Unit Count | Arcol Help Center

Summary of how unit calculations work in Arcol

If you explicitly select what your unit is in Arcol we will calculate it accordingly
If you don't explicitly select a unit type, Arcol will calculate unassigned areas by the unit mix (calculated) ratio
These calculations happen at the same time

Units in Arcol are calculated using a unified approach that combines explicitly assigned area types with those that only have a Building Function assigned:

Area Type Assigned — Face counts as 1 unit each.
Area Type Unassigned — Face is divided into units per the Building Function mix (rounding down to the next whole unit).

This means you can model as much or as little detail as you want — explicitly drawn rooms are counted directly, and the rest is filled in automatically.

Unit Counting for explicitly assigned Area Types

For example, if you have explicitly assigned Area Types to all of your faces, your unit count is simply the sum of those faces per type:

14 - 1 Bedroom

2 - 2 Bedroom

1 - 3 Bedroom

1 - Mechanical/Storage

For a total of 18 units

(if you decide to remove the filter for Core in Unit Counts, you’ll get 2 - Core and a Total of 20 units)

Unit Counting for a blend of unassigned and explicitly assigned Area Types

For example, if you have don’t have explicitly assigned Area Types on a floor, your unit count is based on the mix you choose in the Calculated portion of the area types level of the metrics settings menu:

The explicitly assigned Core and Mechanical/Storage will just use the same counting logic the prior example, but for the Residential Building Function without an explicit Area Type, we break it down per the unit mix:

Unit Mix Breakdown

First, we multiply the area of the Residential Building Function by its Efficiency Multiplier from the Building Functions menu. Let’s say 90%.

Residential Building Function Area = 12,889 sf * .90 = ~11,600 sf.

Next, we calculate the average unit size for the Residential Building Function.

Average Unit Size = (.35 * 646 sf) + (.37 * 753 sf) + (.08 * 915sf) + (0 * 0sf) + (.20 * 484sf) = ~674 sf/unit

Then, we divide the area of the Building Function (with efficiency applied) by the Average Unit Size

Residential = 11,600 sf / 674 sf/unit = 17.21 average units

For each Area Type, the percentage of mix is multiplied by the average units and rounded down.

17.21 * .35 = 6.02, 6 - 1 Bedroom

17.21 * .37 = 6.3677, 6 - 2 Bedroom

17.21 * .08 = 1.38, 1 - 3 Bedroom

17.21 * .00 = 0, 0 - Mechanical/Storage

17.21 * .20 = 3.44, 3 - Studio

Efficiency

Efficiency is used to account for cores and corridors when a Building Function is assigned without a specific Area Type assigned. The efficiency input is found at the building function level of the metrics settings menu.

Setting which area types show in the Units section

You may not want to count all area types (for example, you likely don’t care about counts for cores and corridors).

To set which area types are counted:

Hover on the Units section of the metrics sidebar and click the settings button that appears.
Click on the area type names in the menu that appears to toggle them being counted or not. A white dot shows beside areas which are being counted, which in turn will display a unit count in the Units section.