Price the Rule at the Application Date
A parcel’s development option can change between acquisition and application. A law’s effective date, its transitional provisions and the project’s qualifying date belong in the underwriting.
Here is the case I’d actually lose sleep over. You have two acres under contract in Arlington, Texas, zoned General Commercial (GC), and you want to build apartments. It’s my example, not a real parcel, but every limit and date below comes from the Arlington profile in this corpus. The dirt doesn’t change in this story. The date on your application does.
Six days in August
Texas’s SB 840 took effect September 1, 2025; its new-development provisions apply to projects initiated on or after that date. Arlington didn’t wait. The profile records Ord. 25-059, adopted August 26, 2025, which moved GC up to the SB 840 numbers six days early.
Before. The profile’s note for GC gives a pre-SB 840 limit of 40 ft and 22 units an acre. On two acres that’s 2 × 22 = 44 units, at best. The same profile adds that a pure apartment building needed either the SB 840 pathway or RMU/NMU zoning, so 44 was a ceiling with a zoning case in front of it, not a permit.
After. The city can’t hold GC below 36 units an acre or 45 ft, can’t require setbacks over 25 ft and can’t require more than one parking space per unit. 2 × 36 = 72 units, by right, no rezoning. Same dirt, 28 more apartments, about 64% more.
Now price it. Borrow the placeholder the Same Dollar page uses, $1 million an acre, so $2 million for the pad. Spread over 44 units that’s $45,455 of land per apartment. Over 72 it’s $27,778. I’d bet the seller’s broker has read SB 840 too and priced the land at 72. If your application lands on the wrong side of September 1, you paid for 28 apartments you can’t build without a zoning case.
Texas isn’t special. California’s AB 2011 began July 1, 2023 and has since been amended. An older summary can describe a bargain different from the one available to a new application.
How to read the control
The applet below holds the pad still and moves only the filing date: August 25, August 29 and September 2, 2025. Those three dates are mine, picked to land before the city vote, between the vote and the state date, and after both. The two blue dates on the timeline are the recorded ones.
Fixed on every date: two acres, GC zoning, the $1 million-an-acre placeholder, and a city of 394,266 in a county of 2,140,629, both over SB 840’s 150,000 and 300,000 thresholds by the profile’s 2024 Census figures. What moves: density, height, the unit count and land per apartment. Watch the middle date. That’s the one that should scare you.
Use the timeline below to find a possible trigger, then read the operative law. A historical event is not evidence that its original rule still applies. The useful output is the rule your proposal can invoke, the conditions it must satisfy and the date those conditions are tested.
Where the record stops
The middle date is unsettled because the record runs out. It dates Ord. 25-059’s adoption, not its effective date. It doesn’t say what “initiated” means for a project: the purchase, a pre-application meeting, the first filing, the permit. And there is no vesting record anywhere in this corpus, which the Zoning Time Machine already admitted. Ask the city, then your lawyer.
The bigger gap is the number itself. The state record in this corpus, checked against the enacted text, says a city can’t set density below the greater of 36 units an acre or the highest residential density it allows. The Arlington profile stores 36 for GC. The same profile lists Regional Mixed Use (RMU) at up to 100 units an acre. If that 100 counts, the floor on this pad isn’t 72 units, it’s 200. I don’t know which reading the city applies, and neither does the record. That’s a 128-unit question.
The date isn’t the only test, either. The same state record excludes heavy-industrial zones, sites within 1,000 feet of heavy industry or 3,000 feet of an airport or military base, and mixed-use buildings with less than 65% residential floor area. Check the site before you check the calendar.
My judgment: on a commercial pad in a big Texas city, the application date is a term of the deal, not paperwork. Write the rule your filing can invoke next to the land price, with the date that rule is tested, and don’t let the earnest money go hard until you know which side of that date you’re on. Thesis 67 says to pin a project’s building code like a software dependency. This is the same discipline for zoning.