BIM based visual estimation with Quantity takeoff

20th March 2010

BIM based computerized quantity take-off and cost-estimating solution has flourished in the last 4-5 years. Quantity take off procedure can be enhanced with BIM as estimate of the quantities are derived from BIM models and the model contains the information on all the objects in the building in addition to their dimensions.

It is a very useful that can be widely utilized for BIM Model, CAD Architecture, and Civil 3D in different purposes like estimation and costing, initial pricing, report tabulation of materials, bidding, unit cost for specific items, time spent counting within a project, measuring items within a project, labor costs and estimates project costs.

With Quantity Takeoff, estimators can be benefited with property data to measure, count, and price building objects for example walls, doors, and windows, automatically or manually. The results will be printed, exported to Microsoft® Excel® software, or published to DWF™ file format.

It can be also utilized for evaluating the building design, grouping objects into proper assemblies for construction, setting congregation and item variables, and pricing the objects by taking off these assemblies or items.

Quantities that have already included the estimate are represented by a $ sign, and all the cost items are verified visually in the estimate with colors in the 3D view at any point and keep away from over- or under-estimating. In the case of any change is made to the design, the cost items and the estimate can be updated automatically as all the objects and quantities are connected with cost items.

The estimator can open up a Timberline database, and drag and drop the quantified objects generated in the previous step into Timberline assemblies or items, resulting in detailed cost items taken-off into a Timberline estimate file.

QTO can be organized to perform any size estimate and for checking a BIM model for precision. Data is transferred to any of the project management, or estimating systems, or amount produced as an Excel “spread sheet” file. QTO will also receive component information from cost analysis services for instance RS Means.

Unlimited component subassemblies facilitate categorization and counting of materials to an important level of detail. The Search Takeoff function make possible for quick takeoff of intellectual drawing objects, whereas the Manual Takeoff function sustains non-intelligent image formats for instance JPG and TIF.

Quantity Takeoff Process:-

• Place the paper plans for digitization on the tablet. In the case of working with scanner version scan the plans. In the case of on-screen version, load the image. On-screen programs should work with all file types, including CAD Drawing, PDF, and TIFF
• Initiate the Take-Offs program
• Enter the scale units, English or metric
• Enter the scale or compute the scale from the plans by digitizing a recognized distance.
• Select the digitize area, length, perimeter, counts, multiple line segments or sum of line segments
• Digitize the item using the digitizing tablet
• Digitizing can be point to point, or continuous curves.
• Digitized items are put on view on screen while digitizing
• The software estimates the item from the digitized data. Do again for other items.
• Print a report with an image diagram of the digitized data and a table of results.
• If contractors get CAD Drawing files, certain programs may enable them to perform a direct CAD import without the need to digitize.
• One can export the take-off result by pressing the excel button to the excel spreadsheet. The report can also be published to DWF file format.