CategoryData

I’ve got property tax data for Chicago Cityscape

Wrigley Field Ahead of a Seemingless Meaningless Game, September 2011

Wrigley Field is an old baseball stadium in Chicago’s Lakeview neighborhood. Photo by Dan X. O’Neil

1. Licensed Chicago Contractors, my website that tracks what developers and the city are proposing to build or demolish in your neighborhood, is now called Chicago Cityscape.

2. I’m grateful to Ian Dees who helped me get property tax data for 2009-2013 for over 1.4 million PINs (property identification numbers) in Cook County.

I’m going through various parts of the property tax data and figuring out how to integrate it with Chicago Cityscape. The first time Ian got the data I found out I didn’t tell him to get the right PINs. I think I’ve fixed that now.

As part of this process I’m checking properties somewhat randomly, based on the permits I’m browsing. I most recently viewed a Wrigley Field building permit at 1060 W Addison Street – for a Zac Brown concert – so I searched its PIN and how much the property is “worth”. Here goes:

Year Amount Billed Assessed Value
2013 $1,517,665.09 $8,049,996
2012 1,498,971.03 8,049,996
2011 1,493,002.47 8,865,636
2010 1,489,160.89 8,865,636
2009 1,360,673.45 10,613,423

Notice how the assessed value dropped over $2 million from 2009 to 2010. And even though it had three unique assessed values, the annually changing tax rate adjusted the amount billed. You can see this information on the Cook County Property Info portal.

Finding teardowns in Chicago

1923 South Allport Avenue, built 1884

A recent suspected teardown, at 1923 S Allport in Pilsen (25th Ward, 19th place for teardowns from 2006 to now). The demolition permit was issued August 7 and the new construction permit was issued August 5. The new building will have an increase in density, with three dwelling units. Photo by Gabriel Michael.

From Wikipedia, a teardown is a “process in which a real estate company or individual buys an existing home and then demolishes and replaces it with a new one”.

You can find suspected* teardowns in the building permits data on Licensed Chicago Contractors by looking for demolition permits and new construction permits for the same address. I limited my search to situations where the demolition permit was issued within 60 days prior or subsequent to the new construction permit. This shows properties that have a quick turnaround (thus more likely to get built). I didn’t want to include buildings that may have been demolished one year and got a building two years later.

Analysis

This analysis is based on data since January 1, 2006, the start of the first complete year of building permits data in the Chicago open data portal, and ends today. The first demolition permit in this analysis was issued January 10, 2006, and its associated new construction permit was issued five days prior. There may be a case when the demolition permit and new construction permits were issued in different years, but for this analysis I only consider the year in which the demolition permit was issued. (In my review of permits since March I believe that new construction permits are issued most often after the demolition permit.)

Suspected teardowns

The number for teardowns decreased dramatically as the economic crisis approached.

Results

There were 1,717 suspected teardowns in Chicago distributed across 57 community areas (of 77, whose boundaries don’t change) and 45 wards (of 50, whose boundaries changed in 2012).

West Town, Lake View, and North Center share top billing, with the most teardowns each year, but Lake View was #1 for seven of 10 years. Other top five community areas comprise Logan Square (thrice), Lincoln Square (thrice), Bridgeport (twice), McKinley Park (once), and Near West Side (once).

From 2012 to current, the most teardowns occurred in Wards 32 (Waguespack), 47 (Pawar), 1 (Moreno), 44 (Tunney), and 43 (Smith). All of those wards include parts of the top three community areas mentioned above.

The sixth ward with the most teardowns in this period was 2 (Fioretti) but this boundary no longer represents any part of the pre-2012 boundary that covered almost the entire South Loop. That means Ward 2 is now covering the west side. Additionally, the 2nd Ward made sixth place with 28 teardowns and fifth place, the 43rd Ward had 60 teardowns.

The South Loop, represented by the Near South Side community area, has had 0 suspected teardowns from 2012 to now. There was one teardown in the entire time period, where a three-story commercial was demolished at 1720 S Michigan Ave and replaced with a 32-story residential tower.

What else do you want to know about teardowns in Chicago?

* Notes

I use “suspected” because it’s impossible to know from the data if buildings were actually demolished and constructed.

Download the data as CSV for yourself.

Morgan CTA station ranks highly in rail system for building permits

Let Your Conscious Be Your Guide

The gutted cold storage warehouse in the background is within a quarter mile of the Morgan CTA station. Photo by Seth Anderson.

Excluding all of the Chicago Transit Authority stations in the central business district you’ll find that the new Morgan station ranks highly in the number of building permits issued within a quarter mile. It has a top spot when you calculate those permits’ estimated project costs. The CTA recently discussed with DNAInfo the results of a preliminary study it conducted that showed how the Morgan station is at the center of a lot of construction growth in the West Loop/Fulton Market area, and a contributing factor to this growth.

Now that Licensed Chicago Contractors shows you the two nearest CTA and Metra rail stations to each building permit, and I’ve become well-versed in writing PostGIS queries on the fly, I wrote a query that lists the CTA stations with the most building permits within a quarter mile (“nearby”).

First, though, let’s count how many stations don’t have permits nearby. With the query at the bottom you get a list of station names, the number of permits nearby, and a sum of the estimated costs of those permits sorted by the number of permits. Since I used a “LEFT JOIN” I also get a count of all the permits (the table on the LEFT) that don’t have a match with CTA stations (the table on the right).

There are 127 rows returned and a previous count of the table told me there are 145 stations, including ones outside the Chicago city limits. (There are stations in Cicero, Wilmette, Evanston, Rosemont, Oak Park, Forest Park, and Skokie.) The first row represents NULL, or all of the stations that don’t have permits nearby. That leaves me with 126 rows and 19 stations without permits, or 19 stations outside the City of Chicago.

I verified this by eyeballing it. I looked at a map and counted roughly 19 stations that wouldn’t have the 1/4 mile overlap with a Chicago building permit. The two Austin stations, on the Blue Line Forest Park branch and the Green Line Oak Park branch, are near Chicago and also showed up as a discrete station in the query results. Austin on the Blue Line was dead last, actually!

Let’s get back on track and look at Morgan now. I don’t think it’s fair to compare the Morgan station area with an expected, higher-activity area like the Loop and Central Business District so I eyeballed the list and started the #1 ranking with the first station outside the CBD.

  1. Armitage (Brown, Purple Express) is the station outside the CBD with the most building permits nearby.
  2. Damen-Milwaukee (Blue)
  3. North/Clybourn (Red)
  4. Addison (Red)
  5. Morgan (Green, Pink)

There you have it, from 2009 to today, the Morgan station had the fifth highest number of building permits outside of the Chicago Central Business District. It beat Fullerton (Red, Brown, Purple) in Lincoln Park, and Roosevelt (elevated and subway combined) in the South Loop. The station’s construction began in 2010 and the grand opening occurred May 24, 2012. During this period Morgan had the second highest amount of aggregated estimated costs at $199,911,953.00, behind North/Clybourn, at $218,118,037.37.

Take this analysis with several grains of Morton salt, though, because the following caveats are important to consider: building permits are really speculative development; much of these may be for kitchen renovations or porch reconstructions; I didn’t look up when it was “for sure” that the station was being built so I don’t know when developers would have become interested.

Looking at a longer period

I will, however, run a few more queries to find how Morgan’s position changes, starting with expanding the query to “all time” data (really the end of 2006 to today). It turns out that when looking through all available years Morgan’s position remains at #5 but other stations change position.

  1. Fullerton
  2. Armitage
  3. Damen-Milwaukee
  4. Addison
  5. Morgan

During this period, which covers the end of 2006 until today, Morgan had the highest aggregated estimated costs of the above five stations, at $236,707,083.00. It beat Fullerton’s amount of $160,825,680.30.

Looking only at “new construction”

Since these include all permit types, including water heater installations and window replacements, it doesn’t give us a good look at economic expansion in the areas surrounding CTA stations. I’ve filtered the data so only “new construction” building permits come through. I’m still interested in stations outside the CBD. Here’s how Morgan performed when looking at purely the quantity of new construction permits issued from 2009 to today:

  1. Armitage, 46 new construction building permits
  2. Southport, 38
  3. Addison (Red), 34
  4. North/Clybourn,
  5. Wellington,
  6. California-Milwaukee,
  7. Belmont (Red)
  8. Ashland (Green, Pink)
  9. Irving Park (Brown)
  10. Fullerton
  11. Damen (Brown)
  12. Division-Milwaukee
  13. Western-Milwaukee
  14. Ashland (Orange)
  15. Damen-Milwaukee
  16. Western-Congress
  17. Paulina
  18. Addison (Brown)
  19. Diversey
  20. Sedgwick
  21. Loyola
  22. Montrose (Brown)
  23. Sox-35th-Dan Ryan
  24. Morgan, 13 new construction building permits

Let’s remove that date filter and look at the whole building permits period of late 2006 to today.

  1. Southport (Brown Line), 80 new construction permits, all-time
  2. Armitage (Brown, Purple), 72
  3. Western-Congress (Blue), 66
  4. Addison (Red), 64
  5. Belmont (Red, Brown), 63
  6. Western-Milwaukee, 59
    Damen-Milwaukee, 59
  7. North/Clybourn, 55
    Diversey, 55
  8. Division-Milwaukee, 53
  9. Sox-35th-Dan Ryan, 51
  10. Wellington, 50
  11. 35-Bronzeville-IIT, 48
  12. Irving Park (Brown), 44
  13. Morgan, 43 new construction permits

Now switching the order method around and Morgan appears better when you look at aggregated estimated costs, from 2009 to today.

  1. Illinois Medical District, $236,020,000.00
  2. North/Clybourn, $172,373,335.00
  3. Loyola, $161,744,075.00
  4. Polk, $106,000,000.00
  5. Grand-Milwaukee, $77m224,500.00
  6. Wellington, $72m802,300.00
  7. Belmont (Red), $71,300,302.00
  8. Morgan, $68,300,800.00

Last query – remove the data filter and look at aggregated costs for the whole building permits period where Morgan maintains a top 10 position.

  1. North/Clybourn, $277029045.00
  2. Illinois Medical District, 236,020,000.00 (same as 2009 to today period)
  3. Polk, $188,794,975.00
  4. Loyola, $185,444,075.00
  5. Belmont (Red), $1635,00,085.00
  6. Fullerton, $129,444,051.00
  7. Wellington, $111,335,051.00
  8. Granville, $99,356,702.00
  9. Morgan, $83,995,800.00

The data I’d really like to have, though, is sales tax receipts for the same years.

This is not a valid PostgreSQL query. The brackets indicate the options I was using to retrieve the above results. The geometries are in or transformed to EPSG 3435 (Illinois StatePlane East Feet) and 1,320 feet is a quarter mile.

SELECT
 COUNT (P .permit_) AS count,
 MIN (C .longname) as name,
 min(lines) as lines, 
 sum(_estimated_cost) as sum
FROM
 permits P left join
 stations_cta C
ON
 ST_DWithin (
  ST_Transform (P .geometry, 3435),
  C .geom,
  1320
 )
[WHERE] [EXTRACT (YEAR FROM issue_date) >= 2009] [_permit_type = 'PERMIT - NEW CONSTRUCTION']
GROUP BY
 C .gid
ORDER BY
 [count,sum] DESC

Playing around with Chicago data: who’s running red lights?

Range Rover with Illinois license plate "0"

A Range Rover with Illinois license plate “0” is seen moving 40 MPH in a 30 MPH zone through a red light at Ashland and Cortland.

I’m just seeing who’s driving around Chicago one night, using the Tribune-published dataset of over 4.1 million tickets issued from red light cameras.

The City of Chicago has installed at least 340 red light cameras since the mid-2000s to reduce the number of people running red lights and crashing. They’re supposed to be installed at intersections where there’s a higher-than-average rate of right angle (“T-bone”) crashes, which are more injurious than other typical intersection crash types.

Assessing safety wasn’t the Tribune’s story angle, though. It was about showing spikes in the number of tickets issued, which I verified to some extent. The article called the tickets issued during these spikes “undeserved” and “unfair”. The data doesn’t have enough information to say whether or not that is the case; a video or extensive photo review is necessary to rule out rolling right turns while the light was red (a much less dangerous maneuver unless people are trying to cross the street).

The first query I ran assessed the number of people who get more than one ticket from a red light camera. Since I was tired my query was a little sloppy and it missed a lot of more useful order choices and didn’t select the right fields. I fell asleep and started again in the morning. This time, I got it right in just two tries – I needed to try again because I mistakenly put HAVING before the GROUP BY clause.

Here’s the first query, in its final form, to retrieve the number of tickets for each license plate in each state (I assumed there may be identical license plates among states).

select max(ticket_number), max(timestamp), license_plate, state, count(*) AS count FROM rlc_tickets group by license_plate, state HAVING count(*) > 1 order by count DESC NULLS LAST

It resulted in 851,538 rows, with each row representing a unique license plate-state combination and the number of red light violations that combination received. You can reasonably assert that cars don’t change license plates more than a couple times in a single person’s ownership, meaning you can also assert that each row represents one automobile.

851,538 vehicles, which make up 35.1% of all violators, have received 2,601,608, or 62.3%, of the 4,174,770 tickets. (There are 2,424,700 license plate-state combinations, using the query below.)

select count(ticket_number) from rlc_tickets group by license_plate, state

Here’re the top 10 vehicles that have received the most violations:

  1. SCHLARS, IL, 78
  2. 9720428, IL, 59
  3. 8919589, IL, 57
  4. A633520, IL, 52
  5. 3252TX, IL, 45
  6. A209445, IL, 44
  7. N339079, IL, 44
  8. X870991, IL, 41
  9. 239099, IL, 41
  10. 4552985, IL, 40

The next step would be to design a chart to show these vehicles’ activity over the months – did the vehicles’ drivers’ behavior change, decreasing the number of red light violations they received? Did the vehicle owner, perhaps a parent, tell their child to stop running red lights? Or has the vehicle owner appealed erroneously-issued tickets?

When I ran one of the first, mistaken, queries, I got results that put license plate “0” at the top of the list, with only nine tickets (license plates with two or more zeros were listed next).

I googled “license plate 0” and found a 2009 Tribune article which interviewed the Range Rover-driving owner of license plate “0” and the problems he encountered because of it. The City of Chicago parking meter enforcement staff were testing new equipment and used “0” as a test license plate not knowing such that license plate exists. Tom Feddor received real tickets, though.

I then looked up on PhotoNotice the license plate and ticket violation number to find, indeed, the license plate belonged to someone driving a Range Rover at Ashland Avenue and Cortland Street on July 17, 2008. An added bonus was Feddor’s speed in that Range Rover: the camera recorded the car going 40 MPH in a 30 MPH zone.

I was done browsing around for the biggest offenders so next I wondered how many tickets were issued to vehicles licensed in Arizona, where U-Haul registers all of its nationwide vehicles. Arizona plates came in 29th place for the greatest number of tickets.

select count(*) AS count, state from rlc_tickets group by state order by count DESC NULLS LAST

As you may have expected, four surrounding Midwest states, and Ohio, rounded up the top five states after Illinois – but this isn’t notable because most visitors come from there and they each only comprise less than 1.3% of the total tickets. The next state was Florida.

  • 3,986,739, IL
  • 51,104, WI
  • 40,737, MI
  • 27,539, IN
  • 8,550, OH
  • 7,684, MN
  • 7,139, FL

What’s next: I’m working on finding a correlation between the number of reported crashes, and type, at intersections with red light cameras and the number of tickets they issued. I started doing that before running the numbers behind this blog post but it got complicated and it takes a long time to geospatially compare over 500,000 crash reports with over 4.1 million red light tickets.

What else do you want to know?

I will delete all comments that don’t discuss the content of this post, including comments that call red light cameras, or this program, a “money grab”.

Red light camera ticket data insufficient to find cause for spikes

Spike in tickets issued at 119th/Halsted in May and June 2011. Nodes represent tickets grouped by week.

Spike in tickets issued at 119th/Halsted in May and June 2011. Nodes represent tickets grouped by week.

The Chicago Tribune published a dataset of over 4 million tickets issued to motorists for entering an intersection after the light had turned red. They analyzed the dataset and found unexplained spikes, where the number of tickets, being issued by the handfuls each day, suddenly tripled. (Download the dataset.)

I looked at the tickets issued by two of the 340 cameras. I didn’t find any spikes at Belmont/Sheridan (“400 W BELMONT”) but found a noticeable spike in May and June 2011 at the 119th Street and Halsted Street intersection (“11900 S HALSTED”).

I looked at three violations on one of the days that had an atypical number of tickets issued, May 12, 2011. Each motorist was ticketed, it appears, for turning right on red. It’s not possible, though, without watching the video, to see if the motorist rolled through the turn or indeed stopped before turning right.

The Tribune called tickets issued during these “spikes” “undeserved” but that’s hard to say without see the violations on video. The photos don’t provide enough evidence. The Tribune also reported that appeals during these spike periods were more likely to be overturned than in the period outside the spikes. The reporters discussed the possibility of malfunctions and malicious behavior, calling that an “intervention”.

The Chicago Department of Transportation, which oversees the program formerly operated by Redflex and now operated by Xerox, couldn’t refute either allegation, possibly with “service records, maintenance reports, email traffic, memos or anything else”. David Kidwell and Alex Richards report:

City transportation officials said neither the city nor Redflex made any changes to how violations were enforced. They acknowledged oversight failures and said the explosions of tickets should have been detected and resolved as they occurred. But they said that doesn’t mean the drivers weren’t breaking the law, and they defended the red light camera program overall as a safety success story. The program has generated nearly $500 million in revenue since it began in 2003.

The city was unaware of the spikes until given the evidence by the Tribune in January, said David Zavattero, a deputy director for the Chicago Department of Transportation. In the six months since, city officials have not provided any explanations.

“Trust me when I tell you that we want to know what caused these spikes you have identified as much as you do,” Zavattero said. “So far we can find no smoking gun.”

He acknowledged that faulty camera equipment likely played a role.

“I would say that is likely in some of these cases,” Zavattero said. “I cannot tell you that isn’t possible. It is possible. The old equipment was much more prone to break down than the equipment we are currently installing.”

You can download the data but you will likely produce the same results as the Tribune, but maybe a different conclusion. Their analysis has led people at all levels of the civic sphere to call for an investigation, including citizens, some of whom have filed a lawsuit, Alderman Waguespack and 19 other aldermen, and CDOT commissioner – who operates the red light camera program – Rebekah Scheinfeld.

I think they sufficiently identified a suspicious pattern. By the end of the long story, though, the Tribune didn’t prove its hypothesis that the tickets were “undeserved” or “unfair”.

In violation number 7003374335 you can see the driver of a Hyundai Santa Fe turning right at a red light. The Google Street View for this intersection shows that there is no RTOR restriction, meaning the driver is legally allowed to make a right turn here with a red light after coming to a complete stop and yielding to people in the crosswalk. But we can’t see if they stopped first. The next two violations that day at the same intersection I looked showed the same situation. (Find the violation by going to PhotoNotice and inputting 7003374335, NWD648, and CHI.)

I look forward to the investigation. The Tribune made a great start by analyzing the data and spurring the call for an investigation and it seems there’s not enough information in this dataset to explain why there are more tickets being issued.

One dataset that could help provide context – because these spikes, at least the ones that are sustained, don’t seem random – is knowing the number of vehicles passing through that intersection. The speed camera data has this information and allows one to show how different weekend traffic is from weekday traffic.

The "before" image showing the Santa Fe vehicle approaching the stop bar.

The “before” image showing the Santa Fe vehicle approaching the stop bar.

Violation photo 2

After: The Santa Fe vehicle is seen in a right turn.

Note: The Tribune identified 380 cameras but running a DISTINCT() query on the “camera name” field results in 340 values. Some cameras may have identical names because they’re at the same intersection, but you can’t discern that distinction from the dataset.

Morgan CTA station is fueling new West Loop development

First day of CTA Morgan Station serving the Green and Pink Lines

The Morgan Station was designed by Ross Barney Architects.

DNA Info Chicago discusses an informal study the Chicago Transit Authority conducted that showed, “since the [Morgan Green/Pink Line] station opened in May 2012, residential and business development in the surrounding neighborhood has continued at a faster pace than nearly all other markets within the city during the post-recession period.”

Morgan connects two major restaurant rows, one on Randolph Street that stretches much further east at Jefferson all the way west to Racine, and another on Fulton Market that starts at Carnavale (next to the Kennedy Expressway) and stretches to Morgan. Google’s huge new headquarters (under construction) and Coyne College – an HVAC institute – are within walking distance.

Using ridership information and commercial rents data, as well as information from the Chicago open data portal, CTA spokesperson Catherine Hosinski listed the following findings in the study:

  1. “A more than 20 percent increase in new business licenses.”
  2. “New construction and demolition permits spiked from one to 15. (The new construction/demolition permits issued after the opening of the station were compared to a 21-month period during the construction from August 2010 through May 2012)”
  3. “Average weekday ridership increased 30 percent between May 2013 and May 2014, according to information reflecting a 12-month rolling average over a 36-month period.”
  4. “Average weekend ridership increased more than 20 percent.”

Item #2 is data that we can see on Licensed Chicago Contractors. To help CTA planners and residents see this information more readily I’ve added all 145 CTA stations as places you can explore from the Places page.

How can you use this new place in connection with CTA’s study? With it you’ll be able to easily see building permits issued within half a mile from the CTA station and download this data for the last 9 years. You can also sort by projects’ estimated costs to find the biggest investments near the station.

Hosinski admits an important part of the study when she told DNA Info, “the West Loop was showing signs of becoming a booming neighborhood before the station was built…its presence has contributed to the migration of commuters and residents to the area.” Hosinski also said that you’ll find CTA stations at the heart of “most” Chicago neighborhoods and now CTA stations are part of the heart of tracking building permits.

Here’s how to track building permits (including demolitions and new construction) around any CTA station:

  1. Open the Places page on Chicago Cityscape
  2. Search for a station name (like Morgan), route name, or click “CTA Rail Station” in the right sidebar.
  3. Done! The list is sorted by the permit’s issue date, but click on any of the table headers to sort differently.
Morgan station on Licensed Chicago Contractors

We’re tracking over 1,700 building permits within a half mile of the Morgan station since July 2005.

Chicago wards with the most landmarked places

Montgomery Ward Complex

People float by the Montgomery Ward Complex on Kayaks. Photo by Michelle Anderson.

Last week I met with the passionate staff at Landmarks Illinois to talk about Licensed Chicago Contractors. I wanted to understand the legality for historic preservation and determine ways to highlight landmarked structures on the website and track any modifications or demolitions to them.

I incorporated two new geographies over the weekend: Chicago landmark districts, and properties and areas on the National Register of Historic Places (both available on the City of Chicago open data portal).

I used pgShapeLoader to import them to my DigitalOcean-hosted PostgreSQL database and modified some existing code to start looking at these two new datasets. Voila, you can now track what’s going on in the Montgomery Ward Company Complex – currently occupied by “600 W” (at 600 W Chicago Avenue) hosting Groupon among other businesses and restaurants.

Today I was messing around with some queries after I saw that the ward containing this place on the National Register – the 27th – also had a bunch of other listed spots.

I wrote a query to see which wards have the most places on the National Register. The table below lists the top three wards, with links to their page on Licensed Chicago Contractors. You’ll find that many have no building permits associated with them. This is because of two reasons: the listing’s small geography to look within for permits may not include the geography of issued permits (they’re a few feet off); we don’t have a copy of all permits yet.

[table id=15 /]

4 wards don’t have any listings on the National Register of Historic Places and nine wards have one listing.

Building permits for new and changed things in 2014 is going up

New City 19-story residential tower under construction near Lincoln Park.

The building permits data that powers Licensed Chicago Contractors has 11 permit types and I analyzed five of them to show the “new stuff” activity in Chicago this year through May 26, 2014. “New stuff” is the economic indicator to show that things are getting built. It includes the permits issued for new construction, renovation and alteration, porches, easy permit process (which can include things like kitchen renovation, or a new garage), and electric wiring where the estimated project cost is greater than $1.

You can see there was a small dip between January and February but since then has been climbing. See How’s Business? for more business-based metrics of the Chicago economy.

After publishing this chart I decided I’ll include signs because that is part of the “new stuff” activity I am trying to visualize. The other five permits are for scaffolding (a job indicator but not a “new stuff” indicator), elevator equipment (these aren’t always about new or replacement projects), wrecking and demolition (these permits usually don’t include estimated costs), and permits that represent extensions and reinstatements.

Top 20 most active general contractors in Chicago this year so far

River Point tower is under construction at 444 W Lake Street by James McHugh Construction. Its associated building permit, which only comprises the base/train cover structure depicted, has an estimated project cost of $27,050,000. Photo by Bart Shore.

Here I go again not talking about urban planning on Steven Can Plan. With my Licensed Chicago Contractors & Construction Activity website I’ve ingested a lot of data from the City of Chicago’s open data portal that has a LOT to say about what’s going on.

Nearly all permits include a reasonable value that estimates the project’s cost – like $13,150,000.00 for converting Lafayette Elementary School into a performing arts high school. (All demolition permits show $1 and some permits cost over $6 billion, which we know is false.)

I recently reorganized the data (migrating from MySQL to PostgreSQL which supports the JSON datatype) to expand the ways I can extract info and I’ve sorted it by general contractor’s aggregate project value for this year.

This is a list of the 20 most active general contractors in Chicago for 2014 until May 13, 2014. I define “activity” purely by the companies’ involvement in a Chicago-based project and corresponds to that project’s estimated cost. (The data doesn’t specify a level of their involvement in a project.)

[table id=11 /]

Do any names ring a bell, or surprise you?

Finding interesting data in the building permits dataset

I had several great conversations with fellow #chihacknight visitors at the 1871 tech hub (222 W Merchandise Mart Plaza) about how to reveal more information about what’s being built in Chicago. I had introduced Licensed Chicago Contractors at the previous week’s hack night and tonight I showed site changes I made like how much faster it is now that I use DataTables’s server-side processing function.

Some of the discussions resulted in suggestions to try new tools and methods that would make processing the data more efficient, or more revealing. What are the ways I can aggregate the data, or connect to similar data from other sources?

One of the new features I announced I’ll be adding is statistics on building activity by neighborhood. I started testing some queries to see the results, and to find the query that outputs that information in a way that’ll pique users’ interests.

I calculated the aggregate estimated costs of all building permit activity for the past 90 days in select neighborhoods. All of the data was automatically generated using a simple MySQL query, but one that will get faster after switching to Postgres. (I eliminated any project whose estimated cost was less than $1,000 because there are many project types that are $0 to several hundred dollars.)

  • Logan Square: 77 projects, totaling $16,295,997.50 at a $211,636.33 average cost
  • West Loop: 30 projects, totaling $27,646,899.00 at a $921,563.30 average cost
  • Andersonville: 6 projects, totaling $358,770.00 at a $59,795.00 average cost
  • Bronzeville: 34 projects, totaling $17,050,662.00 at a $501,490.06 average cost
  • Hyde Park: 20 projects, totaling $13,492,265.00 at a $674,613.25 average cost
  • Humboldt Park: 35 projects, totaling $41,917,988.00 at a $1,197,656.80 average cost

How does Humboldt Park double the other neighborhoods’ average? I think it’s pretty simple: this $40 million Salvation Army residence that’s going to be built at 825 N Christiana Avenue.

The results for Bronzeville were higher than I expected because this is a distressed neighborhood that has lost of lot of population and has seen little development in the past several years. This isn’t to say the neighborhood is poor – I saw a report last fall that highlighted how the purchasing power of Bronzeville residents was quite high relative to neighboring communities.

Ronnie Harris showed me the report when I participated in the Center for Neighborhood Technology’s civic app competition and hackathon. We, along with Josh Engel, designed Build It! Bronzeville, although my participation was really pushing them to develop Josh’s game idea more and construct a paper version of it. Our team won the competition and Ronnie and Josh have kept working on it (I saw them at last week’s hack night).

Projects that pushed up Bronzeville’s average included several multi-family homes at around $1.4 million each on the blocks of 4700 and 4800 S Calumet Avenue.

Code discussion

I can’t test for the “Loop” right now in the way I have my data structured because a LIKE ‘%loop%’ query of the database will include “West Loop” records.

I need to change how the building permit data is stored – in my database – a little so that my site’s PHP codebase and MySQL queries can sift through the data faster. For example, I’m storing several key-value pairs as a JSON-encoded string in a TEXT field. One #chihacknight developer suggested I switch from MySQL to PostgreSQL because Postgres has native JSON-parsing functions.

I looked up how to use Postgres’s JSON functions and realized that, yes, I probably should do that, but that I also need to change the array structure of the data I’m encoding to JSON. In other words, with a tiny change now, I can be better prepared for the eventual migration to Postgres.

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