Read enough SCA package titles and you start hearing the same four-beat phrase, over and over: roofs, exterior masonry, parapets, flood elimination. It's practically the agency's house rhythm.

So the As-Built desk counted, title by title, across more than 4,200 SCA solicitation records with bid dates from 2013 through 2026 — roof work shows up in 699 package titles. Exterior masonry, 619. Parapets, 591. Flood elimination, 333. Windows, 309. Put the envelope family together and nearly one in four packages on the board — 23 percent — names at least one of those scopes in its title.

“Water is the SCA's most reliable client. It files work orders every winter.”

No other family of work comes close. Boilers and climate control, for all the attention they get, total roughly 300 title appearances combined. Playgrounds, 290. Security cameras, 325. Here's the thing: at the SCA, the envelope isn't a market. It's the market. Everything else orbits it.

Why does the envelope rule? Because the buildings say so. New York City Public Schools operates roughly 1,400 facilities totaling about 130 million square feet, and a whole lot of it is early-twentieth-century brick. The same physics that gave the city facade laws for its high-rises — freeze-thaw, water, aging masonry — runs the SCA's repair cycle too. Facades, parapets, and roofs fail on a schedule, and the fix can't wait for a capital masterplan. Water is the SCA's most reliable client. It files work orders every winter.

Now, the bundling matters as much as the volume. The SCA almost never bids a roof by itself — the standard package welds roofs to parapets to exterior masonry to flood elimination, and often windows, into one lump-sum contract. What that means for you is simple: the winning bidder on envelope work is a firm that can self-perform or tightly manage three or four trades at once — not a roofer with a ladder. Roofing subs, masonry restoration crews, scaffold and hoist logistics, waterproofing — the package rewards the GC who has that bench built before bid day.

So if you're building a business plan around SCA work, the envelope is where the repeatable revenue lives. The packages come back every season, in every borough, at every size. It's also where the SCA's paperwork muscle memory runs deepest — scope templates, unit costs, and inspection routines are all well-worn. That cuts both ways: fewer surprises in the documents, less room to hide in the pricing.

Two quiet findings in the map deserve their own line. Accessibility and path-of-travel work — 349 packages — now outranks windows, boilers, and playgrounds. ADA scope has become a standing line in packages of every kind, and that's a specialty worth owning. And the fourth-biggest family on the board isn't a trade at all: 445 packages carry the Reso tag of City Council and borough president discretionary money. That one gets its own story later this week.

What this means for you: these counts come from more than 4,200 SCA solicitations posted since 2013, tracking how often each trade shows up in a package title. It's a map of the market's shape, not an audit of its dollars — a title can undersell what's actually in scope, and one package often names several trades at once. The takeaway for a business plan: envelope work (roofs, masonry, parapets, flood elimination) is the steadiest, most repeatable lane on the board, and the contractor who wins it self-performs or tightly manages three or four trades at once, not just one.

Next in the series: how rare a brand-new school actually is in the bid market — and why that's not bad news.