Drawing takeoff
How to count electrical symbols without losing your place
An interruption can leave you unsure whether a symbol was counted, skipped or added twice. Give each count a visible place on a working copy and leave a short checkpoint before you move away.
This guide sets out a manual counting routine for estimating. Use the drawing’s own legend and agreed scope, then reconcile your marks with the tally before pricing.
1. Fix the sheet, symbol type and counting area
Record the drawing number and revision on both the working copy and the tally. Choose one bounded area and one item type for the next pass. For example, count the luminaire type labelled LT in Room A, then start a separate pass for another type. Keep the unmarked source drawing available for comparison.
Read the legend and nearby notes first. Similar-looking symbols may represent different work. Keep existing, new, removed and uncertain items separate where the drawing or quotation scope distinguishes them. Put an unclear mark in a questions list with its location rather than guessing its type.
Set up the areas and item columns with the room-by-room electrical takeoff checklist. If small labels are blurred, use the drawing readability checks for a scanned sheet before starting.
2. Choose a route and mark as you count
Pick a route you can retrace, such as left to right across the first strip of the room, then right to left across the next. Use a visible boundary so you can tell which side has been checked. Avoid jumping to an isolated symbol elsewhere before finishing the strip.
- Find a symbol and check it against the chosen legend entry and scope.
- Give it a clear mark on the working copy without covering its label. A short sequence number can link the mark to your tally.
- Add one item to the matching tally, then move to the next symbol. Keep marking and tallying together.
- At the end of the area, compare the marked symbols with that area’s subtotal before carrying it forward.
If you use colours, write down what each colour means and add text or a distinct mark as well. For example, “counted”, “question” and “outside this pass” should be distinguishable when someone prints the sheet in black and white. Choose any annotation method you can read clearly on your working copy.
3. Leave a checkpoint before an interruption
Save the marked copy and tally together. Write the last completed location and the next location to inspect. A subtotal by itself is insufficient because it does not show where the count stopped.
| Field | What to record | Fictional example |
|---|---|---|
| Drawing and revision | Exact source used for this pass | E-02, revision C |
| Area and type | Boundary and legend entry | Room A, LT luminaires |
| Completed marks | Last mark already in the tally | 01–03; last completed 03 at top right |
| Saved subtotal | Count already carried in this pass | 3 LT luminaires |
| Next position | First symbol still to inspect | 04 at bottom right |
| Open questions | Separate locations needing clarification | None for this pass |
| Resume check | Marked copy and tally agree | Continue at 04 with subtotal 3 |
On returning, open the recorded revision, locate the last completed mark and compare the saved subtotal with the marks. Start from the written next position. If the marks and tally disagree, recount that bounded area and replace its subtotal. Do not add a fresh recount to the old subtotal.
4. Walk through the fictional six-symbol example
The illustration uses six circles labelled LT. In this fictional sheet’s legend, each LT represents one luminaire. These symbols and the route are invented to explain the counting method.
The top row runs 01, 02, 03 from left to right. The lower row continues 04, 05, 06 from right to left. After marking 03, the tally is 3. Pause with “next 04, bottom right” in the record. When work resumes, inspect and mark 04, 05 and 06, adding 3 more. The completed tally is 3 + 3 = 6 LT luminaires.
The sequence numbers are your counting marks, not additional equipment. If a second view shows the same installed item, compare references before including it again. Keep any unresolved identity or scope question visible for review.
5. Reconcile before transferring quantities to the quote
- Confirm every intended area and item type has a completed pass or an explicit open question.
- Compare each pass subtotal with its marked symbols, then add the subtotals by item type.
- Check overlapping plans, details and schedules for repeated views of the same item.
- If the drawing revision changes, identify the affected areas and review those counts before reusing the tally.
- Transfer only the reviewed quantities and clearly record remaining assumptions or exclusions.
With Quotractor, review AI-assisted quantities against the drawing and job scope before using your own rates. Keep this working count record alongside your estimate, then use the electrical quotation template outline to present the reviewed work clearly.