Calculate Quantities: Surface Areas

Calculate Quantities: Surface Areas tool measures surface quantities based on the object geometry. 

Simplebim calculates quantities based on the geometry of objects. Because of this, it doesn’t matter which model author tool was used for creating the models or who made them. Simplebim always calculates the quantities with the same logic in a consistent way. Thus, quantities are comparable between different models and even between different projects. In other words, Simplebim calculates standardized quantities.

Quantities are calculated both for object instances and container objects. For example, a wall can either be an instance with a single geometry or it can be an assembly with several child objects, each of which has its own geometry and thus also its own quantities.

Quantities can be calculated for objects from any object class. So the wall doesn’t have to be modeled as a wall, and you can still calculate the quantity you need for it.

Settings

There are six different tools for calculating quantities. They all share common settings, which you can find in the Calculate Quantities: Dimensions article.

Here are the settings specific to the Calculate Quantities: Surface Areas tool.

Clean Up Side Surfaces

When calculating Area Side Net or Area Side Gross, you may want to clean up the resulting surfaces, which are overlapping. Calculating formwork for footings is a perfect example of this. For example, a pad footing and continuous footing are modeled with separate objects, and they collide with each other, as they should be in the model. If both surfaces from the collision area are calculated, then you get a too big result, because in the production you don’t build the formwork twice in between the objects. So you don’t want to calculate the area in between twice. The Clean Up Side Surfaces option automatically removes duplicate surfaces from these areas.

Quantities

Surface-based measures are areas calculated from a specific set of surfaces of the object’s geometry. Surfaces are flat areas in the geometry separated by hard edges. Usually, the surfaces for a specific calculation are selected based on their direction. The benefit of the surface-based quantities is, that they take into account all the details in the geometry, unlike the shadow-based areas.

As a surveyor, you don’t always want to take into account all the details. For complex geometry, the surfaces that the calculation uses might not be the ones you expect. A good example of this is wall geometry, which has multiple layers in it. Since all the layers are modeled into the geometry, and they are all pointing in the same direction, the surface-based calculation takes them all into account. In this kind of case, we recommend using shadow-based quantities.

Area Bounding Box

Area of the largest side of the object’s bounding box.

The tool finds the smallest bounding box for the object’s geometry. Based on this it calculates the area of the largest side of the bounding box.

Area Bottom Net

The total area of all the downward-pointing surfaces of the object. The net area takes into account the openings.

Area Bottom Gross

The total area of all the downward-pointing surfaces of the object. The gross area does not take into account the openings.

Area Largest Net

The total area of the largest surfaces of the object. The net area takes into account the openings and the surfaces within the openings.

Note that sometimes a building element can be represented with multiple separate pieces of geometry. A good example of this is a strip wall. The Area Largest Gross and Net take into account all the surfaces in the same surface as the largest one. So in the case of a strip wall, all the surfaces on the largest side would be included in the result.

Area Largest Gross and Area Largest Net also takes into account the curved surfaces. So if you want to calculate an area of a curved wall, these are the quantities to use.

Area Largest Gross

The total area of the largest surfaces of the object. The gross area does not take into account the openings and the surfaces within the openings. 

Area Sides Net

The total area of all the side surfaces of the object excluding upward and downward pointing surfaces. The net area takes into account the openings.

Area Sides Gross

The total area of all the side surfaces of the object excluding upward and downward pointing surfaces. The gross area does not take into account the openings.

Cleaning up the overlapping surfaces

You can optionally clean up/subtract overlapping side areas from the result. Use the Clean Up Side Surfaces -option to do that. This could be used for example when calculating formwork for footings.

Area Top Net

The total area of all the upward-pointing surfaces of the object. The net area takes into account the openings.

Area Top Gross

The total area of all the upward-pointing surfaces of the object. The gross area does not take into account the openings. 

Area Total Net

The area of all the surfaces in the object’s geometry. The total net area takes into account the openings and surfaces within the openings.

The total net area is the area of all the surfaces of the object’s geometry you can see in 3D.

Area Total Gross

The area of all the surfaces in the object’s geometry. The total gross area does not taking into account the openings and surfaces within the openings.