Eric Kronberg is the founder of Kronberg Urbanists + Architects, a firm dedicated to helping communities create flourishing neighborhoods. To do this, his team looks at every side of the development process - finance, civic, design, and infrastructure - and weighs them against the desires of the community. People want stable services, low taxes, and low density, but those priorities often come with difficult trade-offs. Kronberg frames this tension as a question of abundance versus scarcity: how can we design our communities so that more people share in the benefits?
Outdated Codes and Today’s Challenges
Our communities look very different than they did when most zoning codes were first written. Back in the 1950s, 43% of households were traditional nuclear families and only 9% were singles living alone. Today, that number has nearly flipped: only 20% of households are nuclear families, and by 2030, 83% of households will likely have no children. By 2050, nearly a quarter of the U.S. population will be senior citizens.
Family sizes are shrinking, but houses keep getting bigger. In 1950, the average new single-family home was under 1,000 square feet, less than 300 square feet per person. By 2017, household sizes had fallen while house sizes ballooned, leaving Americans with more than three and a half times the space per person compared to the mid-20th century.
This trend is no accident. It’s the direct outcome of single-family zoning regulations. Builders are not to blame; they simply build what’s legal. The result? Starter homes, once a staple of the American dream, have all but disappeared. In the 1970s, nearly 40% of new homes were under 1,400 square feet. Today, that number has dropped to just 8%.
The High Cost of Low Density
Single-family-only zoning is more than just a preference for one type of housing; it’s a policy of legally mandated scarcity. That means fewer housing options, higher prices, and residents like aging seniors who are “over housed” in homes too big for their needs but have no downsizing options.
Low-density development also requires massive infrastructure - streets, sidewalks, utilities, police, fire, and schools - to serve a very small number of households. Property taxes from single-family subdivisions never cover the cost. More housing choices on the same land change that equation. Even a duplex or ADU can generate up to four and a half times more tax revenue per acre than a single-family home. In walkable neighborhoods near shops and services, the benefits multiply.
The contrast is stark: a suburban big-box store might generate $800,000 to $950,000 per acre in tax value, while mixed-use, walkable neighborhoods can bring in $9 to $10 million per acre. That tenfold increase gives cities the resources to invest in stormwater systems, street trees, and public spaces that improve quality of life for everyone.
Cities that stick with the low-density, single-family model are locking themselves into scarcity and financial strain. Those that embrace more housing choices and walkable development are choosing abundance and setting themselves up for lasting success.
The Burden of Parking Requirements
Parking rules are another form of mandated scarcity. In traditional main street districts, parking was a shared amenity alongside trees, sidewalks, and neighborhood parks. Suburban zoning flipped the model - every building required its own parking lot, setbacks, and stormwater retention.
The result is staggering inefficiency. For offices, retail, or restaurants, half of a site can be consumed by parking. Asphalt doesn’t generate tax revenue - buildings do. By mandating so much parking, cities reduce housing supply, cut revenue, and spread everything farther apart.
Some cities are starting to change course, removing parking minimums and letting the market determine how much is needed. Without reform, walkable, abundant neighborhoods simply can’t be built.
The Financial Reality of Building Housing
Kronberg illustrated how building costs make attainable housing difficult. Research from UCLA’s Housing Voice podcast shows how costs escalate depending on building type, especially once structured or underground parking is required. He offered the example of an 800-square-foot apartment. Even when looking only at the vertical building cost and parking, you capture just half the true cost of delivery. Once you add land, fees, and permitting, the cost grows further.
Developers use a simple rule of thumb: $1 in monthly rent can only support about $100 in project cost. Rising interest rates shrink that margin even more. If the numbers don’t work, the housing doesn’t get built.
To bring costs down, Kronberg suggests building smaller units, providing less parking, and focusing on moderate densities (20 to 50 units per acre) that balance efficiency and affordability. ADUs can help too, but financing rules make them difficult, since most households must pay cash to add one.
Policy reforms like reducing minimum lot sizes, allowing fee simple ownership of ADUs and duplexes, and easing subdivision rules could expand attainable options. Even a simple up-down ADU on a standard lot can double housing without doubling land costs.
Why Smaller Lot Subdivisions Matter
Kronberg shared a case study from Atlanta. On a standard 8,250-square-foot lot, building one two-bedroom home came in at 145% of AMI, unaffordable for the neighborhood. Adding an ADU reduced monthly costs but required a $100,000 cash down payment, putting ownership out of reach.
When the lot was split to allow two homes with ADUs, affordability improved, but down payments remained a barrier. The real breakthrough came with fee simple platting, subdividing the lot into smaller parcels. The two-bedroom homes dropped to 110% of AMI, and homes with ADUs reached 85% of AMI which are levels attainable for local families.
Small-lot subdivisions don’t just expand ownership opportunities; they also enable local builders to participate without shouldering the costs of managing rentals.
Housing + Transportation: The Hidden Cost Burden
Housing costs can’t be separated from transportation. HUD suggests households shouldn’t spend more than 50% of their income on housing plus transportation, but car dependence makes that nearly impossible.
AAA estimates the true cost of owning a car at $9890 to $1,250 a month. For someone earning $30,000 a year, transportation should cost no more than $500 a month. In reality, even one car requires an income of at least $53,000 to avoid being cost burden. For two cars, the number doubles.
Historically, American towns built walkable, mixed-use neighborhoods that paid for themselves. Today, those patterns are illegal in most places, replaced with car-dependent sprawl that drains city budgets and fuels opposition to growth.To build vibrant, inclusive communities, we must legalize the very development patterns that made our favorite neighborhoods possible.
Building Codes: IRV vs. IBC
Building codes also shape what’s possible. The difference between the International Residential Code (IRC) and the International Building Code (IBC) often determines whether a project is affordable or out of reach.
A duplex with an ADU falls under the IRC, designed for single-family homes and small housing. It’s straightforward and cost-manageable. But a triplex falls under the IBC - the same code applied to hospitals and high-rises. That shift requires engineering, civil drawings, sprinklers, stormwater systems, and accessibility upgrades that add hundreds of thousands of dollars in costs.
Some states have begun reforming these rules. Tennessee and North Carolina now allow triplexes and fourplexes under IRC standards. Kronberg’s team has found that townhome-style designs built under IRC can deliver more affordable units in the same footprint as costlier IBC projects.
If we want more missing middle housing, we need codes that scale with building size. Otherwise, unnecessary costs will continue to prevent small projects from being built.
Finley Street Cottages: A Zoning Success Story
The Finley Street Cottages project in Atlanta shows how zoning reform can deliver results. Built entirely by right, the site includes 16 rental units with a mix of guest suites, ADUs, and primary homes serving different income levels - from 60% AMI to market rate. What’s notable is that none of it required subsidies. Atlanta’s parking flexibility, along with creative site design and stormwater management, made it possible to add a variety of homes and community amenities on one block.
Stock Plans and Toolkits
Changing zoning alone isn’t enough. Builders and nonprofits often need help knowing what to build. Kronberg’s team has developed stock housing plans: pre-designed, ready-to-build options ranging from micro-studios to missing middle housing. Cities like Tulsa are already using these pre-approved designs to speed up construction.
But stock plans are only part of the solution. To truly move the needle, communities need subdivision reform, smaller lot sizes, and multi-unit infill built under IRC. Paired with incremental zoning changes, these tools can deliver new housing in ways that feel approachable to residents and achievable for builders.
Moving Forward
Kronberg’s message is clear: the housing crisis can’t be solved one town at a time. Local reforms are important but often slow and politically risky. State-level action is essential to modernize codes, reduce unnecessary costs, and expand attainable options.
Reforms like exempting sprinklers in townhomes, legalizing small-lot subdivisions, and supporting flexible housing types for seniors and families could open doors for more people. Pilots and pre-approved plans can build trust, show what’s possible, and lower the risk of change.
Washington, Texas, Oregon, and other states provide models. None solved their housing challenges in one legislative session, but through persistence and recalibration, they made real progress. The same can be done elsewhere - before the crisis deepens further.
Eric Kronberg’s presentation highlights a central truth: our housing challenges are not inevitable, they are the result of rules we can change. By rethinking zoning, right-sizing codes, and adopting policies that encourage smaller, more diverse housing options, communities can move from scarcity to abundance. The tools exist, the models are proven, and the path forward is clear.
