Count edges, openings, excavation edges and dangerous equipment from plan drawings, then check each location against the rule that applies.
Key takeaways
- Mark drops, holes, excavations and equipment before counting.
- Read heights from sections, elevations and level labels.
- Keep drawing references beside each count.
- Ask the designer to resolve missing dimensions and protection details.
The estimator has to pick those out and count them, and each count can change the quantities and the labor on a takeoff. This post walks through four items to count from the drawings, with the rule text for each. Each rule holds only where it is written, so check your own jurisdiction before you price anything.
Start by marking every drop on the drawings
Before you count any single item, mark every place on the drawings where a working surface drops to a lower level, every hole in a walking or working surface, every excavation, and every piece of equipment that a worker could fall into or onto.
A plan view may not give heights on its own. Use the elevation notes, section cuts, and level labels to find the height of each drop, and write that height next to the mark. Several of the rules below depend on a height or depth, so a mark without a number is not yet a count.
Then sort the marks into four columns on your sheet, one for each item below, so every count can be traced back to the rule that requires it.
Read heights from sections and elevations
Use section cuts and elevation views to read each height, and use the plan only to locate the mark. A section cut can show the floor, roof and grade levels in a slice through the building, so the difference between two levels can be read directly from it.
Level labels and elevation notes give the height of a surface above a reference point, such as the ground floor. Subtract the lower level from the working surface to get the drop. For example, if a deck surface is labeled 4 feet above the ground floor and the lower level is the ground floor, the drop is 4 feet, which is below the 6-foot threshold for the edge rule.
Some drops are hard to find in a plan view, such as a change in floor level inside a building or an edge along a roof. Check every section that crosses those areas, and if no section crosses one, add a note asking for one.
Edges with a drop of 6 feet or more
Under Oregon's rule, when employees are exposed to a hazard of falling 6 feet or more to a lower level, the employer must ensure that fall protection systems are provided, installed, and implemented, except where another standard permits otherwise.
The rule points to other standards for the criteria: 1926.502, 437-003-0502, 437-003-1502, and 437-003-2502. Check those criteria before choosing a system; the location count alone does not specify its design.
For the edge count, list every edge on the drawings where the drop to the lower level is 6 feet or more. An edge with a drop under 6 feet is outside this threshold, so it does not get counted under this item. Check it again under the other three items, since a shorter edge can still sit next to an opening, an excavation or equipment.
Keep a separate note for any edge whose height you cannot read from the drawings, and ask the designer before you count it. For related protection details, see the guide to guardrail specifications.
Openings: count every hole, regardless of height
Under Oregon's rule, each employee on a walking/working surface must be protected from tripping in or stepping into or through holes, including skylights, by covers or equivalent, regardless of height.
Count every hole you can find in a walking or working surface on the drawings, and do not drop a hole from the count because the work above or below it is less than 6 feet.
The rule also includes a note about skylights. A skylight or smoke dome is not considered a cover for this section unless it meets the strength requirements of 1926.502(i).
For each hole on the drawings, record its location, the surface it sits in, and whether a cover is shown or noted. If a cover is not shown, count it as an open item to resolve, not as protected. Use the floor opening checks when reviewing those details.
Excavation edges 6 feet or more deep
Under Oregon's rule, employers must use guardrail systems, fences, or barricades to protect any employee who might approach the edge of an excavation that is 6 feet or more in depth and is not readily seen because of plant growth or other visual barrier.
Oregon's rule has a second part for wells, pits, shafts, and other similar excavations. For those, employers must use guardrail systems, fences, barricades, or covers to protect any employee who might approach the edge when the excavation is 6 feet or more in depth. This part does not include the visual-barrier condition from the first part.
Put the two parts side by side on your sheet. The first part depends on whether the edge is readily seen, so note any plant growth or other visual barrier that the drawings or site notes show near the edge. The second part depends only on the depth and the type of excavation.
Check the phrase "similar excavation" in the full rule before you sort an excavation into the second group.
Work less than 6 feet above dangerous equipment
Under Oregon's rule, in addition to the fall protection requirements under 437-003-1501(1), each employee working less than 6 feet above dangerous equipment must be protected from falls into or onto dangerous equipment by guardrail systems or equipment guards.
A single location can therefore appear under more than one item on your sheet.
Mark the equipment that a worker could fall into or onto from a position less than 6 feet above it. Check the full rule and your project specifications before deciding which equipment to include.
Write the protection type next to each equipment mark, and write "not shown" if the drawings do not show one.
Handrail height and gap under UK rules
The Regulations that HSE describes require, for construction work, handrails with a minimum height of 950 mm, and any gap between the top rail and any intermediate rail should not exceed 470 mm.
This is a UK rule. Use these figures only for work under the rules HSE describes.
On the drawings, check each rail detail against both figures. Flag any detail where the rail height is below 950 mm or the gap between the top rail and an intermediate rail is more than 470 mm, since the HSE excerpt sets those as the limits.
Keep the triggers separate
The four items do not share one trigger, so the same location can be in or out of an item depending on which trigger it meets.
Read each trigger separately, and write the trigger on the sheet beside each count so the reason for every entry is visible.
A worked example with made-up numbers
This example sorts one hypothetical addition into the four lists. Suppose the addition has a roof deck 9 feet above the ground at its outer wall, a mezzanine edge 4 feet above the floor below, one skylight over a stair, one floor opening for a future lift, a pit 8 feet deep for a sump, and a tank 3 feet below the working platform. The numbers are made up for the example and are not taken from a real project or a rule.
The roof deck edge is 9 feet above the ground, which meets the 6-foot threshold in the edge rule, so it goes on the edge list. The mezzanine edge is 4 feet, so it stays off the edge list, but it is still checked against the other items.
The skylight and the floor opening both go on the openings list. Because a skylight is not considered a cover for this section unless it meets the strength requirements of 1926.502(i), the sheet should flag it until the designer confirms how it is protected.
The 8-foot sump pit goes on the excavation list, because its depth is 6 feet or more. Because it is a pit, it falls under the second part of the excavation rule, which has no visual-barrier condition. A 4-foot pit would fall outside both parts of that rule.
If the tank counts as dangerous equipment, the worker position 3 feet above it goes on the equipment list, because the worker is less than 6 feet above it. The sheet then records whether the drawings show guardrail systems or equipment guards for that position. If the tank were moved to 6 feet below the platform, the worker would no longer be less than 6 feet above it, so the entry would come off the equipment list under this rule.
Build the count into one takeoff sheet
Keep one sheet with four item groups: edges with a drop of 6 feet or more, holes in walking or working surfaces, excavations 6 feet or more deep, and work less than 6 feet above dangerous equipment. For each entry, record the drawing sheet, the height or depth you read, the item group, and the link to the rule.
Sort the entries before you price them. A location that appears under two groups, such as an edge next to an opening, should carry an entry under each group so that each rule's count is kept separate.
Keep the drawing-sheet references next to each count. If a later revision moves an edge or changes a level, you can find the entries that need to change without redoing the whole takeoff.
If the job falls under UK rules, add the handrail check as its own line, separate from the four Oregon-based groups.
Today, mark one drawing sheet, trace its dimensions to the sections, and list the unresolved questions below before pricing protection.
Related guides: Buried utility takeoff: three limits before bids · Public bid costs: 3 items to price outside unit rates · Rework costs: 3 items to price before a public job.
Questions to send the designer
What dimensions and cover details should you request?
Ask the designer for the height of every drop that a section does not show. Ask for the depth of every excavation, and whether a visual barrier such as plant growth is planned beside it. Ask which covers are planned for each hole, and whether any skylight or smoke dome is meant to serve as a cover.
What equipment and rule questions should you ask?
Ask which equipment the designer considers dangerous. Ask which rules the designer used, and whether the project specifications name a different rule for any item.
How should you check drawing coverage?
Ask whether the drawing set includes a sheet for each level, because a missing level can hide a drop.
How should you record the answers?
Write each answer on the drawing list with the date you received it, so the count can be checked later. If an answer does not match the drawings, note the conflict and keep both values until it is resolved.
Mistakes to avoid when counting
The first error is letting the 6-foot number carry over. Compare each drawing mark with its own item before assigning it to a group.
The second error is applying one jurisdiction's rule to another. Confirm the project jurisdiction before choosing the rule links for your sheet.
The third error is dropping a location from the sheet because it misses one threshold. Keep unresolved marks visible until you have checked all relevant groups.
The fourth error is treating a skylight as protected because it is drawn on the plan. Ask for the cover detail rather than treating the plan symbol as confirmation.
Checking the finished count
Before you release the count, check each entry against its rule link and the drawing sheet it came from. Confirm that every height and depth was read from a section, elevation or a note, and that no value was estimated without saying so.
Then sort the list by rule and read each group on its own. An empty group is worth a second look, since it may mean a sheet was not reviewed. If a group grows during review, record the new entry with its source before you change any total.
Finally, compare the count against the excerpts in this post. Each entry should cite one of the linked rules, and no entry should rest on a threshold that does not appear in them.
How to use the links in this post
Open the linked page before you count, because each excerpt here is only part of its page. The pages cover more than the sentences quoted, and the count depends on the full wording and on any defined terms.
Read the linked page for the words that set your threshold, such as 6 feet or more, regardless of height, or less than 6 feet, and compare them with the drawing values. Note the date you read each page, since rule pages can change.
If a page has moved or changed since this post was written, check the official version in its place.
What this post does not cover
This post does not cover every fall protection requirement; it covers four Oregon items and one UK handrail check.
The Oregon rule refers to other sections, including 1926.502 and 437-003-0502, for the criteria its fall protection systems must follow. Read those sections before specifying what a guardrail, cover, or guard must look like or how strong it must be.
Several of the rules here carry conditions of their own. Read those conditions in the full text before you finalize a count.
Confirm which rules govern your project before you finalize a count.