Key Concept:

Jorn Utzon’s design for the interior of the Sydney Opera House was developed through an iterative design process, where form was not penned, but discovered through acoustic and visual fitness. Here Utzon (in collaboration with Ove Arup and Partners) used software to calculate the reverberation time and geometric constructions of reflections within the constraints of a 2:3:5 (height: width: depth) ratio.

Utzon developed a calculated schema for his ceiling form to which he called “angles and radii”. This is a simple term for a complex system of 6 to 8ft section timber beams that span from the stage tower to the rear of the hall. Each beam is defined in space as each point of intersection on the radius is designated by a letter and number (i.e.: A1, B1...) Seen in the table below with then defines the X and Y axis. All Y co-ordinates are taken from the floor level of the stage, contributing to the rule-set of the whole space. On each rib, Utzon places multiple curves, defined by a subtractive cylindrical geometry in relation to the roof shells. Each surface has the same radii but is bisected at differing arcs.

Due to the nature of the site, Utzon had to squeeze more people into a constrained domain limiting the width of the hall and intern the viewing angles. As the ceiling system was defined by a point on the floor of the rear of the stage, the seating plan was defined by a radius extending out from the stage center point. This pushes out the side extremes of the plan without angling the seats towards an obstructed direction.

Selected Design element:

I have chosen to model Utzon’s proposed ceiling form for the opera hall starting at the top chord of the stage fanning out and terminating at the floor behind the rear most seats of the theatre. The beauty of the design will also be demonstrated as it is quite difficult to understand the nature of the structure not being a cylindrical regular section but a radial rib, and the reduction of a walling element that has been integrated into the roof structure. I will be investigating each rib section diagram and forming up each individually as how it was initially designed to be produced.

Concept integration into the design studio:

Understanding that Utzon’s approach to the formation for the ceiling form was not computationally derived, I do however feel that his approach to the schematic rigour of the control points and acoustic optimisation is a highly relevant approach to today’s computational design thinking. He deeply understood the fitness criteria and his method of approach to the iterative process of design as outlined in the letters between Utzon, and Arup. As a student with a background in computational design I have come to realise there is a distinction between the computer’s output and the architect’s idea. In our changing architectural enterprise we need to heavily cement the architect’s role as the schematic idealiser who is there to analyse and provide conceptual expertise armed with a computer to test and create what only the human mind can until now only attempt to resolve. Going forward I wish to use this as teaching exercise for myself to not let the computer create some form but for me as the designer to understand and curate the architecture so as to not end up with designs that are noted as “blobitecture” where form are created because they can, not because they should.

Geometric Description of the Shape:

Proposed Scale Material & Technique:

I propose to make a 1:100 scale of the ceiling structure, as at this scale I will be able to effectively steam bend the timber members without as much spring back as I would experience with a smaller scale. The model will be made out of timber that would be laser cut and bent.

Hours and Budget:

I have decided to introduce a less time intensive process for this model so I am able to balance hours with my other models. The time should take around 10 hours and I estimate it will cost $25 for the laser cutting session plus another $16 for the timber.