This week we continue with guest blog posts from our Summer 2024 TURC students’ research project. Each student was challenged to write a brief post that showcased an element of their research from this summer, in addition to an original visual representation of data they have been analyzing. Students will present their full research project on August 9th from 1-2pm (Helmerich Hall, Room 219). The presentation is open to the public and you can find more information and RSVP here: https://pp.events/a8l1nMpb
Today’s guest blog is by Katrina Henderson, a rising sophomore in the Collins College of Business. Katrina has focused this summer on residential and commercial building permit applications and completions in the city of Tulsa. You can contact Katrina at keh3958@utulsa.edu or connect with her on LinkedIn at: https://www.linkedin.com/in/katrina-henderson-7ab429282/
Introduction
For my summer TURC research project, supervised by Dr. Meagan McCollum, I focused on examining building permit data in order to investigate recent housing development patterns in Tulsa County. The particular impetus for my inquiry is a recent study released by Housing Solutions Tulsa, a nonprofit organization dedicated to reducing homelessness. This study predicts the need for 13,000 housing units in Tulsa over the next ten years. My research lays the groundwork for determining where and how to most effectively encourage this needed development.
In this blog summary, I will first describe my research process and share its resulting data, then briefly analyze that data, and finally offer suggestions for future research.
Research Process & Data
In order to examine recent development patterns in Tulsa, I gathered building permitting data for Tulsa County between the years of 2018 and 2024, inclusive. Before mapping and analysis I cleaned the data, removing permits with missing information. I then analyzed and compared, in each zip code region (1) the number of completed permits (meaning building permits that resulted in finished developments), with (2) the number of expired permits (meaning permits for projects that were never completed).
I first compared completed single-family permits with expired ones, the results of which are shown in Figure 1.
Figure 1 – Completed Single-Family Permits (left) and Expired Single-Family Permits (right). Each map section is labeled with its corresponding zip code, and the legend indicates the number of permits completed or expired, respectively.
I then made the same comparison (completed and expired permits) for multifamily permits, as shown in Figure 2.
Figure 2 – Completed Multifamily Permits (left) and Expired Multifamily Permits (right).
Finally, I compared the number of completed single-family and multifamily permits for these years (Figure 3), and then compared the same for expirations (Figure 4).
Figure 3 – Completed Single-Family Permits (left) and Completed Multifamily Permits (right). Please carefully note the respective legend, as there are many more single-family permits than multifamily.
Figure 4 – Expired Single-Family Permits (left) and Expired Multifamily Permits (right).
Analysis
First, I analyzed completed and expired single-family development permits (Figure 1). While completed single-family permitting is spread throughout Tulsa County, there is a relatively large concentration of these permits in zip code region 74008. Interestingly, that area also has a relatively large number of expired permits. In contrast, region 74134—which also has a relatively large amount of completed permits—has substantially fewer expired permits. Additionally, the zip code regions adjacent to region 74134—specifically regions 74145, 74146, and 74012—have no expired permits. Thus, in order to improve the completion rate in zip code region 74008, it may be useful to analyze the development practices and regulations in these more successful completion regions. Furthermore, zip code regions 74055 and 74116 have more expired permits than completed permits—indeed, these areas have no completed permits. If practices from the more productive zip code regions were applied, it might help improve these permit completion rates.
Next, I examined the number of completed and expired multifamily permits throughout Tulsa (Figure 2). Overall, multifamily development looks to be concentrated in the heart of Tulsa County. Notably, in zip code regions 74106 and 74115, there were no completed permits, only expired ones. By contrast, zip code region 74133 had no expired permits and one of the highest numbers of completed permits. Once again, it would be useful to investigate the development environment in both areas, evaluating if practices from the more productive area could be applied to those areas with weak completion rates.
Finally, I examined the differences between new single-family and multifamily permitting (Figures 3 and 4), identifying two key insights. First, there are far fewer multifamily permits, both completed and expired. While multifamily developments naturally contain more housing units, there is still a vast gap between these figures, especially as a particular multifamily unit might not be especially large. Given the reported housing need, including a large number of affordable units, multifamily housing might need to play an increased role in the Tulsa housing market. Second, there seems to be little regional overlap in single-family and multifamily development activity. For example, while zip code regions 74107 and 74133 exhibit larger numbers of completed multifamily permits, they have far fewer completed single-family permits. Likewise, while zip code area 74134 has a relatively high multifamily permit expiration rate, it has one of the highest single family completion rates. Again, this might be caused by a variety of factors, including zoning laws or other land-use regulations.
Further Work
The next step, then, is to investigate the causes for these development patterns across zip code regions. In particular, I recommend investigating three categories of possible cause: physical limitations, legal regulations, and demographic differences.
First, physical limitations, such as the available building space, may naturally determine what kind of development builders are currently favoring. Land availability, and basic costs therefore, will naturally impact what types of residences builders will seriously consider. Likewise, legal regulations may impact current development differences. Zoning and other land-use regulations determine where certain developments are allowed, possibly causing concentrations of certain types of housing in different regions, including perhaps making some developments more destined for failure if those regulations are poorly suited to other realities. Finally, regional demographic differences—such as area median income, age, race, and education level—could also impact development patterns. In short, my work lays an important foundation for these questions, but it leaves critical questions for further research.