A City Page, Not an Atlas

A four-acre tract in Fort Worth, zoned D, the city’s highest-density apartment district. The street is in front. Somebody’s backyard is behind. Do you draw three stories or four? The D row in the zoning record looks like it answers that: 36 feet, or 48. It doesn’t. The answer is in the notes under the row, and part of it isn’t in the record at all.

This is the page the zoning wiki was supposed to be. Not the atlas, not a state map: one city, one row, read all the way down. I picked Fort Worth because its record is thin in an honest way. The profile in this repo holds 34 base districts and 7 overlays, with 78 values confirmed from the code, 24 inferred and 36 partial. Most commercial rows are a height and nothing else. D is one of the rows the researchers read from the section text itself, §4.712, so it’s about as good as this record gets. The city name is not the entitlement. The row is, and the notes under it.

What the row holds

D stores 32 units an acre. Lot coverage is 65%, which the record gets by subtracting a 35% open-space minimum from the whole lot. Setbacks are 20 feet front, 5 side and 5 rear. Lot width is 50 feet. Parking is one space per bedroom, plus, per the record’s definitions, one per 250 square feet of common area. Height comes in two values: 36 feet within 250 feet of a one- or two-family district, 48 feet beyond. Two cells are empty: floor-area ratio and minimum lot area. A missing maximum stays unknown. It isn’t zero and it isn’t unlimited.

Now the tract. It’s my example, not a real parcel: 330 feet of frontage by 528 feet deep, 174,240 square feet, exactly four acres. A-5 houses sit behind it (the record calls A-5 the smallest standard A-series one-family district, common in the inner-loop neighborhoods). Nothing residential is on either side. 32 × 4 = 128 apartments. That number doesn’t move for the rest of this page.

The rear setback is not five feet

The rear cell says 5 feet. The note on the side setback, and a rule spelled out further down the file, say something else. Where a CR, C or D building adjoins a one- or two-family district, it sets back 3 feet for every foot of height or 2 feet for every foot to the roof peak, whichever is greater, and never less than 30 feet. A 36-foot building sits 3 × 36 = 108 feet from the houses. Read the cell without the note and you’d draw the building 103 feet too close. The record says it plainly: Fort Worth’s apartment heights are “constrained more by this buffer than by the 36/48 ft base height.”

Then the 250-foot line. Forty-eight feet is allowed only beyond 250 feet from the houses. On a 528-foot-deep tract that’s the first 278 feet from the street, less the 20-foot front setback: a band 258 feet deep across the 320 feet left between the side setbacks, 82,560 square feet. Behind it, 142 feet at 36 feet, 45,440 square feet. Behind that, 108 feet of no building at all.

Three floors or four

My planning numbers, not the record’s: 1,000 gross square feet per apartment including corridors and stairs, 1.5 bedrooms on average, 12-foot floors (the record’s own stories-to-feet conversion), and 350 square feet per surface parking space with its share of drive aisle.

128 × 1,000 = 128,000 square feet. On three floors that’s a 42,667-square-foot footprint. On four floors, all inside the front band, it’s 32,000. The fourth floor adds zero apartments. Density capped the count at 128 before height had a say. What the fourth floor buys is ground: 10,667 square feet, about a quarter acre.

Does a quarter acre matter? Count the parking. 128 apartments × 1.5 bedrooms = 192 spaces, and 192 × 350 = 67,200 square feet of paving. Building plus paving is 109,867 square feet on three floors, 63% of the lot, and 99,200 on four, 57%. The line is 65%: 113,256 square feet. If paving counts against open space, and I’d assume it does until the city says otherwise, three floors leave 3,389 square feet of slack. Every 250 square feet of clubhouse adds a space, so a square foot of one-story clubhouse costs 2.4 square feet of ground. Three floors leave room for a clubhouse of about 1,400 square feet. Four leave room for about 5,900. That’s what the fourth floor is for.

What the control shows

The control below holds the tract and the 128 apartments fixed and steps down the record: the row, the buffer note, the 250-foot line, three floors, four floors, then the empty cells. The strip across the top is the stored D row; the highlighted cells are the ones in play, and the dashed cells with question marks are empty. The section under it is at true scale, street on the left, houses on the right. The bars are the footprint spread across the buildable width as two buildings. They are not a site plan. Watch the first card and the last one. The apartment count never moves. Only the ground does.

Where the record runs out

Empty cells are questions, and so are some of the filled ones. Here’s what I’d ask Fort Worth before I trusted this tract.

Floor area and lot area. Both cells are blank on D. The record’s definitions say floor-area ratio isn’t Fort Worth’s primary intensity measure, which explains the blank without answering it.

Open space. The 65% is the record’s arithmetic, not a stored limit. Whether a parking lot counts as open space is the difference between a three-story scheme with a clubhouse and one without.

Height, measured three ways. The D note measures height slab to top plate. The buffer formula uses slab to sill plate. The definitions say grade to the highest point. The 108 feet depends on which one the city means.

The bufferyard. The same buffer rule adds a 5-foot bufferyard and a 6-foot screen fence, scored on a point system the record names and doesn’t hold.

SB 840. The D note says the state law may allow 36 units an acre where D sits next to commercial or mixed-use land. The SB 840 entry in the same file, and the Texas state record, list commercial, office, retail, warehouse and mixed-use zones. D is an apartment district. Two sentences in one file disagree, and I’d plan on 32.

Overlays. The city page carries seven, including the air installation zone around NAS JRB Fort Worth, where the record says homes are prohibited in the clear zone and both accident-potential zones. Whether one covers this tract is a map question, not a row question.

The date. The profile was researched April 26, 2026, but the code host blocked scripted requests, so the confirmed tables came from archived copies of the section pages. The latest supplement the record could read was captured June 13, 2024. Anything Fort Worth amended since isn’t here, and the record flags its own dates as missing. These saved values are a screening scenario. Check them against the parcel, the overlays and the current code before a purchase decision.

My judgment: on a Fort Worth D tract that backs onto houses, the fourth floor is a parking decision, not a density decision. Draw it only where you need the ground, and draw the building 108 feet off the back fence, not 5. A city page is worth having only if you read it all the way down: the cell, the note under the cell, and the question where a cell is blank.

That is the end of the zoning evidence: the cell, the note under it, the date and the edition. The record holds more than zoning, though, and the remaining Atlas explorations each read one of those other layers against a single site.