Sizing a submarket between CoStar refreshes

Anyone who's priced a submarket off a CoStar pull knows the number on the screen is already old by the time it posts. Under-construction figures update on a quarterly cycle, and a shed that topped out in month one of the quarter doesn't show as delivered until the refresh lands, sometimes weeks after it's already leasing space. If you're running comps or sizing competitive supply ahead of an acquisition, that lag sits right where you need precision most.

The lag comes from how the underlying data gets reported. Permit filings get entered late, brokers update listings on their own schedule, and completions get confirmed only after an occupancy certificate clears. Stack three or four of those delays together across a county and the "current" supply picture is really a picture of last quarter, dressed up as this one.

Why the lag matters more in tight submarkets

In a submarket with a handful of big-box sites under construction, missing even one or two completions skews your absorption math more than it would in a deep, liquid market with dozens of comparable deliveries. A single 600,000 square foot cross-dock coming online six weeks before your model says it should changes the vacancy rate you'd quote in an IC memo. If you're underwriting a deal where the thesis depends on constrained near-term supply, that's not a rounding error. That's the thesis.

The usual workaround is a manual trawl: permit portals by county, local news releases, broker chatter, maybe a call to a municipal planning office if you know who to ask. That trawl is slow and inconsistent across jurisdictions, and it only shows what's been filed. A permit can sit for a year before ground breaks, or get amended twice before the building looks anything like the original filing.

Reading the ground instead of the paperwork

The alternative is to look at what's physically there. A new slab, a tilt-up shell going vertical, a yard extension paving over what used to be a grass buffer, these show up in satellite imagery well before anyone files the paperwork that eventually makes it into a database refresh. Pull imagery at a regular cadence and you're not waiting on a filing clerk or a broker's update schedule. You're looking at the footprint itself.

That's the gap Warehouse Footprints sits in. It's a quarterly log of new large-format sheds and yard extensions in a region, pulled straight from high-res imagery (0.5 to 2 meter ground resolution, RGB) as a change layer. Instead of reconciling permit filings against news releases against broker updates, you get a direct read of what's actually gone up since the last pass, on a cadence that runs independent of anyone's reporting calendar.

It won't replace the full CoStar record. It's not pulling rent comps or lease terms, and it doesn't resolve down to signage or tenant identity. What it does do is put a floor under your supply count between refreshes: you can see a new shed's footprint exist before the filing confirms it, and size a yard extension before it shows up as an amendment three months later.

For pre-acquisition work specifically, that's the window that matters: whether the submarket you're underwriting picked up 400,000 square feet of competitive space this quarter that hasn't hit anyone's database yet. A quarterly supply estimate built off imagery doesn't carry the lag of a permit-and-press trawl, because it isn't waiting on anyone to file anything.

If you run comps in a county where ground has broken but the paperwork hasn't caught up, start on the Warehouse Footprints home page to see how the quarterly change layer is put together.