Tag: HUD

Allowing ADUs across Chicago: it’s never been more real

tl;dr: sign the petition so I can send the zoning committee the biggest marker of citywide support for citywide ADUs, and then call your alderperson on Monday to ask them how they plan to vote

Mayor Johnson indicated earlier this week that he is interested in legalizing ADUs citywide next week. Fran Spielman reported in the Chicago Sun-Times that he remains steadfast in ensuring that the option is available in all residential parts of the city. To that effect, he plans to submit a substitute ordinance at the next zoning committee meeting on Tuesday, July 15. 

ADUs were re-legalized in Chicago starting on May 1, 2021, in a pilot program available to property owners in five areas of the city. The pilot program turned four years old two months ago.

An ordinance introduced by Alderperson Lawson (44th Ward) over two years ago would dissolve the pilot areas and allow ADUs across the city and make other program fixes. However, the proposed ordinance requires that property owners in certain zoning districts obtain permission from the Zoning Board of Appeals before being able to apply for an ADU building permit.

While Lawson has argued that the votes have existed to pass his version, the mayor’s position is that that difference in treatment based on a property’s zoning district, which alderpersons can change, could continue the problem that the U.S. Department of Housing and Urban Development (HUD) found in October 2023.

I think that the mayor’s forthcoming ordinance is likely, like Lawson’s ordinance, to allow ADUs in all zoning districts (including existing residential buildings improperly zoned into M districts), allow both a coach house and an interior ADU on the same property, and allow existing parking to be removed so ground-level accessible coach houses can be built. In addition, I think it’s possible that the mayor’s version could keep some of the pilot program’s owner occupancy and maximum ADUs per block standards to ensure political feasibility in City Council.

After nearly eight years of ADU advocacy – participating in a task force during a previous mayor’s administration, presenting on panels, sharing ADU data with journalists and the public, and garnering support for a geographic expansion of ADUs in the city and Illinois – my primary interest is honing in to ensure that an ordinance legalizing ADUs across the whole of Chicago passes.

Take action: I’d like for every reader to sign this petition, created by Abundant Housing Illinois, to show the zoning committee and City Council that there is widespread support for ADUs.

Contacting your alderperson directly on Monday would be a bonus.

Working with ZIP code data (and alternatives to using sketchy ZIP code data)

1711 North Kimball Avenue, built 1890

This building at 1711 N Kimball no longer receives mail and the local mail carrier would mark it as vacant. After a minimum length of time the address will appear in the United States Postal Service’s vacancy dataset, provided by the federal Department of Housing and Urban Development. Photo: Gabriel X. Michael.

Working with accurate ZIP code data in your geographic publication (website or report) or demographic analysis can be problematic. The most accurate dataset – perhaps the only one that could be called reliably accurate – is one that you purchase from one of the United States Postal Service’s (USPS) authorized resellers. If you want to skip the introduction on what ZIP codes really represent, jump to “ZIP-code related datasets”.

Understanding what ZIP codes are

In other words the post office’s ZIP code data, which they use to deliver mail and not to locate people like your publication or analysis, is not free. It is also, unbeknownst to many, a dataset that lists mail carrier routes. It’s not a boundary or polygon, although many of the authorized resellers transform it into a boundary so buyers can geocode the location of their customers (retail companies might use this for customer tracking and profiling, and petition-creating websites for determining your elected officials).

The Census Bureau has its own issues using ZIP code data. For one, the ZIP code data changes as routes change and as delivery points change. Census boundaries needs to stay somewhat constant to be able to compare geographies over time, and Census tracts stay the same for a period of 10 years (between the decennial surveys).

Understanding that ZIP codes are well known (everybody has one and everybody knows theirs) and that it would be useful to present data on that level, the Bureau created “ZIP Code Tabulation Areas” (ZCTA) for the 2000 Census. They’re a collection of Census tracts that resemble a ZIP code’s area (they also often share the same 5-digit identifiers). The ZCTA and an area representing a ZIP code have a lot of overlap and can share much of the same space. ZCTA data is freely downloadable from the Census Bureau’s TIGER shapefiles website.

There’s a good discussion about what ZIP codes are and aren’t on the GIS StackExchange.

Chicago example of the problem

Here’s a real world example of the kinds of problems that ZIP code data availability and comprehension: Those working on the Chicago Health Atlas have run into this problem where they were using two different datasets: ZCTA from the Census Bureau and ZIP codes as prepared by the City of Chicago and published on their open data portal. Their solution, which is really a stopgap measure and needs further review not just by those involved in the app but by a diverse group of data experts, was to add a disclaimer that they use ZCTAs instead of the USPS’s ZIP code data.

ZIP-code related datasets

Fast forward to why I’m telling you all of this: The U.S. Department of Housing and Urban Development (HUD) has two ZIP-code based datasets that may prove useful to mappers and researchers.

1. ZIP code crosswalk files

This is a collection of eight datasets that link a level of Census geography to ZIP codes (and the reverse). The most useful to me is ZIP to Census tract. This dataset tells you in which ZIP code a Census tract lies (including if it spans multiple ZIP codes). HUD is using data from the USPS to create this.

The dataset is documented well on their website and updated quarterly, going back to 2010. The most recent file comes as a 12 MB Excel spreadsheet.

2. Vacant addresses

The USPS employs thousands of mail carriers to delivery things to the millions of households across the country, and they keep track of when the mail carrier cannot delivery something because no one lives in the apartment or house anymore. The address vacancy data tells you the following characteristics at the Census tract level:

  • total number of addresses the USPS knows about
  • number of addresses on urban routes to which the mail carrier hasn’t been able to delivery for 90 days and longer
  • “no-stat” addresses: undeliverable rural addresses, places under construction, urban addresses unlikely to be active

You must register to download the vacant addresses data and be a governmental entity or non-profit organization*, per the agreement** HUD has with USPS. Learn more and download the vacancy data which they update quarterly.

Tina Fassett Smith is a researcher at DePaul University’s Institute of Housing Studies and reviewed part of this blog post. She stresses to readers to ignore the “no-stat” addresses in the USPS’s vacancy dataset. She said that research by her and her colleagues at the IHS concluded this section of the data is unreliable. Tina also said that the methodology mail carriers use to identify vacant addresses and places under change (construction or demolition) isn’t made public and that mail carriers have an incentive to collect the data instead of being compensated normally. Tina further explained the issues with no-stat.

We have seen instances of a relationship between the number of P.O. boxes (i.e., the presence of a post office) and the number of no-stats in an area. This is one reason we took it off of the IHS Data Portal. We have not found it to be a useful data set for better understanding neighborhoods or housing markets.

The Institute of Housing Studies provides vacancy data on their portal for those who don’t want to bother with the HUD sign-up process to obtain it.

* It appears that HUD doesn’t verify your eligibility.

** This agreement also states that one can only use the vacancy data for the “stated purpose”: “measuring and forecasting neighborhood changes, assessing neighborhood needs, and measuring/assessing the various HUD programs in which Users are involved”.