Custom formulas are a must when it comes to Revit generating a Cost for Materials using units and calculations that might be specific to a material’s properties within your Material Cost Estimation Reports. Here are three custom calculations and conversions to determine the costs of three common materials: concrete, walls and roofs.
To get each Cost Schedule started begin under the View Tab. First, click Schedules, then click Schedule/Quantities and, finally, select the Category you want. In this case, we’ll be looking at Floors, Walls and Roofs.
Calculating Costs for Concrete
How much concrete do you need to pour a slab? How much is that going to cost you? After you’ve chosen the Floors category, add the scheduled fields Cost and Volume from the list of available fields to begin calculating the Cost for Materials.
How much concrete do you need to pour a slab? How much is that going to cost you? After you’ve chosen the Floors category, add the scheduled fields Cost and Volume from the list of available fields to begin calculating the Cost for Materials.
Concrete is measured by Cubic Yards. So first you’ll need to convert the volume of concrete you have into the number of Cubic Yards needed using the formula:
Cubic Yards Needed = Volume / 27
Remember, a Cubic Yard is 1ft3 and Volume = Length x Width x Depth. To determine the Total Cost of Slab Concrete, you will need a second calculated value using the formula:
Total Cost of Slab Concrete = Cubic Yards Needed * Cost
After you have created the Schedule using these custom formulas, enter Cost into your Schedule and Revit will calculate the Total Cost of Slab Concrete using the custom formulas you created.
Calculating Costs for Walls
Cost Schedules for exterior walls are rather simple to determine. After you’ve chosen the Walls category, you’ll add a few parameters. From the list of available fields, add the Family and Type field (if you have more than one type of wall), Length and Cost to your scheduled fields. To calculate the Cost of Material, use the following formula:
Cost Schedules for exterior walls are rather simple to determine. After you’ve chosen the Walls category, you’ll add a few parameters. From the list of available fields, add the Family and Type field (if you have more than one type of wall), Length and Cost to your scheduled fields. To calculate the Cost of Material, use the following formula:
Cost of Material = Length * (Cost) / 1
After you have added the custom formula above to your Schedule, enter Cost and Revit will calculate the Cost of Material using the custom formula you created.
Calculating Costs for Roofs
Now, how do you calculate the cost of a roof? Roofers will often use what are called Squares. Contractors generally charge a certain amount per square. A Square is calculated as:
Now, how do you calculate the cost of a roof? Roofers will often use what are called Squares. Contractors generally charge a certain amount per square. A Square is calculated as:
1 Square = Area of Roof / 100 sq ft
To calculate the cost of the roof, first choose the Roofs category and, using the formula above, select Area and Cost from the list of available fields. Then, create your Calculated Value called Square. With Square calculated, you can now move on to determine Cost of Roof System, which is defined as:
Cost of Roof System = Square * Cost
After you have added the custom formula above to your Schedule, enter Cost and Revit will calculate the Cost of Roof System using the custom formulas you created.
Digital-Tutors members can watch step-by-step how to create and format cost schedules using these calculations in the tutorial Using Schedules for Material Cost Estimation, one of many Revit tutorials in the Digital-Tutors training library.
Source: http://blog.digitaltutors.com/
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