How to Start a Home Sharing Program. The method behind the county plan, step by step.
Sources
- New construction: public reporting on a 50-unit affordable building for residents 55 and older in a small Oregon county, with one-bedroom and studio homes, budgeted at about $22.6 million at its state funding award and opened in 2026.
- Home sharing program cost: HomeShare's county program budget, October 2026, for up to 50 home providers. Thirty-year totals hold the price flat, with no inflation.
- Length of stay: K. McClure, Length of Stay in Assisted Housing, HUD Office of Policy Development and Research, October 2017 (about 6 years on average across programs; about 9 for older households), applied the same way to shared rooms.
- Cost-burdened homeowners: U.S. Census Bureau, American Community Survey 2020 to 2024 5-year estimates, table B25091.
- Older homeowners under financial pressure: HomeShare Oregon, Staying Home, 2026.