Design, Education, Preliminary Design Stage Series

Episode 7: Bubble Diagrams and Functional Flowcharts

Bubble diagrams are freehand diagrams made during the preliminary design stage to help plan or zone spaces with similar functions. The bubble diagram is the first step made towards achieving a floor plan. The information from a bubble diagram helps plan out major functions in a building, spaces in the building, their relationships, and sometimes even circulation patterns.


A functional flowchart is also a freehand diagram which is drawn after the bubble diagram to generate main functions or spaces in the building, how they connect to each other and circulation routes in the building. This is like a rough sketch of a floor plan. A very common mistake made when dealing with functional flowcharts is that students usually generate the flowchart after they have completed the floor plan, while the flowchart is supposed to be done before the floor plan.

There are some similarities between a bubble diagram and a functional flowchart. A simple google image search on bubble diagrams, you would realize that the bubble diagrams and functional flowcharts are practically the same thing. However, architecture education sometimes differs from various parts of the world, therefore, we have bubble diagrams and functional flowcharts which are two different things. The ideal chain of generating a floor plan starts with a bubble diagram, then a functional flowchart, and finally a rough sketch of the floor plan.


How to do a Bubble Diagram

A bubble diagram is derived from the main zones/functions in a building. These zones/functions are obtained from case studies and literature review. Their positioning is however based on information from site analysis and site zoning. Fig. 1 shows an example of site for a residential design. In the first diagram, the site has been analyzed and discovered to have major sources of noise from the roads around the site. This resulted in the zoning of the site showing the proposed area for development in the second diagram. The third diagram shows how the bubble diagram has been developed within the proposed development area. The public zone and service zone is placed close to the most accessible part of the site, while the private zone is placed away from it. A buffer zone is also provided as a barrier from neighboring sites.

Fig. 1: How to derive a Bubble Diagram

The zones in the bubble diagram are derived through case studies and literature review. The main functions in a house include living areas, sleeping areas and supporting functions like cooking areas. These areas are grouped into public zones, private zones and services as shown below in fig 2.

Fig. 2: Spaces within Zones

How to do a Functional Flowchart

A functional flowchart comes after the bubble diagram. This represents how spaces are connected with one another. This usually gives an idea of how a floor plan would look like. In a residential design, the main spaces include the living room, dining room, kitchen, storage room, bedrooms and toilets. There might be other spaces like a foyer, laundry room, a study, etc. but it all depends on the nature of the design brief. Like a flowchart, these spaces are represented in a diagram with lines connecting them. The lines serve as circulation routes through the buildings.

Fig. 3: Bubble Diagram and Functional Flowchart

Zones and spaces in bubble diagrams and functional flow charts are peculiar to the nature of a project. It is important to be creative with your diagrams. Nice sketches or details can be added to help make the diagrams more appealing or explanatory. For example, in the design of a hospital, the bubble diagram was made to represent some sort of microorganism under a microscope (Fig. 4). In the design of a 5-star hotel, the functional flowchart was in 3D diagram showing how spaces interact on different levels (Fig. 5).

Fig. 4: Bubble Diagram for Hospital
Fig. 5: Functionality Sheet for 5-Star Hotel

The significance of bubble diagrams and functional flowchart cannot be over emphasized. It is important that they are done before any sketches of the floor plan are made. (NOTE: My designs were done before the establishing of Quif Studio. These current blog posts are written in line with research, my experience and through consultations. Any mistakes, omissions etc. that have been noticed in my designs, were made a few years ago. The sole purpose of sharing them is to give an idea of what each and every step should look like)

5 thoughts on “Episode 7: Bubble Diagrams and Functional Flowcharts”

  1. I’m a 200lvl Student Architect, I just started Design Studio and I have to say that your blog has helped me understand how to go about my studio projects
    Thank you very much, Godspeed.

    Liked by 1 person

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