Housing People Today, at a Fraction of the Cost.
Why Funders of New Construction Should Fund Home Sharing Too.

Many of the foundations and nonprofits that care most about housing put their money into new construction. They are right to. The country needs more homes than it is building, and nothing in this post argues for building one fewer. But a new affordable apartment takes years to open, and the people who need a place to live, or need help keeping the one they have, need it now. There is a second kind of housing supply that exists today, costs a small fraction as much to bring online, and almost nobody is funding.

What a new apartment costs, and how long it takes

Most affordable rental housing in the United States is financed with the Low-Income Housing Tax Credit. It works. It is also slow and expensive by design: land, permits, financing from several sources, construction, and lease-up. Two years or more from commitment to a family moving in is normal.

To make the cost legible, we worked through one apartment built on typical current tax credit terms. It is an illustrative example rather than a named project. That one apartment costs about $300,000 to develop. Counting the tax credits claimed over 30 years and the grants that go into it, the public subsidy behind it is about $281,000.

A good part of that is not construction. In the illustrative example, about $225,000 pays for labor and materials. About $141,000 of the public subsidy is a financial return to the investors and lenders who supplied the capital. That is not a flaw in the program; it is how the tax credit attracts private money at all. But it means a dollar committed to construction buys considerably less than a dollar of building.

The housing that is already built

There are about 35 million spare bedrooms in homes owned by older adults in this country. No land to buy, no permit, no construction loan. What turns a spare bedroom into housing is a homeowner willing to share it, a person who needs it, and the work that introduces them safely.

The need on the homeowner's side is just as real. Our new research, Staying Home, finds that about 13.5 million older homeowners, roughly four in ten, either cannot cover their basic costs or are barely covering them, and that financial pressure drives about 120,000 of their moves each year. About 3.1 million to 4.2 million of them could cover their basic costs and stay by renting out a room. A shared room houses the person who moves in and keeps the homeowner in the house. Construction does one of those. Home sharing does both.

What four months showed

In May 2026, HomeShare launched a new national model on its platform. Home providers and home seekers each pay a modest platform fee, and charitable gifts fund the nonprofit work around it.

Between late May and late September, 52 homeowners listed a room on the platform. Each one is a confirmed room, in an existing home, ready for someone to live in. Each one is a unit of housing that was not on offer four months earlier.

The pace has held at about 13 new rooms a month, from May through September.

A tax credit developer takes two years or more to deliver one new apartment. In a third of that time, home sharing added 52.

What one room costs to bring online

We hold home sharing to the same standard as construction: the cost to create one unit, before anyone has moved in. A developer is measured on apartments delivered, not on how fast they lease. So is this.

• Reaching the homeowner: about $769 per room. HomeShare's outreach to homeowners currently runs on about $10,000 a month in Google Ad Grants, divided by the pace of about 13 new rooms a month.
• An incentive to list the room: $1,500, the amount the City of Portland now offers a homeowner for a first room in its home sharing pilot.
• Total: about $2,269 per room brought online.

Against about $300,000 for one new apartment, that is less than one percent of the cost. Put another way, the $22.5 million that builds about 75 tax credit apartments could, on these figures, bring roughly 9,900 rooms into home sharing.

What we are not claiming

We want this comparison to survive a skeptical reader, so here is exactly what it is and is not.

• The 52 rooms are counted, not estimated. They come from the platform's own records. The cost figures are our estimates, built from those records and stated assumptions.
• The construction figures are illustrative. They follow typical current deal terms, not a named, audited project.
• A listed room is a unit, the same way a finished apartment is. Neither one is a household until someone moves in. How quickly our rooms are filled, and how long a typical match lasts, are what we will report next. Neither side of the comparison includes the cost of leasing or matching.
• Scale is untested. The $769 figure may rise as the easiest homeowners to reach sign up first. The 9,900 figure is a straight-line extrapolation from a small start.
• A shared room is not a substitute for a restricted apartment. It carries no 30-year affordability restriction and no rent set by a published table. That is why the argument is to fund both, not to choose.

Those are the questions a funder's investment would answer. Measuring matches, move-ins and how long arrangements last, consistently, is part of what we are asking you to pay for.

Why this cannot fund itself

If bringing a room online costs so little, why is it not already funded at scale? Because nobody earns a fee when an older homeowner opens a spare room. Construction comes with the machinery to pay for itself: tax credits, investor equity, permanent debt, developer fees. Those fees fund the people who assemble the deals and the advocacy that shapes housing policy. In home sharing, the rent goes straight from the person renting the room to the homeowner. That is exactly why it is efficient, and exactly why nobody is paying for the outreach, verification, screening and agreements that make it work.

That is the gap philanthropy is built to fill.

What we are asking for

We are asking funders who support new construction to support home sharing alongside it, as two parts of one strategy: build, preserve, convert and activate.

A gift to HomeShare Oregon pays for three things.

• Bringing homeowners forward. The outreach behind 52 rooms in four months, sustained and extended, reaching older homeowners in the years when the pressure is building rather than the week the house goes on the market.
• Making each match safe. Identity verification, background checks in both directions, introductions on how people actually live, and written agreements. The homeowner should not have to pay for the infrastructure of trust.
• Measuring what happens. Matches, move-ins and how long they last, so the next funder sees results rather than sign-ups.

Keep building. The rooms are already there, and they can be housing people this year.

Read next

Housing Capacity Parity is our policy framework for recognizing activated housing alongside new construction.

Staying Home has the figures for every state, including how many older homeowners could stay by sharing a room.

Build, Preserve, Convert. And Activate. is the longer argument for counting activated housing alongside new construction.

Sources

• Rooms listed and pace: HomeShare national platform records, 24 May to 24 September 2026.
• Cost of one new apartment, public subsidy and where it goes: HomeShare Oregon analysis, 2026. An illustrative example built to typical current 9 percent Low-Income Housing Tax Credit deal terms, not a named project. The subsidy figure counts the full face value of credits claimed over 30 years plus direct grants.
• Cost to bring one room online: HomeShare Oregon analysis, 2026. Outreach is about $10,000 a month in Google Ad Grants divided by about 13 new rooms a month; the incentive is the City of Portland pilot's $1,500 first-room grant, applied as an assumption. Excludes HomeShare's general operating budget and the cost of matching.
• The $22.5 million comparison: HomeShare Oregon analysis. A straight-line extrapolation of current cost and pace; it does not model whether either holds at larger scale.
• Spare bedrooms: HomeShare America, The Rooms Already Exist, American Community Survey 2023. It counts possible capacity inside occupied homes, not proof that a room sits empty.
• Older homeowners at risk, moves and "could stay": HomeShare Oregon, Staying Home, 2026, measured against the Elder Index. The moves figure is a central estimate within a range of about 61,000 to 207,000 a year.