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  • Writer's pictureJon Mitchell

Why I voted for two-family housing

Updated: Oct 7, 2023

Depictions of housing types, courtesy of the Town's Urban Designer

In June 2023, the Town Council adopted an amendment to the Land Use Management Ordinance to permit modestly-sized two-family housing configurations in many (not all) areas previously reserved for detached single-family houses (i.e., "R-1" zones).

Here are some key facts about the amendment:

  • It permits duplexes no bigger than 3,000 total square feet (i.e., the sum of both units), whereas single-family houses have no such limit.

  • Standard height and setback requirements still apply.

  • Small accessory units were already allowed in R-1, since at least 2017. There are over 60 of them around Town.

  • The amendment does not impact neighborhood conservation districts (NCDs) and does not override applicable covenants against duplexes.

  • If a duplex is built, it will be subject to stronger tree canopy and stormwater protections than single-family houses.

  • Duplexes may have no more than 4 unrelated residents per unit, and no more than 4 parking spots combined (to prevent “student stuffers”). Single-family houses have no such limits.

I want to briefly explain why, as Chair of the Planning Commission, and as a homeowner whose neighborhood is impacted, I voted to recommend this change. For me, it came down to a combination of factors, including the historical roots of single-family zoning, evidence from other places that abolished it before us, and the realities of our current housing market.

A problematic history

One way to approach the question of allowing two-family housing in R-1 is to ask why we have single-family zoning in the first place. It's more common in some other parts of the world – and in some parts of Chapel Hill itself (including, for example, our Cameron-McCauley Historic District) – to locate different housing types in close proximity. In addition, urban planners nowadays seem generally to disfavor single-family zoning, for a variety of reasons. What originally caused so many U.S. towns to favor it?

In his 2017 book The Color of Law, Richard Rothstein demonstrates that the early proliferation of single-family zoning in the United States, going back to the middle of the 20th century, had a lot to do with keeping housing costs in particular neighborhoods above a level Black folks could afford. The inherent cost of building detached dwellings, combined with generous minimum lot size requirements, helped keep Black residents out of middle-class white neighborhoods. Indeed, single-family zoning was at one time considered an effective way of circumventing federal restrictions on housing discrimination. This helps explain why it became enshrined in many suburban zoning ordinances (via "model" zoning codes), and then stayed there, even as the memory of its original purpose faded. Under different circumstances, it's conceivable we wouldn't have single-family zoning.

This history gave me pause, and caused me to reflect on the fairness dimension of single-family zoning in today's context – the way it can limit housing options, and by extension exclude people, and to what end. I'll come back to this.

Underwhelming impacts elsewhere

Chapel Hill is not an especially early mover in this area. We have the benefit of empirical evidence from a host of other cities that abolished single-family zoning before we did – cities like Minneapolis, which abolished single-family zoning in December 2018, and our neighbors Durham and Raleigh, which did so in October 2019 and July 2021, respectively. What consequences ensued?

It turns out that allowing duplexes, triplexes, and even quadplexes (the latter two of which Chapel Hill is not allowing) in single-family neighborhoods has yielded little actual construction activity, at least in the short term. Presumably that's because buying and tearing down a perfectly good house to build something slightly larger and more partitioned rarely pencils out for developers. While information about average impacts can't tell us the distribution of impacts on specific neighborhoods, such as neighborhoods near UNC campus, the data suggests that, in general, the impacts on Chapel Hill will unfold slowly.

The Journal of the American Planning Association recently devoted an entire issue to essays by academics and planners for and against single-family zoning. A common thread of the arguments for single-family zoning is that abolishing it just doesn't bring much change, yet the very idea stirs great controversy.

At any rate, this information on the experiences of other cities somewhat alleviated my concerns about unintended consequences – apart from political ones, which are above my pay grade (of zero) on the Planning Commission.

It's not a panacea, but it will help

So far I've said nothing about the housing cost challenges faced by Chapel Hill, our region, and the United States in general. That's the larger context of this discussion. We have UNC assistant professors living in Pittsboro, large numbers of UNC graduate students living in Durham, because of housing costs. Let's be realistic: the Town lacks the tools to eradicate that problem. We do have some tools to lessen it. If we can find ways to use those tools judiciously, I believe we should.

How does this particular change help? Worn-down houses are eventually torn down. They can be replaced with larger single-family houses (which is in fact happening in Chapel Hill), or they can be replaced by two-family configurations – at the market's discretion. In general, the cost per unit to produce the former is relatively higher, due to land costs alone.

Ah, but haven't we seen anecdotes from Durham and Raleigh that show these changes can lead to very expensive units? Sure, but this objection somewhat misses the point. The changes were designed to yield housing that is less expensive in relative terms, not necessarily "affordable" in absolute terms to households making, say, 80% of area median income. Before the recent changes, the Town's zoning system favored a $1 million single family house over two $600,000 duplex units on the same parcel. Now it doesn't.

Room for nuance

Almost nothing in housing policy is simple. The strongest argument I've heard against the changes is rooted in Chapel Hill's specific circumstances. The argument is that the changes could disrupt the delicate balance that enables neighborhoods predominantly occupied by families, rather than undergraduate students, to thrive on the fringes of UNC campus. There's a lot to unpack there, but for present purposes, I'll simply acknowledge that this argument is coherent and made in good faith. It's reasonable for families that bought houses in quiet neighborhoods to want them to stay that way.

The final changes partially address this concern by limiting the number of unrelated people per unit (4), and by limiting on-site parking (4 per property). I personally suggested these provisions to Council members, back in January.

Of course, there's still a risk that some residents will experience negative impacts traceable to the changes, which concerns me. The implications of allowing two-family configurations in a college town are, in fact, rather complicated.

Weighing the arguments

The professor who taught my "evidence" class in law school (many years ago) used to say that the outcome of many cases hinges on which side bears the burden of proof. Often a plaintiff loses not because their version of the facts is obviously wrong, but because their version is not obviously right, and the burden is on the plaintiff to prove the facts.

This is one way to understand our recent public debate about two-family housing. If the burden is on the Town to demonstrate, to a high degree of certainty, that the changes will have significant positive consequences and insignificant ill effects of any sort, that's a hard burden to overcome. I understand why those who allocate the burden this way may be dissatisfied with the outcome.

I approach it the other way. We know that:

  • Many other communities successfully mix different housing types in close proximity;

  • There's problematic history here;

  • Similar changes have brought about only gradual impacts elsewhere;

  • A shortage of "missing middle" housing is pushing many of those who work or study in Chapel Hill to surrounding towns; and

  • The changes will tend to decrease housing costs relatively speaking.

Knowing these things, if we're still going to prohibit two-family configurations in wide swaths of Town, we should be able to demonstrate why this prohibition is reasonably necessary to some end that we can articulate. Residents made thoughtful, serious arguments on both sides. But in the end, I don't think such a demonstration occurred.

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