Electrical & Construction Symbol Legend + Takeoff QA Checklist
A plain-English reference to the symbols estimators count most, and a checklist to make your count defensible before it goes in a bid. This page and its one-page PDF are a free preview; the full legend comes with early access.
One thing first: symbol shapes are not universal. Every drawing set carries its own legend (often the E0 or “symbols & abbreviations” sheet), and offices differ. Use this as a reference for what the common devices are and where they show up, then always count from the project’s own legend. That’s exactly why SimplyCount is self-learning: you teach it your legend once and it counts your symbols, not a generic set.
Common construction symbols, by discipline
A preview: the first symbols in each of the 6 disciplines. The full legend has all 33.
Electrical: power & lighting
| Symbol / device | What it is | Where you’ll see it |
|---|---|---|
| Duplex receptacle | A standard two-outlet wall power receptacle. | Power plans, usually the most-counted device on a job. |
| GFCI receptacle | A ground-fault receptacle that trips on a fault; required in wet locations. | Kitchens, baths, exterior, mechanical rooms. |
| Quad / double-duplex receptacle | Four outlets ganged in one location. | Offices, workstations, AV walls. |
| Dedicated / special-purpose receptacle | A receptacle on its own circuit for one load, usually labeled. | Appliances, equipment, IT rooms. |
+ 9 more symbols in the full legend
Architectural: doors, hardware & openings
| Symbol / device | What it is | Where you’ll see it |
|---|---|---|
| Door (single / double) | A door opening; each leaf is keyed to the door schedule. | Architectural floor plans + the door schedule. |
| Door tag / mark | The number or letter in a bubble that keys a door to its schedule (type, size, fire rating, hardware set). Count these. | Floor plans, then reconcile against the schedule. |
+ 4 more symbols in the full legend
Plumbing
| Symbol / device | What it is | Where you’ll see it |
|---|---|---|
| Fixtures (water closet, lavatory, urinal, sink) | Plumbing fixtures, keyed to a fixture schedule. | Plumbing fixture plans. |
+ 3 more symbols in the full legend
Mechanical / HVAC
| Symbol / device | What it is | Where you’ll see it |
|---|---|---|
| Diffuser / grille / register | Supply and return air distribution devices. | Mechanical plans and RCPs. |
+ 3 more symbols in the full legend
Fire protection
| Symbol / device | What it is | Where you’ll see it |
|---|---|---|
| Sprinkler head (pendent / upright / sidewall) | The discharge device; orientation matters for the count. | Fire-protection plans. |
+ 1 more symbol in the full legend
Fire alarm, low-voltage & security
| Symbol / device | What it is | Where you’ll see it |
|---|---|---|
| Smoke / heat detector | Initiating devices. | Fire-alarm plans. |
+ 3 more symbols in the full legend
The 9-step takeoff QA checklist
Run this before any count goes into a bid. The first 3 steps are here; all 9 are in the full legend.
- Read the legend sheet first. Every set defines its own symbols (usually the E0 or “symbols & abbreviations” sheet). Count from the project’s legend, not a generic chart.
- Confirm you’re on the latest revision, and note the drawing scale before you start.
- Count one symbol type at a time across every sheet; don’t mix types in a single pass.
Get all 33 symbols and all 9 QA steps
The full PDF covers every symbol across all 6 disciplines and the complete 9-step takeoff QA checklist. It comes with early access: request it with your work email and it is in your account straight away, while the team reviews your request.
Free during early access · Your work email · No credit card
Common questions
Are construction symbols standardized?
What’s the fastest way to count symbols accurately?
How do you count doors on a plan?
Can I get this as a PDF?
Stop counting symbols by hand
Request early access with your work email. The team reviews every request, nearest bid deadlines first. Then run your first plan and see a number you can defend. 53 symbols · 21 pages · 11 minutes.
Free during early access · Your work email · No credit card · Counting runs on your machine