On a rainy night in January, the National Association of Realtors published an article that should have alarmed every hopeful homeowner, empty-nester, and business entrepreneur in Eugene.

Seattle — where the median home value recently tipped past $620,000 — was named the most-constrained, least accessible housing market in the country.

But who was second?

Eugene.

On April 11, renowned architect and urbanist Daniel Parolek spoke at two local events about “missing middle housing,” a term he coined. “The key to missing middle housing is that it never gets much larger than a house,” Parolek explained. “Missing middle is about smaller, well-designed units in walkable neighborhoods.”

This remarkable range of housing designs — including duplexes, fourplexes, courtyard apartments, bungalow courts, row houses and live/work units — fills in the gap between typical single-family homes and mid-rise buildings.

But in many communities, including ours, these once-common missing middle housing types are now rare for a simple reason: we’ve stopped building them.

One culprit is outdated zoning. A century ago, it made sense to separate people’s homes from the noise and pollution of industrial-era workplaces. But today, these same regulations push daily needs farther apart and restrict both the supply and variety of housing available. Most of Eugene’s residential land is zoned for single-family housing alone, and our current land use plans call for more than half of new homes in the next 20 years to be single-family residential alone. And yet, by 2025, the majority of households will be without children. By 2030, 35 percent of all households will be a single person.

Another obstacle is that we’re often talking about the wrong things. We need to stop talking about “density” and start talking about neighborhoods and more inclusive communities. Moreover, one-size-fits-all Systems Development Charges (SDCs) encourage building larger — more expensive — houses. Many communities focused on affordability are rewarding developers for building more units within the same buildable envelope.

Because missing middle units are smaller, they can be more affordable by design, which might mean young people with entry-level jobs can get into the local housing market, or that your own parents can stay. They’re also designed to blend into the surrounding neighborhood and can provide a graceful transition from single-family homes to the commercial buildings and businesses along our busier corridors.

While Eugene’s housing affordability crisis has gained national attention, the entire country is grappling with this generational shift in the housing market. Baby Boomers are seeking to downsize while Millennials are trying to break into the market — and they’re both looking for smaller, more affordable housing within walking distance of shopping and public transportation, according to the Urban Land Institute and AARP. Or, as Parolek summed it up: “What the Millennials want, the Boomers need.”

Meanwhile, suburban single-family homes make up 90 percent of the current U.S. housing stock. Combine this market mismatch with the still-significant influence of the Great Recession’s housing market crash, and it adds up to a 35-million-unit shortage in the walkable housing desired nationwide. Here locally, we have our share of that shortage.

But we can do something about it — specifically, our building culture has the skills needed to do something about it. Over the past 10 years, Portland has taken concrete steps to eliminate barriers to missing middle types like backyard cottages, and the market has responded. With every step to build capacity and remove financial disincentives, Portland’s local industry of builders, architects and homeowner-developers focused on this smaller scale has grown in capacity and diversity.

According to AccessoryDwellings.org, Portland issued 615 permits for accessory dwelling units in 2016 — 20 times the average number of permits issued each year before Portland began waiving the SDCs for these units in 2010. They’re building almost as many small cottages as they are typical single-family homes.

Make no mistake: Eugene still needs single-family housing, market-rate apartments, mixed-use projects, and larger affordable housing projects — missing middle housing is not a silver bullet. But it can help provide some of the quality, variety, affordability, and accessibility our community has long lacked.