Saturday, December 28, 2013

Property Lines without Digital Reference

As a follow up to a related post last week this post describes how we can create a property line when we lack any digital data to use. The survey may be an old hand drawn document provided as part of the deed or it could just be a printed drawing that nobody can find the file for. While we wait for a new survey we can still start with what we have. We've captured some bearing and distance information from my old survey drawing.

When we have a CAD file we can import as a resource the Property Line tool option: Create by Sketching makes it pretty easy. Since that's not an option in this situation we need to choose the other option: Create by entering distances and bearing.

Take a moment to revise the project units so they show the same units as the survey data. It helps to confirm the values we see in the dialog match those we've entered (it's shown that way in the image, not in the video). When we enter values for bearing a space between Degrees, Minutes and Seconds is all that's needed. To advance from one field to another we can use the TAB key to move forward or SHIFT + TAB to move backward in the dialog.

Also note that if the distance and bearing information is accurate enough Revit will report "closed". If the data isn't then it won't be able to report "closed" or show the area of the property. Unlike many sketch based elements Revit will tolerate a Property Line boundary that does not close. I altered the distance for the last segment to show the following error message that appears.

Once the Property Line is completed, click OK and we'll find the element is "stuck" to our cursor expecting us to decide where to place it. We pick an arbitrary spot and then move it so a corner of the Property Line is at a corner of the building. The goal is to make it easy to use Rotate True North and define the angle between the current Project North position of the building and the side of the property we'd like it to line up with.

In this example we've decided that the side of the house needs to be parallel to the East property boundary segment. Now we can use Rotate True North. When the tool starts we need to choose where the Rotation origin should go. In this case we need it to be at the corner of the building, the same corner where the corner of the Property Line is now. The first pick is rotation origin, the second pick is on the building and third pick is on the property line segment.

The task is much easier when we put the Property Line right on top of the building as a frame of reference. It also allows us to define the angle without trying to determine what it actually is.

Now that the orientation is correct we can move the Property Line into the correct location/position. Adding dimensions makes it easier to be accurate. We need to double check the values to make sure the changes to one dimensional direction don't alter other dimensions inappropriately.

This is a video demonstration of the concepts with captions, no audio.

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