On Center Home | MyOnCenter Portal | REQUEST A DEMO | CONTACT | SALES: 1-866-627-6246
How to Use Search Effectively

Tools Add
Table of Contents

OST 3.94 - 05.03 Area Conditions

Reference Number: AA-00591 Views: 6376 Created: 01/27/2016 07:46 am Last Updated: 10/04/2017 03:50 pm 100 Rating/ 1 Voters

Area Conditions describe objects such as slabs, ceiling tiles, flooring, roofs, and facades that require a measurement for total square footage (or square meters, etc.). An Area condition can even calculate volume for objects such as concrete slabs, poured walls, and landscape fill if you specify a "Thickness".

Area Condition - General Tab

This is basic information about an Area Condition such as thickness, color/pattern and the Quantity results required.

  • The Dimension area includes optional settings for Thickness and Slope
  • Appearance sets the Color and Pattern of an object and a field to set the spacing in a non-solid or non-transparent pattern
  • Results are the quantities to calculate
  • Notes are additional details about this condition such as construction or build notes

  • Thickness - Allows On-Screen Takeoff to calculate Volume. Handy for concrete slabs, insulation and bedding.
  • Slope - Used primarily for roof takeoffs. On-Screen Takeoff takes into account the Rise:Run or Run:Rise. If performing takeoff on an orthographic project (using a 'birds eye' view) use x:12 for slope (Rise:Run), if taking off an area using an elevation plan, use 12:x (Run:Rise) for slope. Only area and volume are adjusted for slope. See below for a chart of Area Slope Conversions conversion factors to convert degrees to Rise:Run.
Appearance Appearance settings determine how objects drawn with the Condition display on the Image Tab and how each Condition looks in the Conditions list, in the Image Legend, and on the Takeoff Tab and Worksheet Tabs. Select a Color, Pattern, and Spacing (see next row).
Spacing Enter a measurement to set the spacing to be used in non-solid and non-transparent patterns. This only affects how the takeoff is displayed and has no bearing on measurement quantities.
Results You can select up to three Results for each Condition. Quantity "1" should be considered required and its default is Area (SF).

(For Quantities 2 and 3 to show on the Worksheet Tab, you must select a valid Quantity 1)

There are two Area results that are special and depend on the Grid as set on the Advanced tab:

  • Tile Count (Average): Calculates the number of tiles based on area and tile size. For example, for an area of 800 SF with a tile size of 8 SF (ex. 2 X 4 Acoustical Tile) results in a tile count of 100.
  • Tile Count (Visible): Calculates the number of tiles based on grid alignment and orientation rather than on area and tile size. While this adds waste to the takeoff, it can be helpful in more accurately projecting labor and material needed if an architect or owner calls for a specific installation of materials.
Notes This field is for whatever notes to include such as how this condition is built or any other information that helps identify this Condition.

Area Condition Results

Results are the totals for all the measurements taken for a particular condition. Results shown in the Condition window are for the current page only. To see the total for all pages, review the Takeoff or Worksheet Tab.

There are several Area Results options available:

The Result selected determines which Units of Measure are available.

Area The surface area of an object drawn with this Condition less the surface area of any backouts but ignoring the area subtractions of any attachments (A)-(BA)
Area (Ignore Backout Areas) The surface area of an object drawn with this Condition without subtracting backouts or the area subtractions of any attachments (A)
Area (Minus Attachments) The surface area of an object drawn with this Condition, less the surface area of any attachments and less the surface area of any backouts (A)-(BA)-(AA)
Perimeter The linear measurement around an object drawn with this Condition (for example, trim or molding around flooring or the forms needed to pour concrete) - includes Backout perimeters but does not include the perimeter of any attachments (L)+(BL)-(AL)
Perimeter (Without Backout Perimeters) The linear measurement around an object drawn with this Condition, not including the perimeter of any Backouts (L)-(BL)
Perimeter (Plus Attachment Perimeters) The linear measurement around an object drawn with this Condition including the perimeter of any attachments (L)+(AL)
Grid Length (Visible) The linear measurement of grid lines within an object drawn with this Condition if Grid property selected - does not include any perimeter (GL)
Tile Count (Average)The Calculated average count of tiles within an object drawn with this Condition expressed as an each count(Square foot of area condition) ÷ (Square foot of tile based on Grid)
Tile Count (Visible) The actual count of tiles adjusted for the grid alignment; counts each partial or complete tile as one whole tile; expressed as an each count Count of visible tiles/partial tiles
Area Counts The number of objects drawn with this Condition on the Current page (cumulative total on the Takeoff and Worksheet Tabs) Count (Area objects)
Volume The amount of mass of an object drawn with this Condition less the volume of any backouts but ignoring the volume subtractions of any attachments(Surface area (sq ft) x Thickness)-(BV)
Volume (Ignore Backout Volume) The amount of mass of an object drawn with this Condition ignoring any Backout volumes and ignoring the volume subtractions of any attachments (V)
Volume (Minus Attachments) The amount of mass of an object drawn with this Condition less the volume of any attachments and less the volume of any backouts. (V)-(AV)-(BV)

Area Condition Properties - Advanced Tab

The Area condition Advanced Tab contains options for rounding, using a Grid, and snapping, as well as display options.

The Measurement field provides a setting for rounding each segment of an area takeoff to the nearest whole number increment.

"Rounding" an Area Condition/takeoff does not round up overall square footage results for the condition/takeoff object, each Segment is rounded, according to how you setup the Condition. It is very important to understand how Rounding area segments works before using this feature as it can dramatically affect takeoff results. See Related articles for detailed information. See the next article for examples of Rounding.

Advanced Properties fields are used to:

  • Setup a Grid for quantifying a tiled or bricked area expanse
  • Display the Condition's Pattern while drawing the takeoff (ON by default, it can be handy to turn this off when taking off a large or complicated area - when "OFF" displays the outline of the area takeoff until the area is 'closed', then the pattern is filled in)
  • Display Dimension - when activated, On-Screen Takeoff places a small label in the center of each area taken off with this condition showing the individual takeoff objects Quantity 1 result
  • Snap to Linear - automatically connects area takeoff to nearby Linear takeoff based on the Position and Tolerance set.

OptionWhat it does/How it is used...
Round Quantity and Round to Select the Round Quantity box to apply this feature and enter a value to which to round each segment taken off using this Condition.
Grid/Tile/Gap Check the Grid box then, type in the size of the tiles. Next, enter the gap between each tile. This creates a grid pattern at the specified size for the area takeoff object. The gap setting controls the thickness of the lines for the grid area - just like an acoustical ceiling grid.
Display Pattern While Drawing When taking off large or complex areas, it is sometimes easier to suppress the display of the actual pattern while drawing the area. Once the area is 'closed' - it fills in with the appropriate fill pattern as set on the General Tab. (checked by default)
Display Dimension

With this box checked, the Quantity 1 result appears in the center of each area takeoff object drawn, as in the example below.

If dimension boxes are too big or too small, adjust the Font Size to reduce the size. See Related articles for information on Adjusting Annotation.

Display Name When checked, a label showing the Condition Name is placed next to each takeoff object drawn in the Image window.
To adjust the Font/Color of the label, select an individual piece of takeoff and the Text Format toolbar displays.
Each label is adjusted separately. Each label is limited to 9 characters, if your Condition Name exceeds 9 characters, it is displayed as "Condition...".
Snap to Linear Put a check mark in the Snap to Linear box and then choose a position and tolerance for the area takeoff. This feature makes drawing area takeoffs much easier - the area takeoff 'snaps to' nearby linear condition so it does not have to be drawn as precisely. This feature makes it easy to auto-fill rectangular rooms. Once a room is already outlined with linear Condition takeoff, double-clicking within that space auto-fills with the selected area Condition.
Position Determines where the perimeter segments of area takeoff locate themselves in relation to the nearest parallel linear object when using "Snap to Linear"
  • Inner Edge - places the area object’s perimeter on the inner most edge of the closest parallel linear takeoff object.
  • Center - places the area object’s perimeter on the center of the closest parallel linear takeoff object.
  • Outer Edge - places the object’s perimeter on the outer most edge of the closest parallel linear object.
Tolerance Set for the distance that the snap to linear feature uses to snap the area takeoff to the linear takeoff. For example, if set to 1' 6", then when area takeoff is drawn within 1' 6" of a linear takeoff object, the area would automatically to the linear takeoff.

Area Slope Conversions

Use the charts below to convert Degree of slope or Percent (Grade) to Rise:Run.

On-Screen Takeoff uses traditional mathematics to calculate slopes. This may not be the same calculation used for a specific industry.

DegreePerecent (%)Ratio (Rise:Run)
0 n/a 0:1
1 1.75 1:57.29
2 3.49 1:28.636
3 5.24 1:19.081
4 6.99 1:14.301
4.7636 8.33 1:12
5 8.75 1:11.43
6 10.51 1:9.5144
7 12.28 1:8.1443
7.125 12.50 1:8
8 14.05 1:7.1154
9 15.84 1: 6.3138
9.4623 16.67 1:6
10 17.63 1: 5.6713
11 19.44 1: 5.1446
11.31 20.00 1:5
12 21.26 1: 4.7046
13 23.09 01:04.3
14 24.93 1: 4.0108
14.036 25.00 1:4
15 26.80 1: 3.7321
16 28.68 1: 3.4874
16.699 30.00 01:03.3
17 30.57 1: 3.2709
18 32.49 1: 3.0777
18.435 33.33 1:3
19 34.43 1: 2.9042
20 36.40 1: 2.7475
21 38.39 01:02.6
21.801 40.00 1:2.5
22 40.40 1: 2.4751
23 42.45 1: 2.3559
24 44.52 1: 2.246
24.228 45.00 1: 2.2222
25 46.63 1: 2.1445
26 48.77 1: 2.0503
26.565 50.00 1:2
27 50.95 1: 1.9626
28 53.17 1: 1.8807
29 55.43 1: 1.804
30 57.74 1: 1.7321
31 60.09 1: 1.6643
32 62.49 1: 1.6003
33 64.94 1: 1.5399
34 67.45 1: 1.4826
35 70.02 1: 1.4281
36 72.65 1: 1.3764
36.87 75.00 1: 1.3333
37 75.36 1: 1.327
38 78.13 1: 1.2799
39 80.98 1: 1.2349
40 83.91 1: 1.1918
41 86.93 1: 1.1504
42 90.04 1: 1.1106
43 93.25 1: 1.0724
44 96.57 1: 1.0355
45 100.00 1:1
90 n/a 1:0

This table shows the Degrees for each Pitch.

12 45
11 42.5
10 40
9 37
8 33.75
7 30.5
6 26.5
5 22.5
4 18.5
3 14
2 9.5
1 4

There are several Websites available to learn more about slope:



These are not On Center Software sites - these links are provided only as a convenience. All information contained on these sites should be independently verified for accuracy. On Center Software does not warrant the information or content.
Before we move on to Count Conditions, we are going to discuss using the "Rounding" option for an Area Condition.

previous article arrow Linear ConditionsUsing the "Rounding" Option for Area takeoff next article arrow

  • There is no feedback for this article.
Info kBase Article Feedback

If you need Technical Support or want to submit a Feature Request, click one of the buttons below, do not use this form.

request support Request Support submit feature request Feature Request


How Does This Article Not Measure Up?

Your full name: Your Email: Your feedback on this article:


Something Wrong with this Article? Let us Know! Copyright 2018 - On Center Software, Inc. All Rights Reserved.
Be sure to rate this article 5 stars if you found it helpful!.