Quantity takeoff software: how I work with Acrobat Pro, AutoCAD, Revit, Navisworks, Autodesk Takeoff and AiN Engine
Quantity takeoff software is part of my daily work as a quantity surveyor, and I choose between the tools by what the project gives me: Acrobat Pro when there is only a PDF, AutoCAD when there is a drawing, Revit and Navisworks when there is a model, Autodesk Takeoff when the drawings and the model are managed in Autodesk's cloud, and AiN Engine, the software I develop, to link the quantities to the items of the bill. What follows is my own use of and experience with each tool, not a list of everything it can do. Each tool has a detailed page of its own.
Quantity takeoff software: what I measure in each tool
The table sums up what I use each tool for, what comes out of it, and what I check before a number goes into the bill of quantities.
| Tool | What I use it for | What comes out | What I check |
|---|---|---|---|
| Acrobat Pro, on a PDF | Lengths, perimeters and areas when there is only a drawing | Comments with the values, and an export to a file that opens in Excel | The scale, against a dimension written on the drawing |
| AutoCAD | Areas, lengths and block counts from the drawing | A table inside the drawing, or an Excel file | Closed boundaries, layers and drawing units |
| Revit | Quantities of elements and materials from the model | Schedules, and an export to a text file that opens in Excel | Joins, openings and finishes that were not modelled |
| Navisworks | Takeoff across several models, and measuring on sheets | A takeoff workbook, and an export to Excel | Properties that were not exported, and duplicates between models |
| Autodesk Takeoff | Measuring in the cloud, on PDF sheets and on models | One inventory of quantities, and an export to Excel | Duplicated pipes and ducts, and elements added in a new version |
| AiN Engine | Model elements by category, type and level, and the items of the bill | A bill of quantities in Excel, with a source for every quantity | Whatever is missing in the model is marked as missing, and I check it |
PDF and Acrobat Pro: measuring on the drawing
When all I get is a PDF drawing, I measure in Acrobat Pro: the distance between two points, the perimeter of a polyline and the area of a shape I mark. Before the first measurement I set a scale ratio and a unit, and I check it against a dimension written on the drawing, because a wrong ratio distorts every number measured after it. Each measurement is saved in the file as a comment with the calculated value, and I export all of them to a file that opens in Excel. The details, including my checks, are on the page on the Acrobat measuring tool.
AutoCAD: areas, lengths and counts from the drawing
When there is an open drawing, I measure in AutoCAD itself. The measuring commands give distance, area, perimeter and volume, and a click inside a closed area shows its area and perimeter. The Data Extraction wizard builds me a table inside the drawing, or an Excel file, with block counts. Before I trust a number, I check three things: that the boundary is closed, because for an open polyline the area is calculated as if it were closed with a straight line; that the layers do not mix items; and that the drawing units are right. For a whole building I developed an AutoCAD add-in that exports by floor, described on the page on AutoCAD quantity takeoff.
Revit: schedules from the model
From a Revit model I take quantities from schedules: a schedule for each category, with count, length, area and volume, and a material takeoff that breaks each element into its layers and materials. I export a schedule to a delimited text file that opens in Excel. In my experience the number looks precise, but it is calculated by the software's own rules, not by the method of measurement: joins between walls and floors change volumes, openings are deducted with no threshold, and whatever was not modelled, such as plaster or waterproofing, simply does not exist. These behaviours, and how I check them, are on the page on quantities from a Revit model.
Navisworks: takeoff across several models
When a project has several models, for example architecture, structure and building services, I bring them together in Navisworks and take them off in one workbook. Quantification takes the elements from the model with their properties, lets me add by hand whatever does not exist in the model, and also measures lengths, areas and counts on 2D sheets. I export the result to Excel, and when a new version of the model arrives I run a change analysis. The first thing I check is duplication: a slab that exists in both the architectural and the structural model is counted twice. The details are on the page on Navisworks quantity takeoff.
Autodesk Takeoff: measuring in the cloud
When a project's drawings and model are managed in Autodesk's cloud, I also work with Autodesk Takeoff, now called Forma Takeoff. On PDF sheets I measure lines, areas and counts, from the model I take element quantities, and all the results build up in one inventory that I export to Excel. Here too I check: Autodesk itself documents cases where pipes and ducts from a Revit model are counted twice, and cases where elements added in a new version of the model do not enter the takeoff on their own. The product itself is described on Autodesk's product page.
AiN Engine: from the model to the bill, with a source for every quantity
AiN Engine is the software I develop and work with on every project that has a Revit model. Its Data Takeoff window groups the elements by category, type and level, with count, area, length and volume, and marks what is missing instead of writing zero. From there I map the quantities to the items of the bill, and every line stays linked to its elements. When there is no model, AiN Engine also works with PDF and DWG drawings: AI suggests quantities, and I check and approve them. The AiN buttons inside Revit are explained on the page on the AiN ribbon in Revit, and the takeoff window on the page on Revit quantity takeoff.
Every tool measures by its own rules. No quantity takeoff software knows the method of measurement in your contract. That is why every quantity that comes out of a tool is cross-checked against the drawings and against accepted ratios before it goes into the bill, as explained on the page on cross-checking quantities.
A quantity surveyor may be an engineer or a registered building technician, like Yaakov Avital. In my work as a quantity surveyor for construction projects I measure the quantities the way a contractor measures them, in each of these tools. Pricing and estimates are an extra service: verbal feedback on prices together with the client, with no commitment.
The software names on this page are trademarks of their owners, and this site has no connection with them.
Frequently asked questions
Is this a list of everything these programs can do?
No. It is what I do with each program and what I have learnt about it in my work as a quantity surveyor. The full capabilities are on the makers' websites.
Which quantity takeoff software suits me best?
It depends on what you have. With only a PDF, I measure in Acrobat Pro. With tidy AutoCAD drawings, I measure in the drawing itself. With a model, the quantities come from Revit, Navisworks, Autodesk Takeoff or AiN Engine. On one project I usually use several tools.
Can I get a bill of quantities in one click?
No. Software produces quantities of what was modelled or drawn, by its own rules. Whoever prepares the bill decides which item each quantity belongs to, completes what is missing in the model, and checks the numbers against the drawings.
What do I do when two tools give different numbers?
I find out why. Usually the difference comes from a different measurement rule, for example deducting openings, or from an element measured twice. The gap itself is information, and I record it next to the quantity that was chosen.
Have a project? Tell me briefly what the project is and what already exists. When the project is a good fit, I usually reply with focused questions and a written quote.
Contact me for a quote* Created with AI for marketing, for illustration only. Not reviewed by Yaakov Avital and not professional advice. Every project must be checked on its own by a professional quantity surveyor and an engineer.