Density is the Holy Grail of New Urbanism, from creating new zoning for granny flats, rooming houses, townhouses, duplexes, fourplexes and backyard two-story rental houses in established neighborhoods to encouraging dense mixed use development on undeveloped or redeveloped land. The advantage of urban density and the idyllic effect of density has been the battle cry of urbanists and city planners for decades. However, very little has been said about the destructive force of density. For this reason I have made a list of two dozen ways adding density to a neighborhood diminishes and ultimately destroys a neighborhood one house at a time. Hopefully, if our City Council, planners and thought leaders are aware of the potential destructive force of density, they will pull back from the current call to blanket every neighborhood with more density.
1) Adding zoning density encourages existing neighborhoods to be torn down one house at a time. Adding zoning density provides opportunities for investors, speculators, and absentee owners to tear down existing homes and replace them with new denser housing types.
2) Adding zoning density to residential neighborhoods encourages absentee owners to replace homeowners, which destabilizes neighborhoods. Investors, speculators, and absentee owners will buy properties from homeowners and then rent them. These absentee owners will disinvest in properties, letting them deteriorate since they are speculating on selling the lots in the future for denser residential use. For instance, a home in the 90-year-old Mount Auburn neighborhood of 1,000 sf cottages might be projected as a lot for a duplex, fourplex, or a new home with a new 1,000 sf backyard rental house behind it. In this case, a speculator will not want to invest in maintaining a house that they plan to tear down or think a future buyer will tear down for higher density rental units.
3) Increasing density in a residential neighborhood increases crime. Increased density increases transience and turnover of residents in the neighborhood. Neighbors know a lesser percentage of people in the neighborhood. Long term homeowners are more protective of their neighborhood and the homes around them than are short-term tenants.
4) An increase in a neighborhood’s density decreases neighborhood involvement. One of the goals of New Urbanism is to have more neighborhood interaction. Density decreases neighborhood personal interaction and involvement.
5) Granny flats/backyard rental houses/ADUs deforest neighborhoods. A granny flat ordinance will inevitably cause 100-year-old towering trees that provide full canopies over standard 50‑foot wide lots to be cut down and replaced by backyard rental houses and concrete driveways and apartment parking pads. It will be necessary to cut down the trees to make room for backyard rental houses and to make room for the apartment parking pads. The rental houses and parking pads will add even more concrete to backyards, killing the root systems of trees even on the edge of the backyard.
6) Added density and granny flats/backyard rental houses will destroy the existing urban ecosystem. Additional density will destroy the existing habitat for urban wildlife, hawks, and predatory birds, egrets fishing in Koi ponds, songbirds nesting in understory trees, hummingbirds, butterflies and bees feeding and pollinating the lush backyard ecosystem.
7) The increased density of two-story backyard rental houses blocks breezes that flow through the established older neighborhoods. The detrimental effects of eliminating the cooling breezes drives people out of their backyards and back porches and inside to their air conditioned homes. This increases the air conditioning usage and cost for each home, along with having a negative impact on the environment.
8) Granny flats/backyard rental houses and increased density contribute to global warming. Rather than trees providing canopies over roofs shading houses, increased density removes the trees and adds more rooftops and more concrete to absorb heat and radiate back into the neighborhood and atmosphere. Again, more air conditioning is needed for every home when trees are not absorbing the heat and shading the homes. A leafy canopy over a roof reduces the amount of air conditioning a home needs. Extra concrete and rooftops absorbing and radiating heat increases the amount of air conditioning each home needs.
9) Increased density increases pestilence. Studies have shown that overbuilt and dense neighborhoods are much more vulnerable to the deadly small West Nile mosquito. The large and relatively harmless field mosquito is more prevalent in less dense neighborhoods while the West Nile mosquito is more prevalent in dense neighborhoods.
10) Granny flats/backyard rental houses increase flooding. Older established neighborhoods were not built for density or with sophisticated drainage systems. These older homes relied on the yard’s natural absorption, or water runoff to the alley to protect their primitive pier and beam foundations. Backyard rental houses allow lot surface to absorb water, creating more runoff that floods streets and creeks. Backyard rental houses would also trap heavy rains between the main house and back rental house. Even French drains that might be designed for new backyard rental houses still would not be enough to prevent the water of heavy rains from backing up under the 100-year-old houses supported by primitive 2’ surface piers, originally bois d’arc piers. A backyard rental house will also cause water that cannot be absorbed to run onto a neighbor’s property and under the neighbor’s foundation causing damage. The foundations and drainage systems of older neighborhoods were not designed for lots that have added to them granny flats/backyard rental houses/ADUs.
11) Granny flats/backyard rental houses create and intensify light pollution. Typically, two-story backyard rental houses will be surrounded by high wattage security lights beaming down from their eaves. Any house two or three doors down from it, next to it, or behind it, will find lights at night shining into their home. There is even a tendency for a backyard rental house to have more and higher wattage security lights than the main house.
12) Adding density, granny flats/backyard rental houses clog the streets with parked cars on the curb. The granny flat ordinance requires a backyard rental house to have the appropriate number of parking spaces. However, even if garage spaces under the rental house or apartment parking pads in the backyard are provided, tenants still need to get out of the narrow driveway. No longer can the homeowner park two cars in the driveway, as they would now be blocking tenants. As a result, at least two cars get parked on the street. As a practical matter, on a standard 50-foot wide lot that includes a driveway and a center sidewalk, there is only room for two cars to park in front of a house. Tree-tunneled streets with cars only periodically parking on the curb will become jammed with cars parked on both sides of the street. This is the reason why we see so many people in less desirable dense cities having to use parking permits in front of their own house or people fighting over parking spaces on their street.
13) Increasing density in established neighborhoods floods the market with new apartments, accelerating the decline and deterioration of older apartments. Absentee owners neglect the older apartments as they become more difficult to rent. New apartments in a neighborhood cost tenants more to rent, an increase of apartments reduces the value of homes in the neighborhood.
New construction is always expensive. A new apartment unit might even cost more to rent than the 90-year-old house it replaced. Adding density reduces affordable leasing opportunities for renters. Absentee owners will let the leftover older apartments deteriorate until they are torn down and cleared for a vacant lot or for new more expensive apartments.
14) Granny flats /backyard rental houses diminish the diversity of housing styles and sizes. To maximize the size of a rental house one can build in a backyard, one has to increase the size of the main house by either tearing it down and building a new one or popping the house up and expanding the original small house. As an example, there would be economic pressure to put a second floor on a 980 sf bungalow in Junius Heights and make it 2,000 sf to allow a 500 sf granny flat to be built over a two-car garage. The new granny flat would cost more to rent per month than the original 980 sf house before it was expanded. A backyard rental house would not provide a gain in the number of affordable houses, but it would cause a decrease in the number of small affordable homes. A granny flat ordinance will gradually put pressure on investors and homeowners houses to expand houses or tear them down and replace them with 4,000 sf homes in order to allow a 1,000 sf rental house in the backyard. Since backyard rental houses can be no larger than 25% of the main house, there will be a trend for all the main houses to become a similar size to maximize the rental house opportunities in backyards.
15) Increasing zoning density in a neighborhood accelerates gentrification and displacement. The surest cause of displacement is tearing down an existing home. Adding zoning density increases the pressure on individual absentee owners and investors to tear down existing homes one house at a time. Older homes, whether in Highland Park or South Dallas, often have no or little value over the cost of the lot. Adding zoning density and allowing granny flats encourages new construction, which is always expensive. New construction, which is more expensive than existing homes, contributes to gentrification and displacement.
16) Homeowners and renters prefer to live next to single-family homes rather than next to apartments. Adding zoning density to neighborhoods makes them less attractive to both homeowners and renters. Less attractive neighborhoods attract less desirable tenants. This creates a downward neighborhood spiral. Less attractive tenants make the neighborhood less attractive for homeowners.
17) Higher density attracts absentee owners. Lower density attracts homeowners. Density attracts renters; density repels homeowners. A good example is the comparison of Northern Hills to Munger Place. Northern Hills is a neighborhood built at the same time and with similar size homes found in Munger Place and Swiss Avenue that are the same distance from downtown. Northern Hills is closer to Central Expressway than Munger Place is to the I-30 expressway. In the 1960s Northern Hills might have declined as people were leaving Dallas close-in neighborhoods, but it never fell into the condition of derelict divided up rent houses found in Munger Place. This is because Northern Hills was not over-zoned for apartments and additional density. Homeowners are attracted to homes and are repelled by carved up rent houses and apartments like the ones that were built on Gaston Avenue in the 1960s, a street that ran through Munger Place.
18) Density discourages lending on single-family homes. The higher the percentage of homeownership in a neighborhood, the easier it is to get a loan. We even see in condominiums, the higher the percentage of owner occupied units in the condominium, the easier it is for a condominium unit buyer to obtain a loan.
19) For many new urbanists rooming houses are the dream density. However, rooming houses are like convenience stores in food deserts. They are convenient but they are very expensive and they offer very little nourishment. Without nourishment neighborhoods wither.
20) Adding density disrupts neighborhoods. Neighborhoods are fragile and need to be nourished. Neighborhoods either get stronger or they get weaker and decay. In the neighborhoods the city wants to protect and make stronger, the city should install new sidewalks, curbs, street lights, and plant parkway trees. They should not add more apartment zoning that further disrupts the neighborhood.
21) Adding density to established neighborhoods draws mixed-use developments away from neighborhoods in need of investment. Developers, investors, and builders are attracted to stable neighborhoods. If a builder has the choice of building a duplex or a fourplex in a stable neighborhood or a deteriorated neighborhood, they will choose the stable neighborhood. If Dallas adds zoning density to stable neighborhoods, this becomes a magnet for builders and investors to build apartments in these stable neighborhoods. Just as significant, it draws investors and developers away from nearby less desirable neighborhoods that have vacant lots and cheaper lots and are already zoned for apartments. If the established neighborhoods are protected from additional density, builders will invest in the deteriorated neighborhoods that have mixed-use zoning. New development in deteriorated neighborhoods helps the adjacent stable neighborhoods.
22) Adding zoning density increases oversupply of apartments and oversupply of apartment zoned areas. On the same day the Dallas Morning News reported there was a projected oversupply of 45,000 apartments being built in the Dallas area, the Dallas City Council passed the granny-flat ordinance to pave the way for tens of thousands of more potential apartments to be built in the backyards of single-family homes. New construction is expensive. It is hard to imagine a more costly way to build a 250 sf to a 1,400 sf rental house than to have a homeowner build a small one-off rental house squeezed onto a backyard of a standard 50 ft x 150 ft lot. Backyard rental houses increase the oversupply of expensive apartments in Dallas and decrease the desirability of single-family neighborhoods where the backyard rental houses are built.
23) Adding density to neighborhoods makes planners feel good and homeowners feel bad. Planners felt good about over-zoning neighborhoods with apartment zoning in the 1950s and early 1960s. Planners felt the same way about mixed use over zoning in the late 1970s when they recommended 15 separate zoning districts of duplexes, triplexes, fourplexes, townhouses, and apartment buildings in an area where 2,000 property owners petitioned that this entire area be down-zoned to single-family zoning. Now, under the name of New Urbanism, planners want the same over zoning, allowing backyard rental houses and more mixed use zoning in single-family neighborhoods. Planners want to rezone existing neighborhoods with the higher density of mixed residential uses. This higher density zoning theory makes planners feel good. The result of this up-zoning makes homeowners feel bad.
24) Upzoning exacerbates the deterioration of mixed-use neighborhoods. In older neighborhoods with mixed residential densities, upzoning exacerbates the deterioration of the neighborhood. We saw the disastrous effects of upzoning in Old East Dallas. This is also the reason City Council member Rickey Callahan objected to the granny flat ordinance. He understood the negative impact of allowing backyard rental houses in his Pleasant Grove neighborhoods that he was trying to stabilize and improve. A trend for more single-family homes and less density instills optimism and a potential resurgence of the neighborhood.
I have seen firsthand the negative effects of added zoning density to single-family neighborhoods and the positive effects of eliminating over-zoning. Since college I have lived in a mixed-use, dense, culturally diverse, and architecturally interesting, distressed neighborhood. While it went from being identified by the city as the worst neighborhood in Dallas to one comprised of three historic districts, newcomers to the area still try to decide if the neighborhood is on its way up or down because they see so many apartments. While I enjoyed the vibrancy, danger, and colorful characters in the neighborhood, the salve to the constant urban discomfort was the knowledge that since the neighborhood was rezoned single-family, the trend every year would be fewer apartments, more homeowners and greater stability. Hundreds of people moved into the neighborhood with the knowledge that every day the neighborhood was becoming tamer and it would improve as density gradually decreased. Very few deteriorated inner city neighborhoods in the country have meaningfully improved. Munger Place Historic District in Old East Dallas would have continued to deteriorate and the houses gradually be torn down for decades if the over-zoning had not been changed to single-family zoning.
Dallas is a city with thousands of vacant lots, undeveloped land underdeveloped land, all ripe for new development. I join my New Urbanist friends in desiring mixed-use neighborhoods, high density areas, additional parks, and greater opportunities to walk or ride a bicycle, which I exclusively relied on for transportation for years. Further, I want to join them in wanting to rethink the highways that have cut through neighborhoods. Years ago I worked to stop the proposed crosstown expressway that would have connected I-30 to Central Expressway via Munger Boulevard. At the same time I even went a step further and successfully advocated Fitzhugh Avenue and Collette Street become two-way roads again instead of one-way couplet. I have always embraced enhanced city vibrancy. I recall my good friend and client, James Shinn, the former director of International Affairs for the City of Dallas, who said at his SMU Town and Gown talk that he gave over 20 years ago that if Dallas wanted to be an international city, the most important thing it could do was put a deck park over Woodall Rodgers Freeway which would create downtown vibrancy. Giving it some thought, I agreed with this premise. I thought at the time this was profound. Having worked with me when I sold his home, Jim Shinn thought I would be able to help shepherd this deck park idea for the city. In fact, he said he could offer me a contract for $9,500 out of his department’s budget without having to seek City Council approval for this amount. I was more flattered by his request to help with this project than a request from any homeowner to sell their multi-million dollar home. As much as I would have loved to have committed to this project, even without compensation I knew that it would take full-time commitment and could not afford to take a sabbatical from my real estate business.
It is also of interest that Jim Shinn and his wife Patricia had been in the diplomatic corps and had the opportunity to live in many of the most beautiful and vibrant places in the world. He understood what would bring a vibrancy to downtown Dallas that would be attractive to people around the world. He also lived in Turtle Creek Park, which I have sometimes referred to as my favorite neighborhood of Dallas. It is the least dense urban neighborhood in Dallas, with only 35 small houses on large lots, with curving streets, forests and hills framed by creeks and trails and located only 15 blocks from the Central Business District. Dallas can remain the most attractive city in the country if it continues to increase the vibrancy of downtown and vibrancy with developments like Trinity Groves and the Bishop Arts District while simultaneously protecting and celebrating the low density, bucolic, close-in residential neighborhoods of Dallas like Turtle Creek Park. Redeveloped neighborhoods and protected neighborhoods can play off one other as they did in the 1980s when David Fox built Bryan Place, a mixed-use residential development on the boundary of the restoration area that now consists of three East Dallas historic districts.
A good rule of thumb for density — if a city wants a neighborhood developed or redeveloped, upzone it and add density.
If a city wants to protect an established neighborhood, downzone it and encourage the trend towards less density.