General-purpose vs trade-specific AI takeoff

The difference in one sentence

General tools are trained to find geometry that every trade shares (rooms, walls, openings, repeated symbols). Trade-specific tools are built around one trade's documents and line items, so they can tell you when the schedule, the plans and the specification disagree about the same item.

A general tool is usually enough when

• Your quantities are areas and lengths: flooring, drywall, paint, roofing, concrete flatwork.
• Your counts are of symbols that look the same everywhere they appear, and the legend tells you what each one is.
• Each item's price does not change with information held in a different document.
• You bid several trades, or you are a general contractor checking subcontractor numbers.
• You need public pricing and a self-serve trial to get started this week.

You need purpose-built software when

• A schedule decides the price, and items on the plan can be missing from it, or the other way round. Door, window and fixture schedules are the common cases.
• A specification section changes what the schedule says: a hardware set defined in 087100, an approved manufacturer list, a substitution rule.
• One item on the plan expands into many priced line items (one door opening becomes a leaf, a frame and a dozen pieces of hardware).
• Your output has to go into a trade system (Comsense, eMullion or SFH for door hardware) without re-keying.
• Addenda reissue part of the set and you need to know exactly which items changed.

Tests you can run on your own plans

Take a past job in your trade, one you already priced, and check these in a trial. Each one has a yes or no answer.

1. The orphan test. Find an item on the plan that is missing from the schedule. Does the tool flag it, or only count what the schedule lists?
2. The spec test. Find an item whose schedule entry points to a spec section (a hardware set number, a finish code). Does the tool read the spec and expand it, or leave the reference as text?
3. The conflict test. Find two documents that disagree about the same item. Does the tool show you both sources side by side, or pick one silently?
4. The addendum test. Run the original set and the addendum. Does the tool list what was added, removed and changed?
5. The export test. Send the result to the system you price in. How many columns did you have to fix by hand?

If your trade's price only depends on tests 4 and 5, a general tool will likely do. If tests 1 to 3 decide your number, use a tool built for your trade.

Division 8 as the example

Doors, frames and hardware are the clearest case for a trade-specific tool. A door schedule row points to a hardware set defined in the 087100 specification, a fire label shown on the life safety plan and a wall type in the partition legend. Counting door symbols gets you the number of openings, not the price. See AI takeoff for doors, frames and hardware for what a Division 8 tool has to do.

Which ranked tools are which

Some general tools have pages for specific trades. Read what the page says the tool does: a trade page that describes counting openings by type is still general detection, not reading the trade's documents.

See the full ranking or the questions to ask before you buy.