There are other residence options besides single-family housing. Often, cities outlaw everything except for single-family residences, limiting one unit per lot. Due to this overabundance of single-family housing, today’s young cities do not hold enough density for growth. Below, I’ll talk about five alternatives, where they’re applicable, and their benefits.

Before we can define each housing type, we should first understand why single-family housing is so prevalent. Euclidean Zoning, or Single-Use Zoning, was introduced in the 1930s and 1940s. By restricting housing to zones exclusively intended for housing, cities could no longer group together commercial and residential building types. This leads to neighborhoods without close access to commercial areas and a single-family sprawl found in Tulsa and cities elsewhere. By introducing more residential options, commercial areas can be reintroduced to these neighborhoods while maintaining the same - if not higher - levels of population density.

Duplex

A duplex is when two residences are on a single lot.

They're usually attached, but they could be set up to where they're separated. The typical ownership model is that the primary owner will live in one, and then the second unit will be rented. This is a good model for generational wealth because that unit can usually pay for the mortgage of the duplex. In the attached format, it's essentially a big house.

Duplexes are rarely zoned outside of residential areas and crop up in areas that provide more density than single-family housing can accommodate. The increased density works well with commercial or Main Street areas closeby.

Fourplex / Quad

A fourplex, or quad, is when four residences are on a single lot.

There are different configurations for quads, such as the 1+1+1+1 where all the units are on the ground floor and the doors face the sides of the lot. Another is the 2-over-2, with two units on the ground floor and two units stacked above. This configuration is most common in older turn-of-the-century neighborhoods from the late 1800s and early 1900s.

Quads are typically always rental and the owner doesn't live there, though they can. There's a great funding program by FHA (Federal Housing Administration) that allows you to owner occupy up to four units. A quad is typically in the same type of plot. But this is almost always four units in the same building.

Quads follow much the same reasoning as duplexes have in zoning and opportunity to commercial areas.

Accessory Dwelling Unit (ADU)

An accessory dwelling unit is a residence independent of the main house on the lot

It’s usually referred to as a granny flat, or a laneway cottage, or an alley house. It's can be a garage apartment. Usually is the most traditional form is just a house that's outback.

Tulsa is currently getting more friendly to ADU’s and is allowing them by right in a couple of zoning districts.

ADU’s are almost exclusively owned by the owner of the property and rented out to others.

Townhomes

Townhomes are a single-family unit that shares at least one wall with an adjacent unit. These tend to be made up of three or more units.

Townhomes are both rented and owned. In owning a townhome, you typically own the dirt that sits under the building as well. In contrast with something like a condo, you don't own the dirt; you also pay a more substantial HOA (Home Owner’s Association) fee. A townhome typically has an HOA but it’s to take care of the shared amenity sets. Amenities include shared green spaces, storage units, bike racks; in more progressive areas, there may be shared solar panels and thermal loops, or community gardens.

Carport garages are common for townhomes, as is rentable parking for those who want it. With this approach, areas with townhomes tend to be more walkable than single-family zones. Biking is more common in these areas.

Townhomes are a rare product within places that were developed after the advent of the car. Much of the South doesn't have many townhomes. In areas with accelerating population growth, like Denver or Dallas, townhomes are quite common in new construction. Still, they tend to be in more residential areas, even within an urban context. Within a walkable neighborhood, you may have one street that is more retail or restaurant oriented, with the next street more residential oriented.

An offshoot of the townhome is the Live-Work Unit, where the first floor operates as commercial use that is public-facing. The code treats them the same as they do townhomes. This model is what we see in most main streets where the shop owner lives above the shop itself. It's now coming back into some level of popularity because people are realizing the work-life balance - or work-life integration- is financially advantageous. You can have one mortgage for the whole thing, but your business pays rent to yourself, essentially.

Cottage Courts

A cottage court is typically six or more individual houses on a single lot.

These are detached houses, but they're typically small in nature: often in the range of 800 to 1000 square feet. If they were attached, they would be classified as townhomes or apartments. Factors like the lot’s location, whether there’s alley access, if there’s street frontage available, and the existing context in the neighborhood all affect whether the cottage court would be the right decision over a duplex or quad.

Cottage Courts can be for rent or for sale. In renting, a developer would own the court and you would pay rent and have access to the shared amenities that are available. Ownership is similar to condos where you own your unit but you pay HOA fees and other dues for upkeep and maintenance of the shared amenities. There’s also the hybrid model where you own your unit on a fee simple lot. A fee simple lot is where you own the lot your house sits on, but you pay into a homeowners association for the shared amenities (if available). These amenities can mirror those found in townhomes.

One of the pioneers of cottage courts is the architect Ross Chapin, who has a book on the topic. Cottage Courts benefit from communal developments that are not seen in single-family housing, where shared amenities lead to knowing your neighbors by their first names and being a part of their day-to-day lives.

Oregon and Washington have passed ordinances that end single-family zoning, as has Minneapolis and other cities. Although single-family housing is seen as safe and quiet, it is not the one-size-fits-all solution to Tulsa and other cities. It does not keep up with rising populations.

Change in housing doesn’t happen immediately, the market needs time to move in. If you don't build housing but you have population growth, it shocks the system and extraordinary measures are needed to correct it. If you start at the beginning, you can comfortably allow for that density to build up over time while still allowing for people to move in and have that population growth. That benefits everyone.

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