Chapter 5

Parcels

Land development projects often involve the subdivision of large pieces of land into smaller lots. Even if your projects don't directly involve subdivisions, you're often required to show the legal boundaries of your site and the adjoining sites.

AutoCAD^® Civil 3D^® parcels give you a dynamic way to create, edit, manage, and annotate these legal land divisions. If you edit a parcel segment to make a lot larger, all of the affected labels will update — including areas, bearings, distances, curve information, and table information.

In this chapter, you will learn to:

• Create a boundary parcel from objects
• Create a right-of-way parcel using the right-of-way tool
• Create subdivision lots automatically by layout
• Add multiple-parcel segment labels

Introduction to Sites

In Civil 3D, a site is a collection of parcels, alignments, grading objects, and feature lines that share a common topology. In other words, Civil 3D objects that are in the same site are related to, as well as interact with, one another. The objects that react to one another are called site geometry objects.

The following objects must be placed on a site:

• Feature lines
• Grading groups
• Parcels

Feature lines and grading groups are discussed in depth in Chapter 16, “Grading.” Alignments, discussed in the next chapter, do not need to go on a site.

Think Outside of the Lot

You will want to separate by site any objects you don't want interfering with one another. For example, you may have a set of parcels that represent impervious areas for drainage calculations. In the same location, you may have parcels representing property boundaries. By keeping these items on separate sites, you will be able to keep area information separate.

Dynamic area labels are useful for delineating and analyzing soil boundaries; paving, open space, and wetlands areas; and any other region enclosed with a boundary.

Like all Civil 3D objects, parcels utilize styles. Parcel styles can be used to color-code different parcel types.

It's important to understand how site geometry objects react to one another. Figure 5.1 shows a typical parcel that might represent a property boundary.

Figure 5.1 A typical property boundary

When an alignment is drawn and placed on the same site as the property boundary, the parcel splits into two parcels, as shown in Figure 5.2.

Figure 5.2 An alignment that crosses a parcel divides the parcel in two if the alignment and parcel exist on the same site.

You must plan ahead to create meaningful sites based on interactions between the desired objects. For example, if you want a road centerline, a road right-of-way (ROW) parcel, and the lots in a subdivision to react to one another, they need to be in the same site (see Figure 5.3).

Figure 5.3 Alignments, ROW parcels, open space parcels, and subdivision lots react to one another when drawn on the same site.

The alignment (or road centerline), ROW parcel, and lots all relate to one another. A change in the centerline of the road should prompt a change in the ROW parcel and the subdivision lots.

If you'd like to avoid the interaction between site geometry objects, place them in different sites. Figure 5.4 shows an alignment that has been placed in a different site from the boundary parcel. Notice that the alignment doesn't split the boundary parcel.

Figure 5.4 An alignment that crosses a parcel won't interact with the parcel if they exist on different sites.

It's important that only objects that are intended to react to each other be placed in the same site. For example, in Figure 5.5 you can see parcels representing both subdivision lots and soil boundaries. Because it wouldn't be meaningful for a soil boundary parcel segment to interrupt the area or react to a subdivision lot parcel, the subdivision lot parcels have been placed in a Subdivision Lots site, and the soil boundaries have been placed in a Soil Boundaries site.

Figure 5.5 Parcels can be used for subdivision lots and soil boundaries as long as they're kept in separate sites.

If you didn't realize the importance of site topology, you might create both your subdivision lot parcels and your soil boundary parcels in the same site and find that your drawing looks similar to Figure 5.6. This figure shows the soil boundary segments dividing and interacting with subdivision lot parcel segments, which doesn't make any sense.

Figure 5.6 Subdivision lots and soil boundaries react inappropriately when placed in the same site.

Another way to avoid site geometry problems is to do site-specific tasks in different drawings and use a combination of external references and data references to share information. For example, you could have an existing base drawing that housed the Soil Boundaries site, XRef'd into a subdivision plat drawing that housed the Subdivision Lots site instead of separating the two drawings onto two different sites.

You should consider keeping your legal site plan in its own drawing. Because of the interactive and dynamic nature of Civil 3D parcels, it might be easy to accidentally grab a parcel segment when you meant to grab a manhole, and unintentionally edit a portion of your plat.

You'll see additional examples and drawing divisions later in this chapter, as well as in Chapter 18, “Advanced Workflows.”

If you decide to have sites in the same drawing, here are some sites you may want to create. These suggestions are meant to be used as a starting point. Use them to help find a combination of sites that works for your projects:

As you learn new ways to take advantage of alignments, parcels, and grading objects, you may find additional sites that you'd like to create at the beginning of a new project.

What about the “Siteless” Alignment?

As mentioned earlier in this chapter, you have a choice whether or not to place your alignments on a site. There are many situations where having the alignment independent from other objects is desirable, and therefore the <none> site can be used.

However, you can still create alignments in traditional sites, if you desire, and they will react to other site geometry objects. For example, if you wish to use the Create Right Of Way tool, the alignment you are working with must be on the same site as the main parcel.

You'll likely find that best practices for most alignments are to place them in the <none> site. For example, if road centerlines, road transition alignments, swale centerlines, and pipe network alignments are placed in the <none> site, you'll save yourself quite a bit of site geometry management.

If you decide you'd like to move the alignment to a site or to <none>, you can do so at any time. Click the alignment you wish to reassign. On the Alignment contextual tab ⇒ Modify panel flyout, click Move To Site. See Chapter 6, “Alignments,” for more information about alignments.

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Creating a New Site

You can create a new site in Prospector. You'll find the process easier if you brainstorm potentially needed sites at the beginning of your project and create those sites right away — or, better yet, save them as part of your standard Civil 3D template. You can always add or delete sites later in the project.

The Sites collection is stored in Prospector, along with the other Civil 3D objects in your drawing.

The following exercise will lead you through creating a new site that you can use for creating subdivision lots:

1. Open the CreateSite.dwg (CreateSite_METRIC.dwg) file, which you can download from this book's web page at www.sybex.com/go/masteringcivil3d2013.

Note that the drawing contains alignments and a boundary parcel, as shown in Figure 5.7.

Figure 5.7 The Create Site drawing contains alignments and a boundary parcel.

2. On the Prospector tab of Toolspace, go to Sites.

3. Right-click the Sites collection, and select New to open the Site Properties dialog.

4. On the Information tab of the Site Properties dialog, enter Subdivision Lots for the name of your site.

5. Confirm that the settings on the 3D Geometry tab match what is shown on Figure 5.8.

Figure 5.8 Confirm the settings on the 3D Geometry tab.

As you create parcels, Civil 3D will automatically number them for you. The values in the Numbering tab are the starting point.

6. Confirm that both values on the Numbering tab are set to 1. Click OK.

7. Locate the Sites collection on the Prospector tab of Toolspace, and note that your Subdivision Lots site appears on the list, as shown in Figure 5.9. You can repeat the process for all the sites you anticipate needing over the course of the project.

Figure 5.9 Your new site is listed in Prospector.

Creating a Boundary Parcel

The Create Parcel From Objects tool allows you to create parcels by choosing AutoCAD entities in your drawing or in an XRef'd drawing. In a typical workflow, it's common to encounter a boundary created by AutoCAD entities, such as polylines, lines, and arcs.

When you're using AutoCAD geometry to create parcels, it's important that the geometry be created carefully and meet certain requirements. The AutoCAD geometry must be lines, arcs, polylines, 3D polylines, or polygons. It can't include blocks, ellipses, circles, or other entities. Civil 3D may allow you to pick objects with an elevation other than zero, but you'll find you get better results if you flatten the objects so all objects have an elevation of zero. Sometimes the geometry appears sound when elevation is applied, but you may notice this isn't the case once the objects are flattened. Flattening all objects before creating parcels can help you prevent frustration when creating parcels.

This exercise will teach you how to create a parcel from Civil 3D objects:

1. Open the CreateBoundaryParcel.dwg (CreateBoundaryParcel_METRIC.dwg) file, which you can download from this book's web page.

This drawing has several alignments, which were created on the Proposed site, and some AutoCAD lines representing a boundary. A parcel automatically formed on the site because the alignments form a closed area.

2. On the Home tab ⇒ Create Design panel, select Parcel ⇒ Choose Create Parcel From Objects.

3. At the Select lines, arcs, or polylines to convert into parcels or [Xref]: prompt, pick the red lines that represent the site boundary, and press .

The Create Parcels – From Objects dialog appears.

4. From the drop-down menus, select Proposed; Lot (Prop); and Name Square Foot & Acres (or Name Square Meter & Ha if you are working in metric units) in the Site, Parcel Style, and Area Label Style selection boxes, respectively.

Leave everything else set to the defaults, as shown in Figure 5.10.

Figure 5.10 Site and Style settings for your new boundary parcel

5. Click OK to dismiss the dialog.

The boundary polyline forms parcel segments that react with the alignments. Area labels are placed at the newly created parcel centroids, as shown in Figure 5.11.

Figure 5.11 The boundary parcel segments, alignments, and area labels

Using Parcel Creation Tools

When you don't have existing lines to work with, the best option is to draw parcel segments using the Parcel Layout tools. Figure 5.12 shows the many commands available to you.

Figure 5.12 Selecting Parcel Creation Tools

Although you may never have thought of things like wetland areas or easements as parcels in the past, you can take advantage of the parcel tools to assist in labeling, stylizing, and analyzing these features for your plans.

This exercise will teach you how to create a parcel representing wetlands using the transparent commands and Draw Tangent-Tangent With No Curves tool from the Parcel Layout Tools toolbox:

1. Open the WetlandsParcel.dwg (WetlandsParcel_METRIC.dwg) file, which you can download from this book's web page.

Note that this drawing has several alignments, parcels, and a series of points that represent a wetlands delineation.

2. Choose Parcel ⇒ Parcel Creation Tools on the Create Design panel.

The Parcel Layout Tools toolbar appears.

3. Click the Draw Tangent-Tangent With No Curves tool on the Parcel Layout Tools toolbar.

The Create Parcels – Layout dialog appears.

4. From the drop-down menus, select Proposed; Wetland; and Name Square Foot & Acres (or Name Square Meters & HA) in the Site, Parcel Style, and Area Label Style selection boxes, respectively.

Keep the default settings for all other options.

5. Click OK.

6. At the Specify start point: prompt, click the Point Number Transparent Command.

7. At the Enter Point Number: prompt, enter 1-6 .

You will see a line form through the wetland boundary points in the northwest corner of the project, and immediately form the parcel.

8. Press Esc once to exit the Transparent Command, and press Esc a second time to complete the parcel.

9. Repeat steps 3–8 for the other wetland points near the south of the project using points 7–18.

10. Press Esc twice to exit the command.

Your drawing should look similar to Figure 5.13.

Figure 5.13 The wetlands defined on the site

To illustrate how to change the styles that are in use on a parcel, you will next change the parcel style and the area selection label style.

11. Select the parcel's area label. From the Parcel contextual tab ⇒ Modify panel, click Parcel Properties.

The Parcel Properties dialog appears.

12. On the Information tab, select Mitigated Wetland from the drop-down menu in the Object Style selection box, and then click Apply to observe the change.

Remain in the Parcel Properties dialog. The parcel hatch pattern will turn blue and only be applied to the perimeter of the parcel.

13. To change the parcel area label style, switch to the Composition tab in Parcel Properties.

14. From the Area Selection Label Style pull-down, select Wetland Area Label, and click OK.

15. Change the Area Selection Label Style setting for the wetland parcel to the south.

16. Select the parcel by clicking on its area label, and click Parcel Properties from the Parcel contextual tab as you did in step 14.

17. In the Composition tab, change the Area Selection Label Style setting to Wetland Area Label and click OK.

Your parcels will look like Figure 5.14.

Figure 5.14 The wetlands parcel with the appropriate label styles applied

Creating a Right-of-Way Parcel

The Create ROW tool creates ROW parcels on either side of an alignment based on your specifications. The Create ROW tool can be used only when alignments are placed on the same site as the boundary parcel. The resulting ROW parcel will look similar to Figure 5.15.

Figure 5.15 The resulting parcels after application of the Create ROW tool

Options for the Create ROW tool include:

• Offset distance from alignment
• Fillet or chamfer cleanup at parcel boundaries
• Alignment intersections

Figure 5.16 shows an example of chamfered cleanup at alignment intersections.

Figure 5.16 A ROW with chamfer cleanup at alignment intersections

Once the ROW parcel is created, it's no different from any other parcel. For example, it doesn't maintain a dynamic relationship with the alignment that created it. A change to the alignment will require the ROW parcel to be edited or, more likely, re-created.

This exercise will teach you how to use the Create ROW tool to automatically place a ROW parcel for each alignment on your site:

1. Open the CreateROWParcel.dwg (CreateROWPARCEL_METRIC.dwg) file, which you can download from this book's web page.

Note that this drawing has some alignments on the same site as the boundary parcel, resulting in several smaller parcels between the alignments and boundary.

2. On the Home tab ⇒ Create Design panel, choose Parcel ⇒ Create Right Of Way.

3. At the Select parcels: prompt, pick EX LOT 1, EX LOT 2, and EX LOT 3 on the screen.

4. Press to stop picking parcels.

The Create Right Of Way dialog appears, as shown in Figure 5.17.

Figure 5.17 The Create Right Of Way dialog

5. Expand the Create Parcel Right of Way parameter, and enter 25′ (8 m) as the value for Offset From Alignment.

6. Expand the Cleanup At Parcel Boundaries parameter.

7. Enter 25′ (8 m) as the value for Fillet Radius At Parcel Boundary Intersections.

8. Select Fillet from the drop-down menu in the Cleanup Method selection box.

9. Expand the Cleanup At Alignment Intersections parameter.

10. Enter 35′ (10 m) as the value for Fillet Radius At Alignment Intersections.

11. Select Fillet from the drop-down menu in the Cleanup Method selection box.

12. Click OK to dismiss the dialog and create the ROW parcels.

Your drawing should look similar to Figure 5.18.

Figure 5.18 The completed ROW parcels

Adding a Cul-de-Sac Parcel

If you look at your drawing, on the lower-left side of your right of way it looks incomplete. You will add a cul-de-sac here. Rather than go through all the mechanics of a cul-de-sac, a block has been created for you and you will insert it and turn it into a parcel. This section also introduces some editing tools.

You will need to have completed the previous exercise before continuing or open the “FINISHED” version of the drawing.

1. Continue working in the drawing from the previous exercise.

2. Insert the CulDeSacBlock.dwg (CulDeSacBlock_METRIC.dwg) file using the settings shown in Figure 5.19.

Figure 5.19 Inserting the cul-de-sac block settings

3. From the Home tab ⇒ Create Design panel, expand Parcel ⇒ Create Parcel From Objects.

4. At the Select lines, arcs, or polylines to convert into parcels or [Xref]: prompt, draw a window around all of the cul-de-sac objects, and press .

5. In the Create Parcels – From Objects dialog, make sure that:

• Site is set to Subdivision Lots
• Parcel Style is set to Property
• Area Label Style is set to Name Square Foot & Acres (Name Square Meter & HA)
• Erase Existing Entities is checked

6. Click OK.

Your drawing should look like Figure 5.20.

Figure 5.20 The cul-de-sac turned into a parcel

The cul-de-sac is now a parcel, but there are some extra lines that need to be taken care of. Let's see how to clean this up a bit.

7. From the Home tab ⇒ Create Design panel ⇒ Parcel, select Parcel Creation Tools.

The Parcel Layout Tools palette opens.

8. Select the Delete Sub-Entity tool.

9. At the Select subentity to remove: prompt, select the right of way that interferes with the cul-de-sac, as shown in Figure 5.21.

Figure 5.21 Delete these portions.

10. Press Esc twice to exit the command.

Your cul-de-sac is complete, as shown on Figure 5.22.

Figure 5.22 The finished cul-de-sac

Creating Subdivision Lot Parcels Using Precise Sizing Tools

The precise sizing tools allow you to create parcels to your exact specifications. You'll find these tools most useful when you have your roadways established and understand your lot-depth requirements. These tools provide automatic, semiautomatic, and freeform ways to control frontage, parcel area, and segment direction.

Attached Parcel Segments

Parcel segments created with the precise sizing tools are called attached segments. Attached parcel segments have a start point that is attached to a frontage segment and an endpoint that is defined by the next parcel segment they encounter. Attached segments can be identified by their distinctive diamond-shaped grip at their start point and no grip at their endpoint (see Figure 5.23).

Figure 5.23 A series of attached parcel segments, with their endpoints at the front lot line

In other words, you establish their start point and their direction, but they seek another parcel segment to establish their endpoint. Figure 5.23 shows a series of attached parcel segments. You can tell the difference between their start and endpoints because the start points have the diamond-shaped grips.

You can drag the diamond-shaped grip along the frontage to a new location, and the parcel segment will maintain its angle from the frontage. If the rear lot line is moved or erased, the attached parcel segments find a new endpoint (see Figure 5.24) at the next available parcel segment.

Figure 5.24 The endpoints of attached parcel segments extend to the next available parcel segment if the initial parcel segment is erased.

Precise Sizing Settings

The precise sizing tools consist of the Slide Angle, Slide Direction, and Swing Line tools (see Figure 5.25).

Figure 5.25 Helpful parcel segment creation tools on the Parcel Layout Tools toolbar

The Parcel Layout Tools toolbar can be expanded so that you can establish settings for each of the precise sizing tools (see Figure 5.26). Each of these settings is discussed in detail in the following sections.

Figure 5.26 Automated sizing options on the expanded Parcel Layout Tools toolbar

New Parcel Sizing

When you create new parcels, the tools respect your default area and minimum frontage (measured from either a ROW or a building setback line). The program always uses these numbers as a minimum; it bases the actual lot size on a combination of the geometry constraints (lot depth, frontage curves, and so on) and the additional settings that follow. Keep in mind that the numbers you establish under the New Parcel Sizing option must make geometric sense. For example, if you'd like a series of 7,500 square foot (700 square meter) lots that have 100′ (30 m) of frontage, you must make sure that your rear parcel segment allows for at least 75′ (23 m) of depth; otherwise, you may wind up with much larger frontage values than you desire or a situation where the software can't return a meaningful result.

Automatic Layout

Automatic Layout has two parameters when the list is expanded: Automatic Mode and Remainder Distribution. The Automatic Mode parameter can have the following values:

The Remainder Distribution parameter tells Civil 3D how you'd like “extra” land handled. This parameter has the following options:

There aren't any rules per se in a typical subdivision workflow. Typically the goal is to create as many parcels as possible within the limits of available land. To that end, you'll use a combination of AutoCAD tools and Civil 3D tools to divide and conquer the particular tract of land with which you are working.

Slide Line – Create Tool

The Slide Line – Create tool creates an attached parcel segment based on an angle from frontage. You may find this tool most useful when your jurisdiction requires a uniform lot-line angle from the right of way.

This exercise will lead you through using the Slide Line – Create tool to create a series of subdivision lots:

1. Open the CreateSubdivisionLots.dwg (CreateSubdivisionLots_METRIC.dwg) file, which you can download from this book's web page.

Note that this drawing has several alignments on the same site as the boundary parcel, resulting in several smaller parcels between the alignments and boundary.

2. Choose Parcel ⇒ Parcel Creation Tools on the Create Design panel. The Parcel Layout Tools toolbar appears.

3. Expand the toolbar by clicking the Expand The Toolbar button.

4. In the Parcel Sizing section, change the value of the following parameters by clicking in the Value column and typing in the new values if they aren't already set. Notice how the preview window changes to accommodate your preferences:

• Minimum Area: 7500.00 sq. ft. (700 m²)
• Minimum Frontage: 75.000′ (25 m)
• Use Minimum Frontage At Offset: Yes
• Frontage Offset: 25.000′ (10 m)
• Minimum Width: 75.000′ (25 m)
• Minimum Depth: 50.000′ (15 m)
• Use Maximum Depth: No
• Maximum Depth: (leave default value as this will not be used)
• Multiple Solution Preference: Use shortest frontage

5. In the Automatic Layout section, change the following parameters by clicking in the Value column and selecting the appropriate option from the drop-down menu, if they aren't already set:

• Automatic Mode: On
• Remainder Distribution: Redistribute remainder

6. Click the Slide Line – Create tool. The Create Parcels – Layout dialog appears.

7. From the drop-down menus, select Subdivision Lots; Lot (Prop); and Name Square Foot & Acres (Name Square Meter & HA) in the Site, Parcel Style, and Area Label Style selection boxes, respectively.

Leave the rest of the options set to their defaults.

8. Click OK to dismiss the dialog.

9. At the Select parcel to be subdivided or [Pick]: prompt, click the EX LOT 1 area label.

10. At the Select start point on frontage: prompt, use your Endpoint Osnap to pick the point of curvature along the ROW parcel segment for Property 1 (see Figure 5.27).

Figure 5.27 Pick the point of curvature along the ROW parcel segment.

The parcel jig appears.

11. Move your mouse slowly along the ROW parcel segment, and notice that the parcel jig follows the parcel segment.

12. At the Select end point on frontage: prompt, use your Endpoint Osnap to pick the point of curvature along the ROW parcel segment for Property 1 (see Figure 5.28).

Figure 5.28 Allow the parcel-creation jig to follow the parcel segment, and then pick the point of curvature along the ROW parcel segment.

13. At the Specify angle or [Bearing/aZimuth]: prompt, enter 90 .

Notice the preview (see Figure 5.29).

Figure 5.29 A preview of the results of the automatic parcel layout

14. At the Accept result? [Yes/No] <Yes>: prompt, press to accept the default Yes.

15. At the Select parcel to be subdivided or [Pick]: prompt, press .

16. Click the X to close the Parcel Layout Tools toolbar.

Your drawing should look similar to Figure 5.30.

Figure 5.30 The automatically created lots

The parcels at the north end just don't look right. We'll address that in the next section of this chapter.

Curves and the Frontage Offset

In most cases, the frontage along a building setback is graphically represented as a straight line behind the setback. When you specify a minimum width along a frontage offset (the building setback line) in the Parcel Layout Tools dialog, and when the lot frontage is curved, the distance you enter is measured along the curve, as shown by the dashed line here.

In most cases, this result may be insignificant, but in a large development, the error could be the defining factor in your decision to add or subtract a parcel from the development.

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Swing Line – Create Tool

The Swing Line – Create tool creates a “backward” attached parcel segment where the diamond-shaped grip appears not at the frontage but at a different location that you specify. The tool respects your minimum frontage, and it adjusts the frontage so it is larger, if necessary, in order to respect your default area. The Swing Line – Create tool is semiautomatic because it requires your input of the swing point location.

You may find this tool most useful around a cul-de-sac or in odd-shaped corners where you must hold frontage but have a lot of flexibility in the rear of the lot.

Using the Free Form Create Tool

A site plan is more than just single-family lots. Areas are usually dedicated for open space, stormwater-management facilities, parks, and public utility lots. The Free Form Create tool can be useful when you're creating these types of parcels. This tool, like the precise sizing tools, creates an attached parcel segment with the special diamond-shaped grips.

In the following exercise, you'll use the Free Form Create tool to create a new parcel:

1. Open the CreateFreeForm.dwg (CreateFreeForm_METRIC.dwg) file.

Note that this drawing contains a series of subdivision lots.

2. Pan over to EX LOT 20.

You can see the lot line that was drawn automatically in the previous exercise that obviously will not work (Figure 5.31).

Figure 5.31 Delete the highlighted parcel line.

3. Delete the parcel line highlighted in Figure 5.31.

The parcels readjust but the resulting lot is now much larger than needed. Let's add a line using the Free Form Create tool. You will explore deleting parcel lines in more depth later in this chapter.

4. Select Parcel ⇒ Parcel Creation Tools on the Create Design panel, and select the Free Form Create tool.

The Create Parcels – Layout dialog appears.

5. Select Subdivision Lots; Lot (Prop); and Name Square Foot & Acres (Name Square Meters & HA) from the drop-down menus in the Site, Parcel Style, and Area Label Style selection boxes, respectively.

Keep the default values for the remaining options.

6. Click OK to dismiss the dialog.

7. Slide the Free Form Create attachment point around the Lot: 20 area (your lot number may differ).

8. At the Select attachment point: prompt, use your Endpoint Osnap to pick the endpoint, as shown in Figure 5.32.

Figure 5.32 Use the Free Form Create tool to select an attachment point.

9. At the Specify lot line direction:(ENTER for perpendicular) or [Bearing/aZimuth]: prompt, press to specify a perpendicular lot line direction.

A new parcel segment is created perpendicular to the ROW parcel segment, as shown in Figure 5.33 (your resulting lot numbers may differ). Note that a new lot parcel has formed.

Figure 5.33 Attach the parcel segment to the marker point provided.

10. Press to exit the Free Form Create command.

11. Click the X or press Esc to exit the Parcel Layout Tools toolbar.

12. Pick the new parcel segment so that you see its diamond-shaped grip.

13. Grab the grip, and slide the segment along the ROW parcel segment (see Figure 5.34).

Figure 5.34 Sliding an attached parcel segment

Notice that when you place the parcel segment at a new location, the segment endpoint snaps back to the rear parcel segment. This is typical behavior for an attached parcel segment.

Editing Parcels by Deleting Parcel Segments

One of the most powerful aspects of Civil 3D parcels is the ability to perform many iterations of a site plan design. Typically, this design process involves creating a series of parcels and then deleting them to make room for iteration with different parameters, or deleting certain segments to make room for easements, public utility lots, and more.

You can delete parcel segments using the AutoCAD Erase tool as shown in the previous exercise, or the Delete Sub-Entity tool on the Parcel Layout Tools toolbar.

It's important to understand the difference between these two methods. The AutoCAD Erase tool behaves as follows:

• If the parcel segment was originally created from a polyline (or similar parcel layout tools, such as the Tangent-Tangent With No Curves tool), the AutoCAD Erase tool erases the entire segment (see Figure 5.35).

Figure 5.35 The segments indicated by the blue grips will be erased after using the AutoCAD Erase tool.

• If the parcel segment was originally created from a line or arc (or similar parcel layout tools, such as the precise sizing tools), then AutoCAD Erase erases the entire length of the original line or arc (see Figure 5.36).

Figure 5.36 The AutoCAD Erase tool will erase the entire segment indicated by the blue grips.

The Delete Sub-Entity tool acts more like the AutoCAD Trim tool. The Delete Sub-Entity tool only erases the parcel segments between parcel vertices. For example, if Lot 26, as shown in Figure 5.37, must be absorbed into Lot 3 to create a public utility easement, you'd want to only erase the segment at the rear of Lot 26 and not the entire segment shown previously in Figure 5.36.

Figure 5.37 Use the Delete Sub-Entity tool to erase the rear parcel segment for Lot 26.

As an alternate to launching from the Home tab ⇒ Create Ground Data panel ⇒ Parcel ⇒ Parcel Creation tools, you can access the Parcel Creation tools by selecting a lot label. From the Parcel contextual tab ⇒ Modify panel, select Parcel Layout Tools. Selecting the Delete Sub-Entity tool allows you to pick only the small rear parcel segment for Lot 26. Figure 5.38 shows the result of this deletion.

Figure 5.38 The rear lot line for Lot 26 was erased using the Delete Sub-Entity tool, thus creating a larger Lot 3.

The following exercise will lead you through deleting a series of parcel segments using both the AutoCAD Erase tool and the Delete Sub-Entity tool:

1. Open the DeleteSegments.dwg (DeleteSegments_Metric.dwg) file.

Note that this drawing contains a series of subdivision lots, along with a wetlands boundary.

Let's say you just received word that you are allowed to build on the wetland area.

2. Use the AutoCAD Erase tool to erase the parcel segments that define the wetlands parcel and then freeze the wetlands points.

Note that the entire parcel disappears as soon as the first segment is removed, causing a “hole” in the parcel.

Now the developer has decided to enlarge the lots.

3. Erase the lot lines, as shown in Figure 5.39.

Figure 5.39 The parcel lines to be deleted

After deleting parcel segments, your lots should look similar to Figure 5.40.

Figure 5.40 The re-created lots

Next, you discover that Lot 26 needs to be removed and absorbed into Lot 3.

4. From the Parcel Layout Tools toolbar, click the Delete Sub-Entity tool.

5. At the Select subentity to remove: prompt, pick the rear lot line of the newly combined Lot 26.

6. Press to exit the command and then click the X to exit the Parcel Layout Tools toolbar.

The resulting parcel is shown in Figure 5.41.

Figure 5.41 The parcel after erasing the rear lot line

Best Practices for Parcel Creation

Now that you have an understanding of how objects in a site interact and you've had some practice creating and editing parcels in a variety of ways, we'll take a deeper look at how parcels must be constructed to achieve topology stability, predictable labeling, and desired parcel interaction.

Forming Parcels from Segments

Earlier in this chapter, you saw that parcels are created only when parcel segments form a closed area (see Figure 5.42).

Figure 5.42 A parcel is created when parcel segments form a closed area.

Parcels must always close. Whether you draw AutoCAD lines and use the Create Parcel From Objects menu command or use the parcel segment creation tools, a parcel won't form until there is an enclosed polygon. Figure 5.43 shows four parcel segments that don't close; therefore, no parcel has been formed.

Figure 5.43 No parcel will be formed if parcel segments don't completely enclose an area.

There are times in surveying and engineering when parcels of land don't necessarily close when created from legal descriptions. In this case, you must work with your surveyor to perform an adjustment or find some other solution to create a closed polygon.

You also saw that even though parcels can't be erased, if you erase the appropriate parcel segments, the area contained within a parcel is assimilated into neighboring parcels.

Parcels Reacting to Site Objects

Parcels require only one parcel segment to divide them from their neighbor (see Figure 5.44). This behavior eliminates the need for duplicate segments between parcels, and duplicate segments must be avoided.

Figure 5.44 Two parcels, with one parcel segment between them

As you saw in the section on site interaction, parcels understand their relationships to one another. When you create a single parcel segment between two subdivision lots, you have the ability to move one line and affect two parcels. Figure 5.45 shows the moved parcel segment from Figure 5.44 once the parcel segment between them has been shifted to the left. Note that both areas change in response.

Figure 5.45 Moving one parcel segment affects the area of two parcels.

A mistake that many people new to Civil 3D make is to create parcels from closed polylines, which results in a duplicate segment between parcels. Figure 5.46 shows two parcels created from two closed polylines. These two parcels may appear identical to the two seen in the previous example, because they were both created from a closed polyline rectangle; however, the segment between them is actually two segments.

Figure 5.46 Adjacent parcels created from closed polylines create overlapping or duplicate segments.

The duplicate segment becomes apparent when you attempt to grip-edit the parcel segments. Moving one vertex from the common lot line, as seen in Figure 5.47, reveals the second segment. Also note that a sliver parcel is formed. Duplicate site geometry objects and sliver parcels make it difficult for Civil 3D to solve the site topology and can cause unexpected parcel behavior.

Figure 5.47 Duplicate segments become apparent when they're grip-edited and a sliver parcel is formed.

Creating a subdivision plat of parcels this way almost guarantees that your labeling won't perform properly and could lead to inaccurate data.

Parcels form to fill the space contained by the original outer boundary. You should always begin a parcel-division project with an outer boundary of some sort (see Figure 5.48).

Figure 5.48 An outer boundary parcel

You can then add road centerline alignments to the site, which divides the outer boundary, as shown in Figure 5.49.

Figure 5.49 Alignments added to the same site as the boundary parcel divide the boundary parcel.

It's important to note that the boundary parcel no longer exists intact. As you subdivide this site, Parcel 1 is continually reallocated with every division. As road ROW and subdivision lots are formed from parcel segments, more parcels are created. Every bit of space that was contained in the original outer boundary is accounted for in the mesh of newly formed parcels (see Figure 5.50).

Figure 5.50 The total area of parcels contained within the original boundary sums to equal the original boundary area.

From now on, you'll consider ROW, wetlands, parkland, and open space areas as parcels, even if you didn't before. You can make custom label styles to annotate these parcels however you like, including a “no show” or none label.

Overkill Is Just Right for Parcels

Frequently, parcel data comes from GIS sources or from existing plats. The quality of this data can vary, making a direct conversion to Civil 3D parcels difficult.

An excellent tool for ensuring that the conversion of these lines, arcs, and polylines goes smoothly is the Overkill command. Overkill is a base AutoCAD command that will clean up drawings based on the options and tolerance that you choose.

Find the Overkill command on the Home tab ⇒ Modify panel flyout.

Once you have selected the objects you want the Overkill command to analyze, you are prompted to choose how dramatic of a cleanup you want. The default settings, shown here, are rather conservative.

The tolerance determines how close two lines can be before they are considered to be duplicates. The higher this value, the more overlap and duplicates the command will find.

The check boxes indicate properties Overkill will disregard when performing its edits. With all of the check boxes clear, the objects are not considered duplicates unless all of the listed properties match.

Before running the Overkill command, a selected batch of lines slated to become parcels show many extraneous vertices. The plus signs next to the grips indicate where multiple grips overlap.

After you run the Overkill command, the selection shows fewer visible grips and no indication that there are overlapping objects.

As you can see, the Overkill command can save you valuable time cleaning up drawings.

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Constructing Parcel Segments with the Appropriate Vertices

Parcel segments should have natural vertices only where necessary and split-created vertices at all other intersections. A natural vertex, or point of intersection (PI), can be identified by picking a line, polyline, or parcel segment and noting the location of the grips (see Figure 5.51).

Figure 5.51 Natural vertices on a parcel segment

A split-created vertex occurs when two parcel segments touch or cross each other. Note that in Figure 5.52, the parcel segment doesn't show a grip even where each individual lot line touches the ROW parcel.

Figure 5.52 Split-created vertices on a parcel segment

It's desirable to have as few natural vertices as possible. In the example shown in Figure 5.52, the ROW frontage line can be expressed as a single bearing and length from the end of the arc through the beginning of the next arc, as opposed to having several smaller line segments.

If the foundation geometry was drawn with a natural vertex at each lot line intersection, the resulting parcel segment won't label properly and may cause complications with editing and other functions. This subject will be discussed in more detail in the section “Labeling Spanning Segments,” later in this chapter.

Parcel segments must not overhang. Spanning labels are designed to overlook the location of intersection-formed (or T-shaped) split-created vertices. However, these labels won't span a crossing-formed (X- or + [plus]-shaped) split-created vertex. Even a very small parcel segment overhang will prevent a spanning label from working and may even affect the area computation for adjacent parcels. The overhanging segment in Figure 5.53 would prevent a label from returning the full spanning length of the ROW segment it crosses.

Figure 5.53 Overhanging segment

Labeling Parcel Areas

A parcel area label is placed at the parcel centroid by default, and it refers to the parcel in its entirety. When asked to pick a parcel, you pick the area label. An area label doesn't necessarily have to include the actual area of the parcel.

Area labels can be customized to suit your fancy. Figure 5.54 shows a variety of customized area labels.

Figure 5.54 Sample area labels

Area labels often include the parcel name or number. After selecting a parcel, on the Parcel contextual tab ⇒ Modify panel choose Renumber/Rename.

The following exercise will teach you how to renumber a series of parcels:

1. Open ChangeAreaLabel.dwg (ChangeAreaLabel_METRIC.dwg). Note that this drawing contains many subdivision lot parcels.

2. Near the southeast corner of the project, select Lot 25. On the Parcel contextual tab ⇒ Modify panel, select Renumber/Rename. The Renumber/Rename Parcels dialog appears.

3. In the Renumber/Rename Parcels dialog, make sure Subdivision Lots is selected from the drop-down menu in the Site selection box. Change the value of the Starting Number selection box to 1. Click OK.

4. At the Specify start point or [Polylines/Site]: prompt, pick a point on the screen anywhere inside the Lot 25 parcel, which will become your new Lot 1 parcel at the end of the command.

5. At the End point or [Undo]: prompt, pick a point on the screen anywhere inside the Lot 35 parcel, almost as if you were drawing a line; then pick a point inside Lot 39. Press to complete choosing parcels. Press again to end the command.

Note that your parcels have been renumbered from 1 through 15. Repeat the exercise with other parcels in the drawing for additional practice if desired.

The next exercise will lead you through one method of changing an area label using the Edit Parcel Properties dialog:

1. Continue working in the ChangeAreaLabel.dwg (ChangeAreaLabel_METRIC.dwg) file.

2. Select Parcel 1 and select Multiple Parcel Properties from the Modify panel.

3. At the Specify start point or [Polylines/All/Site]: prompt, pick a point on the screen anywhere inside Parcel 1.

4. At the End point or [Undo]: prompt, pick a point on the screen anywhere inside Parcel 11, then Parcel 15, using the same technique that you used in step 2 of the previous exercise.

5. Press to complete parcel selection, and press again to open the Edit Parcel Properties dialog.

6. In the Area Selection Label Styles portion of the Edit Parcel Properties dialog, use the drop-down menu to choose the Parcel Number area label style, as shown in Figure 5.55.

Figure 5.55 The Edit Parcel Properties dialog

7. Click the Apply To All Parcels button to the right of the Parcel Number listing.

8. Click Yes in the dialog displaying the question “Apply the area selection label style to the 15 selected parcels?”

9. Click OK to exit the Edit Parcel Properties dialog.

The 15 parcels now have parcel area labels that call out numbers only. Note that you could also use this interface to add a second area label to certain parcels if required.

This section's final exercise will show you how to use Prospector to change a group of parcel area labels at the same time:

1. Continue working in the ChangeAreaLabel.dwg (ChangeAreaLabel_METRIC.dwg) file.

2. In Prospector, expand Sites ⇒ Subdivision Lots and select the Parcels collection.

3. Hold down the Ctrl key, and select all of the lots whose names begin with Lot.

4. Release the Ctrl key, and your parcels should remain selected.

5. Slide over to the Area Label Style column, right-click the column header, and select Edit (see Figure 5.56).

Figure 5.56 Right-click the Area Label Style column header and select Edit.

6. In the Select Label Style dialog, select Parcel Number from the drop-down menu in the Label Style selection box.

7. Click OK to dismiss the dialog.

The drawing will process for a moment.

8. Once the processing is finished, minimize Prospector and inspect your parcels.

All the Single-Family parcels should now have the Parcel Number area label style.

What If the Area Label Needs to Be Split onto Two Layers?

You may have a few different types of plans that show parcels. Because it would be awkward to have to change the parcel area label style before you plot each sheet, it would be best to find a way to make a second label on a second layer so that you can freeze the area component in sheets or viewports when it isn't needed. Here's an example where the square footage has been placed on a different layer so it can be frozen in certain viewports:

You can accomplish this by creating a second parcel area label that calls out the area only:

1. In any drawing containing parcels, change to the Annotate tab.

2. From the Labels & Tables panel, select Add Labels ⇒ Parcel ⇒ Add Parcel Labels.

3. Select Area from the drop-down menu in the Label Type selection box, and then select an area style label that will be the second area label.

4. Click Add, and then pick your parcel on screen.

You'll find a second parcel area label to be a little more automatic when you place it (it already knows what parcel to reference).

You can also use the Multiple Parcel Properties dialog, as shown in the “Editing Parcels by Deleting Parcel Segments” section earlier in the chapter, to add a second label.

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Labeling Parcel Segments

Although parcels are used for much more than just subdivision lots, most parcels you create will probably be used for concept plans, record plats, and other legal subdivision plans. These plans, such as the one shown in Figure 5.57, almost always require segment labels for bearing, distance, direction, crow's feet, and more.

Figure 5.57 A fully labeled site plan

Labeling Multiple-Parcel Segments

The following exercise will teach you how to add labels to multiple-parcel segments:

1. Open the SegmentLabels.dwg (SegmentLabels_METRIC.dwg) file, which you can download from this book's web page.

Note that this drawing contains many subdivision lot parcels.

2. On the Annotate tab ⇒ Labels & Tables panel, click Add Labels.

3. From the drop-down menus in the Add Labels dialog, select Parcel, Multiple Segment, Bearing Over Distance, and Delta Over Length And Radius in the Feature, Label Type, Line Label Style, and Curve Label Style selection boxes, respectively, as shown in Figure 5.58.

Figure 5.58 The Add Labels dialog

4. Click Add.

5. At the Select parcel to be labeled by clicking on area label: prompt, pick the area label for Parcel 1.

6. At the Label direction [CLockwise/COunterclockwise]<CLockwise>: prompt, press to accept the default and again to exit the command.

Each parcel segment for Parcel 1 should now be labeled.

7. Continue picking Parcels 2 through 15 in the same manner.

Note that segments are never given a duplicate label, even along shared lot lines.

8. If time permits, label all of the parcels in the drawing.

9. Press to exit the command. Close the Add Labels dialog.

The following exercise will show you how to edit and delete parcel segment labels:

1. Continue working in the SegmentLabels.dwg (SegmentLabels_METRIC.dwg) file.

2. Zoom in on the label along the frontage of Parcel 8.

3. Select the label.

You'll know your label has been picked when you see a diamond-shaped grip at the label midpoint (see Figure 5.59).

Figure 5.59 A diamond-shaped grip appears when the label has been picked.

4. On the Parcel Segment Label contextual tab ⇒ Modify panel, click Flip Label, as shown in Figure 5.60.

Figure 5.60 The Parcel Segment Label contextual tab

The label flips so that the bearing component is on top of the line and the distance component is underneath the line.

5. Select the label again. On the Parcel Segment Label contextual tab ⇒ Modify panel, click Reverse.

The label reverses so that the bearing now reads SE instead of NW.

6. Repeat steps 3 through 5 for several other segment labels, and note their reactions.

7. Select any label, and once the label is picked, execute the AutoCAD Erase tool or press the Delete key.

Note that the label disappears.

8. Erase all the outer parcel labels in preparation for the next exercise.

Labeling Spanning Segments

Spanning labels are used where you need a label that spans the overall length of an outside segment, such as the example in Figure 5.61.

Figure 5.61 A spanning label

Spanning labels require that you use the appropriate vertices, as discussed in detail in the earlier section “Constructing Parcel Segments with the Appropriate Vertices.” Spanning labels have the following requirements:

• Spanning labels can only span across split-created vertices. Natural vertices will interrupt a spanning length.
• Spanning label styles must be composed to span the outside segment.
• Spanning label styles must be composed to attach the desired spanning components (such as length and direction arrow) on the outside segment (as shown previously in Figure 5.61), with perhaps a small offset.

Once you've confirmed that your geometry is sound and your label is properly composed, you're set to span. The following exercise will teach you how to add spanning labels to single-parcel segments:

Adding Curve Tags to Prepare for Table Creation

To keep plans tidy, it is common to show labels that reference a table for curves and lines. Civil 3D parcels provide tools for creating dynamic line and curve tables. You can keep lines and curves together or create separate tables for each.

Parcel segments must be labeled before they can be used to create a table. They can be labeled with any type of label, but you'll likely find it to be best practice to create a tag-only style for segments that will be placed in a table.

The following exercise will show you how to replace curve labels with tag-only labels, and then renumber the tags:

1. Continue working in the SegmentLabels.dwg (SegmentLabels_METRIC.dwg) file.

Note that the labels along tight curves, such as the cul-de-sac, would be better represented as curve tags.

2. Change to the Annotate tab, and select Add Labels ⇒ Parcel ⇒ Add Parcel Labels from the Labels & Tables panel.

The Replace multiple-segment tool only works if the parcel is already labeled. If you did not get a chance to label the parcels in the previous exercise, use the multiple-label segment instead for step 3.

3. From the drop-down menus in the Add Labels dialog, select Replace Multiple Segment, Bearing Over Distance, and Spanning Curve Tag Only in the Label Type, Line Label Style, and Spanning Curve Tag Only selection boxes, respectively.

4. Click Add. At the Select parcel to be labeled by clicking on area label: prompt, pick the area label for Parcel 1.

Note that the line labels for Parcel 1 are reset and the curve labels convert to tags.

5. Repeat step 4 for Parcels 2 through 15.

6. Press to exit the command.

Now that each curve label has been replaced with a tag, it's desirable to have the tag numbers be sequential. The following exercise will show you how to renumber tags:

1. Continue working in the SegmentLabels.dwg (SegmentLabels_METRIC.dwg) file.

2. Zoom into the curve on the upper-left side of Parcel 11 (see Figure 5.62).

Figure 5.62 Curve tags on Parcel 11

Your curve may have a different number from the figure.

3. From the Parcel contextual tab ⇒ Labels & Tables panel, select Renumber Tags.

4. At the Select label to renumber tag or [Settings]: prompt, type S, and then press .

The Table Tag Numbering dialog appears (see Figure 5.63).

Figure 5.63 The Table Tag Numbering dialog

5. Change the value in the Curves Starting Number selection box to 1, and click OK.

6. Click each curve tag in the drawing at the Select label to renumber tag or [Settings]: prompt.

The command line may say Current tag number is being used, press return to skip to next available or [Create duplicate], in which case you should press to skip the used number.

7. When you're finished, press to exit the command.

Creating a Table for Parcel Segments

The following exercise demonstrates how to create a table from curve tags:

1. Continue working in the SegmentLabels.dwg (SegmentLabels_METRIC.dwg) file.

You should have several curves labeled with the Spanning Curve Tag Only label.

2. Select a parcel. From the Parcel contextual tab ⇒ Labels & Tables panel, select Add Curve.

3. In the Table Creation dialog, select Length Radius & Delta from the drop-down menu in the Table Style selection box.

4. In the Select By Label Or Style area of the dialog, click the Apply check box for the Parcel Curve: Spanning Curve Tag Only entry under Label Style Name.

5. Now that the Selection Rule is active for Parcel Curve: Spanning Curve Tag Only, change it to Add Existing And New.

The Add Existing And New option will ensure that the table updates as more labels fitting this criteria are added to the drawing. Keep the default values for the remaining options. The dialog should look like Figure 5.64.

Figure 5.64 The Table Creation dialog

6. Click OK.

7. At the Select upper left corner: prompt, pick a location in your drawing for the table.

A curve table appears, as shown in Figure 5.65.

Figure 5.65 A curve table

The Bottom Line