Architectural Bubble Diagram: what is it and why is it important?
The Architectural Bubble Diagram is a freeform drawing that supports the designer in spatial planning. Find out why it’s so important!
Whether you are a professional with decades of experience, or you are just starting your career as an architect, engineer or professional interior design software, you may have noticed that the space planning phase plays a crucial role in the design process of a building, whether residential, or intended for other activities.
During this phase, designers perform an in-depth analysis of the users’ requirements and define the functional-spatial characteristics that the various environments must meet in terms of size, location, accessibility, reciprocal connections, and so on.
To ensure a correct and efficient spatial planning, it’s always useful to show this information in graphical form within a diagram called the Architectural Bubble Diagram. Let’s find out more about this system!
What is an Architectural Bubble Diagram?
The Architectural Bubble Diagram is a freeform schematic drawing used by designers to support space planning and organization during the preliminary design phase.
In the bubble diagram, spaces that make up the building (or the single accommodation) are represented by a series of circular (or oval) shapes of different colors and sizes, each of which has the objective of specifying function, characteristics and degree of importance of each space compared to others.
In addition to classifying the functional areas of the building, the Architectural Bubble Diagram describes the types of relationships between spaces, using different types of arrows and lines that link up the bubbles” (for example, the designer can use continuous or dashed lines to identify stronger or weaker links between two spaces).

Example of an Architectural Bubble Diagram
Architectural Bubble Diagram: So why is it so important?
Bubble diagrams are essential because they represent the first step towards the realization of a building plan and represent the basis of the subsequent phases of the design process.
The main scope of using Architectural Bubble Diagrams is to represent the organization and interaction of spaces within a building. These diagrams are used mainly in the design of functional aspects, while they tend to be less efficient when dealing with aesthetic design aspects.
The information that bubble diagrams are able to show essentially refer to:
- function and layout of spaces;
- the relationships that exist between these spaces;
- circulation patterns and models.
You may be wondering, why should I develop a preliminary Architectural Bubble Diagram, instead of simply drawing up my own building plan?
Well, there’s quite a simple answer to that question: creating a bubble diagram helps you to put your creative ideas on paper, without worrying about what the final aspect of your project might turn out to be.
In the initial design phase, designers are not particularly interested in the exact dimensions of spaces, but define shapes and proportions of rooms thinking of the building as a whole.
The bubble diagram allows you to quickly experiment with different spatial distributions, which can then be reviewed and refined, and analyze and verify each element of the project in a simple and immediate way, in order to find the optimal solution.
How to draw an Architectural Bubble Diagram
Generally, the definition of an Architectural Bubble Diagram starts from a spatial planning phase, which relies mainly on gathering customer feedback in order to outline the building’s requirements.
During this first phase, a “program” with a list of details is prepared and in which the required individual building spaces are described with their main function, activities that will take place inside and the overall dimensions. The bubble diagram helps designers to graphically illustrate the program ensuring more efficient space planning and organization.
So, let’s see which steps you’ll need to follow if you want to try your hand at creating your own Architectural Bubble Diagram!
- Build a list of all the activities that will be carried out in the planned building identifying all the necessary spaces;
- For each of these spaces, specify a probable size (small, medium or large space);
- Evaluate possible interactions between spaces and identify their position;
- Analyse the requirements that spaces must meet in terms of lighting, acoustic insulation, indoor air quality, etc. (for example, environments requiring direct lighting and ventilation must be positioned at the edge of the diagram and never at the centre);
- Start drawing the bubble corresponding to the main space of your project, making sure that all sizes reflect the proportions of the considered environment;
- Continue to add the bubbles corresponding to the remaining spaces, drawing them with the correct dimensions (small, medium, large, etc.) and in the right position, also considering interactions with other surrounding spaces;
- Complete the diagram with lines and arrows indicating accesses and circulation paths, also highlighting relationships between the different functional areas.
Once you have built your bubble diagram, and identified the optimal layout for your building, you can develop the following design steps with more confidence and with a clearer idea of the planning requirements.
In particular, if your project involves BIM workflows, you can rely on professional professional interior design software, which in a single integrated solution helps you design interiors from CAD drawings or BIM models, obtain 2D plan views, 3D views and produce photorealistic renderings with great simplicity and power.