How do I understand an engineering sheet from a discipline I don't know?

The problem: every sheet assumes you speak its discipline

Plan sets are written for specialists. The mechanical sheets assume you know what a VAV box does. The electrical sheets assume a riser diagram means something to you. The plumbing riser assumes you can tell sanitary from storm at a glance. That's fine until you're the PM, the owner's rep, the new hire, or the structural reviewer who has to look at everyone else's sheets too.

Engineering Mode exists for exactly that gap: not to make you an MEP engineer, but to make the sheet legible while you're looking at it.

What it shows you, in two layers

First, the discipline profile. The mode reads the sheet's own text — the sheet number in the title block and the title keywords — and classifies it against the standard conventions: S sheets are structural, A architectural, M mechanical, E electrical, P plumbing, C civil, FP fire protection, L landscape, G general/cover. The sidebar then shows what that discipline answers — mechanical is "how does air get around?", plumbing is "how do pipes flow?", structural is "what holds this up?" — plus what to expect elsewhere in the set for that discipline (duct plans, riser diagrams, panel schedules, and so on).

Second, the elements. The mode drops temporary callouts directly onto the drawing — each one an arrowhead landed on an element with a short plain-language explanation: "Sanitary sewer — carries waste water from fixtures to the sewer main." "VAV box — terminal unit metering air volume per zone." "Footing — spread foundation that distributes column loads into soil." The glossary runs across disciplines, so the same mode explains a column on an S sheet and a diffuser on an M sheet.

Two kinds of callout — and they say which is which

The mode deliberately keeps two sources separate. Verified callouts anchor on text that literally exists on the sheet — the label "STM" that was already printed there gets explained in place. Visual callouts come from the AI looking at the drawing and identifying elements a text layer can't express — a pipe run's path, a building outline, a roofline. Those are flagged "(visual est.)" because the position is the model's estimate, not a verified anchor.

That distinction matters: you always know whether the callout is standing on ink that's really there, or on the AI's reading of the picture.

It's a lens, not a markup

Everything Engineering Mode draws is temporary. The callouts exist only while the mode is on, are tagged so they never mix with your real annotations, don't enter the undo history, and are stripped the moment you toggle the mode off. Turn it on to understand a sheet, turn it off to work on it — the file is never changed.

Each page is explained once and cached, so paging back and forth through a set doesn't re-run the analysis.

Who it's for

• PMs and coordinators reading disciplines they didn't train in
• Estimators who need to understand scope outside their own trade
• Owners and owner's reps reviewing sets they didn't design
• Junior staff learning to read plan sets sheet by sheet
• Anyone staring at a discipline's sheet thinking "what am I even looking at?"

What it is not

Engineering Mode explains what's drawn — it is not a plan review. It won't check the sheet against code, catch a coordination conflict, or tell you the design is wrong. For that there's AI Plan Review, which reviews against jurisdiction and discipline. Engineering Mode is the layer before that: making sure you understand what you're looking at first.