This year’s release of Navisworks has a feature that we think will change the way you work and bring intelligence to your Information packed models. Model based quantification isn’t new, but combining it with the ability to combine Building Information Models from multiple file formats, take quantities directly from the Building Information Model, then run change analysis as the model changes we think is an important part of streamlining this generally time consuming and laborious process. In a short series of posts we’ll explain what Quantification in Navisworks is and how to set it up, how to take off from your Building Information Model, and how to analyze changes when new iterations of the model come in.
Navisworks is already used to bring together different disciplines into a single federated model. Once you have this you can take off elements of the model to constructible Items
, which may contain Resources
such as materials, or preliminaries, this will then combine the quantity data into a reporting format which can be exported into a spreadsheet or an API connection can be built for use in an estimating system so you can then start looking to cost the project directly from the Building Information Model. When changes take place in the model, Change Analysis
can be run to ensure you have the latest correct quantities and can quickly find any new or deleted items from your takeoff. This brings the world of BIM to a new group of people who may never have had access to more than paper drawings or a 2D plan of the model and been disconnected from the process of modifications and refinements of the design.
Out of the box the 2014 release of Navisworks is set up to support quantities from Revit and DWF files; these would include Length, Width, Thickness, Height, Perimeter, Area, Volume and Weight if these are available in the properties, as well as counts of the items taken off. These properties are already in your models, in this example the Volume, Area and Length can be seen in the Element tab of the Properties window.
You can add resources to items, to build up a picture of the quantities of materials or labor of an item and use formulas to calculate figures based on properties. For example, this image shows the walls in the project are made up of several components and the relevant quantities are calculated based on the Area of the wall.
You can then export out these quantities to an Excel spreadsheet which you can then use in estimating software. When there are changes to the model you can run Change Analysis to see what has changed and how, with callouts detailing the change to allow you to verify that the change is an expected one.
Over the coming weeks there’ll be a few posts to talk you through how to setup catalogs, perform takeoff, and export your quantities as well as some more advanced posts about bringing through additional quantities. We’d welcome any feedback you have on this tool by emailing us at firstname.lastname@example.org