Building Exterior Area Calculation

How to calculate building surface areas with Undet for SketchUp

To achieve successful results in renovation projects, you need to plan carefully and measure accurately. A key part of this planning process is to estimate the surface area of the building correctly. Whether you are updating a single room or transforming a whole building, knowing how to calculate surface areas efficiently is vital for estimating costs, acquiring materials, and managing the project. In this article, we will show you the most straightforward method and tools for computing building surface areas designed explicitly for renovation projects.


Point Cloud-based building modeling and surface calculation

3D laser scanners are essential for renovation projects, as they allow us to get a precise digital replica of the object we measure in Point Cloud format. However, to calculate areas, we need a 3D model, not a point cloud, so we must create a CAD model first. We have tested many CAD programs, but the simplest and quickest way to model and compute the areas of an existing object is to use #SketchUp and the #Undet Point Cloud plugin. So, let’s take a quick look at the recap of results which we can achieve.


Tagging building Elements for precise area calculations in SketchUp

Now, let’s take a few steps back and examine how we can calculate the areas we are interested in and how it all works. Please note that this article will not go into detail in creating a building model from 3D point clouds. If you are new to this topic, you can learn more from the tutorials and videos on the Undet YouTube channel.
So, we start from the fact that we already have a 3D model. In SketchUp, there is a TAG feature that allows us to label and colour different elements of a building model, such as walls, openings, reveals, sills, columns, etc. For each area we want to count, we will create a separate TAG and assign the faces of the 3D model to it.
By using tags and colours, we can easily identify the 3D model faces that correspond to each element and check if we have done everything right without leaving anything out or misclassifying anything.


Face area calculations: techniques and methods in SketchUp

After dividing the 3D model into separate TAGs, we can now measure the areas of different faces. We can use the SketchUp selection tools to pick any face and see its area in the entity info.
We can also choose multiple faces simultaneously to get their combined area. Or we can select a whole TAG, such as walls, and get the total area of that TAG. Remember that you can switch the TAGs on and off to concentrate on the area that matters to you.

The final step is to produce a report of the areas counted, which you can do using any text editor. Please note that you can attach a 3D model to the report to validate your calculations. This is very useful, especially if the customer will have any questions.

Table showing the surface areas of the 3D model

This is one of the ways to use point cloud data and SketchUp to calculate building surface areas. This method is simple and fast, providing accurate and detailed information. We hope you found this article helpful and informative. If you have any questions or comments, please feel free to contact us.

Software used in the video content:

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Undet works with SketchUp Pro (Windows only).