Dear Community members,
Have you ever wondered how you can easily calculate the total area covered by multiple roof elements, or its percentage, accounting for any overlapping sections? The Tip of January is here to answer that, with a solution shared by @Steve Jepson.
The collaborative solution posted in the forum provides an accurate and verifiable result, with techniques from Steve and our moderator @Barry Kelly.
Solid Element Operation
Steve suggested leveraging Solid Element Operations (SEO) to subtract holes in a Slab (with upward extrusion), by using items in a Layer Combination as Operator, for example. Scheduling the top surface area of the Target streamlines the process of determining rainfall area.
Properties and Schedules
Properties are optional, user-defined data assigned to an Element/building material to provide additional searchable information about it. To create and customize Properties, use the Property Manager (Options menu). Note that Property availability depends on the Classification of each Element/material.
Properties can help you easily document total site area, including, for example, permeable and roof rainfall area percentages.
The purpose of each Property used in this demonstration is defined as such:
- Schedules (True/False): allows our schedule to only pick the semi-transparent slab used to determine the roof rainfall area
- Rainfall area (Area, expression): calculates the rainfall area by subtracting the permeable area from the total site area
{Property:Slab/Surface Area of the Slab Top (Gross)} - {Property:Slab/Surface Area of the Slab Top (Conditional)} - Rainfall percentage (Number, expression): calculates the rainfall area percentage.
( {Property:Tip of the Month/Rainfall area} / {Property:Slab/Surface Area of the Slab Top (Gross)} ) * 100
In our Scheme settings, the Property “Schedules” appears as a criterion for filtering down elements to only show the slab we are interested in.
The other two Properties we’ve created appear as fields. The results of this example are the following:
In addition to the process described above, Steve also uses fills to verify automated data:
While some manual input may be required initially, this method offers efficient, adaptable, and verifiable results.
A thank you goes to Steve for sharing his knowledge and winning the Tip of January! The content above is based on @Paul Roper’s original thread.
Stay tuned and continue to share your knowledge in the forum. We are already on the lookout for the Tip of February!
Graphisoft Community Team
