Schedules & Quantities

Schedules & Quantities

Overview

In this lesson, you will explore ways of creating tabular views called schedules and summarizing information about the building elements through groupings, sorting, and calculating values.

One of the key benefits of the BIM workflow is the ability to manage not only the drawings, but also the tabular information in the project database. With BIM we can dynamically generate and update schedules of building elements to support many purposes, for example:

  • Improving the visibility and predictability of costs and material quantities.
  • Facilitating construction management tasks such as cost estimating and, procurement.
  • Summarizing building performance and LEED certification data.

Since the information flow in Revit is bi-directional, the data from changes in the model flows automatically into the schedule, and changes in the schedule automatically flow back into the model. The model data can be edited through our schedules, and this technique should be used when it is easier or more efficient than doing so selecting and changing elements in graphical model views.

Creating and Presenting Models through Schedules

A schedule presents a tabular view of the project data, which can be filtered, grouped, and formatted to fit your needs. Schedules can list every instance of the building elements or collapse multiple instances into single rows, based on the schedule's grouping criteria. Since Revit software creates a database of the elements, building a schedule is very similar to creating a database query.

Schedules should be formatted to meet the needs of the end-user, whether they are engineers, designers, clients, or code officials. Schedules are often placed on sheets either alone or accompanied by the corresponding model view. Finally, schedules can be exported to many formats, including delimited text files compatible with spreadsheet software and database formats.

Enhancing and Adding Information to Schedules

By adding information, or “intelligence,” to schedules, we optimize the workflow and maximize the utility of the building model. In this way, enhanced schedules can be the basis of analysis for many goals of project.

Since model elements store all information about their physical properties, we can add information fields or parameters to model element types--for example, type mark, size, material, fire rating, and any other custom data fields we need. These parameters can be either user entered, such as text fields, or calculated values that depend on other parameters.

Adding calculated values to schedules avoids the errors and unnecessary time spent performing manual calculations. A simple example of a calculated value formula would be a width parameter set to equal twice the height of an object. In practice, formulas can be used in many ways, both simple and sophisticated. For example, formulas can be used to:

  • Calculate area or volume of geometry
  • Create a clearance dimension parameter controlled by element size
  • Convert continuously variable values into integer values
  • Add shelves as the height of casework increases
  • Add diagonals in an open web joist as the length increases

Formula Guidelines

Formulas support the following arithmetic operations: addition, subtraction, multiplication, division, exponentiation, logarithms, and square roots. Formulas also support the following trigonometric functions: sine, cosine, tangent, arcsine, arccosine, and arc tangent.

The valid formula abbreviations for arithmetic operations and trigonometric functions include:

  • Addition: +
  • Subtraction: ─
  • Multiplication: *
  • Division: /
  • Square root: sqrt: sqrt(16)
  • Exponentiation: ^: x^y, x raised to the power of y
  • e raised to an x power: exp
  • Logarithm: log
  • Absolute Value: abs
  • Sine: sin
  • Arcsine: asin
  • Cosine: cos
  • Arccosine: acos
  • Tangent: tan
  • Arctangent: atan

You can enter integers, decimals, and fractional values in formulas, using normal mathematical syntax, as shown in the examples below:

  • Length = Height + Width + sqrt(Height*Width)
  • Length = Wall 1 (11000mm) + Wall 2 (15000mm)
  • Area = Length (500mm) * Width (300mm)
  • Volume = Length (500mm) * Width (300mm) * Height (800 mm)
  • Width = 100m * cos(angle)x = 2*abs(a) + abs(b/2)
  • ArrayNum = Length/Spacing

Lastly, we can even introduce conditional statements to our schedules. A conditional statement uses the following structure: IF (<condition>, <result-if-true>, <result-if-false>). And it means that the values entered for the parameter depends on whether the condition is satisfied (true) or not satisfied (false).

Conditional statements can contain numeric values, numeric parameter names, and Yes/No parameters. You can use the following comparisons in a condition: <, >, =. You can also use Boolean operators with a conditional statement: AND, OR, NOT. Currently, <= and >= are not implemented. To express such a comparison, we can use a logical NOT. For example, a<=b can be entered as NOT(a>b).

The following are sample formulas that use conditional statements.

  • Simple IF: =IF (Length < 3000mm, 200mm, 300mm)
  • IF with a text parameter: =IF (Length > 35', “String1”, “String2”)
  • IF with logical AND: =IF ( AND (x = 1 , y = 2), 8 , 3 )
  • IF with logical OR: =IF ( OR ( A = 1 , B = 3 ) , 8 , 3 )
  • Embedded IF statements: = IF ( Length < 35' , 2' 6" , IF ( Length < 45' , 3' , IF ( Length < 55' , 5' , 8' ) ) )
  • IF with Yes/No condition: = Length > 40 (Note that both the condition and the results are implied.)

Learning Objectives

After completing this lesson, you will be able to:

  • Explore the application of schedule configuration rules to create schedules to meet various audiences and information needs.
  • Understand how to use the completed schedule to edit the model through BIM’s bi-directional information flow
  • Appreciate the value of adding custom information to model elements, thus making our model “smarter,” in ways that can enable schedules to host and be the basis for useful engineering calculations.
  • Explore various modes of exporting the schedules to be shared and used by other team members.

Tutorials

Creating and Presenting Model Schedules

In this exercise, you will learn how to:

  • Create schedules of model elements such as doors, windows, roofs, walls, curtain walls, furniture objects, and so on.
  • Configure schedules by changing their fields, sorting logic, grouping, and format.
  • Place schedules into printable sheets either alone or with appropriate graphical displays.
  • Export the schedules in common formats, such as delimited text files, which can be used in Microsoft Excel.
image

Figure 2.5.1 Adding fields to a door schedule

Video Tutorial
Student Exercise
  • Create a schedule of the floor elements that includes the following fields: level, family, type, and area.
  • Sort and group the schedule rows first by level and then by type. Configure the grouping and sorting to display subtotals for each level and for each type within a level. Also, display a grand total at the bottom of the schedule.
  • Format the schedule to calculate totals for the area field.
  • Export the schedule as a delimited text file and import it into Microsoft Excel or another spreadsheet program.
image

Figure 2.5.2 - Floor schedule grouped and sorted by level and type with area subtotals

Enhancing and Adding Information to Schedules

In this exercise, you will learn how to:

  • Add parameters to building elements to capture additional design information needed for analysis.
  • Define new parameters as calculated values.
  • Use formulas to compute values based on other parameters.
image

Figure 2.5.3. Entering information into the new window parameter

Video Tutorial
Student Exercise
  • Open the Curtain Wall Panel Schedule and add two new parameters:
    • Orientation: a text field describing the compass orientation of the panel, similar to the field added in the video tutorial
    • Glazing Area: a calculated value showing the exposed glazing area for each panel. For this calculation, assume the exposed glazing area is 95% of the panel area.
  • Open the Exterior Curtain Panels view and assign the orientation to each panel by filling in values for the new orientation property.
  • Filter the schedule to only show exterior curtain wall panels, which all have a type mark of A.
  • Group the schedule rows by the orientation field and display subtotals for each orientation as well as a grand total for the entire schedule.
  • Format the schedule to calculate totals for the Glazing Area field.
  • Export the schedule as a delimited text file and import it into Microsoft Excel or another spreadsheet program.
image

Figure 2.5.4. Curtain Wall Panel Schedule grouped by orientation

Assessment

Creating and Presenting Model Schedules

  • Can you change an element’s model category or type from within a schedule?

You cannot change an element’s model category from within a schedule, but you can change its family and type if these fields appear in the schedule. Family and type typically appear as drop-down menus listing all available types currently in the model, so new types can be selected from the menu in the same way they are selected using the Type Selector.

  • Is the schedule a frozen snapshot of a particular stage in the design process or does it dynamically update as the model changes?

Schedules are live model views that are dynamically updated as changes are made to the building model. If you want to save a static snapshot of the schedule data at a particular point in time, you can export it as a delimited text file.

  • Can you use schedule views to find or deleteelements?

Yes. Each row in the schedule represents a building element in the model. You can select a row, then right-click to access commands that let you show or delete that element.

Enhancing and Adding Information to Schedules

  • Can schedules be copied or transferred between projects?

Yes. You can and should standardize your schedules between projects. You can used the clipboard to copy and paste schedules between projects. Or you can add a schedule to a project template file to automatically include it in new projects.

  • Give examples of calculated values that would be useful for different participants on the project team.

Many answers are possible. Calculated values provide great flexibility to compute the numbers of greatest interest for each discipline involved in the project.

For example, construction managers often focus on project costs, so calculations which tabulate the total cost of building elements or summarize square footage cost estimates are typically useful to them.

Similarly, schedules with calculated values can be used to compute percentages and values needed for LEED analysis and certification – for example, estimating the water or energy savings available through high efficiency fixture selection or innovative alternative design strategies.

  • Canschedules be used to automatically create a complete material take-off?

Schedules in Revit can be used to compute key quantities, but they typically do not provide the level of detail needed to create a complete material take-off. The tools available in Autodesk Revit focus on modeling the building information and supporting design tasks.  The information in the building models created can be used by other software solutions, for example Autodesk Quantity Takeoff, to perform a more detailed analysis and quantification of the design.

Key Terms

Key Term
Definition
Schedule
A live view of project elements within the model that can be used to enumerate items, including building objects (walls, doors, windows etc); calculate material quantities or areas and volumes; or list project sheets, text notes, keynotes, and so on.
Tag
A text label for elements such as doors, walls, windows, that displays information about that element in a view. Tags are typically used to provide a reference between objects in a view and a row in a schedule of the building elements.
Parameter
A data value that describes a property of a building element.  Parameters are also commonly called fields.
Calculated Value
A parameter whose value is calculated based on a formula that relates other parameters of the same element.