July 18th, 2012

Mimic a Master Builder: A Tribute to Felix Candela

Felix Candela (Madrid, Spain, 1910 – Durham, NC, US, 1997) was an architect with a very busy, productive, creative, and interesting life. In Architecture, he is known as a master builder of thin shell structures.

This article provides a method to use Autodesk® Revit® to model, and control by parameters, the basic version of nine types of forms that Felix Candela used, with several variations, during his career.

For each of these nine forms, this article contains a scheme, an image of the model, and a photo of one of the projects in which Felix Candela used that type of form.

To understand the schemes, please refer to the following legend of symbols.

The workflow

Do you want to make one of these forms? Here’s the workflow.

Start a new Revit family with the generic model adaptive template.
Create reference planes in plan view.
Create dimensions and parameters to control the reference planes.
From a front view, create one or two reference planes to control the height, as needed.
Name the reference plane(s).
From the plan view, create Reference Lines, as indicated with the green lines of the scheme.
From the plan view, create reference Splines, as indicated with the red lines in the scheme.
From a 3D view, select the points indicated in red in the scheme, and from the options bar, change the host to each point to the corresponding named reference plane.
Select sets of Reference Lines and/or Reference Splines, and then Create Form. Repeat as necessary.
It is not necessary to divide surfaces. The division is shown in these images for illustration purposes only.
Load into project.
Create a concrete wall type, very thin. (Candela used 1-1/2” in some projects, and 4” in the Bacardi Rum Factory).
From Massing and Site, use Wall by face, and select the surfaces of the form.

1. Conoid

This form consists of three horizontal edges and one arc.

2. Straight hypar

This form is a hyperbolic paraboloid, generated by straight lines. The short name for hyperbolic paraboloid is hypar. A hypar is a ruled surface in two directions: arches in one direction, and inverted arches (or cables) in the other direction. Most of Felix Candela’s forms are variations of the hypar, either generated by straight lines or curves, and with straight or curved edges.

3. Group of straight hypars

This form is the result of grouping several panels of form # 1, the basic straight hypar. The four corners remain at the reference level, while the mid points of each edge are elevated to another plane. In Revit, each panel needs to be converted into a surface; each reference line at the center is used twice, to generate the surface of two adjacent panels.

4. Umbrella of four panels with one central support

This form was used by Felix Candela in many of his projects to cover large areas such as warehouses, factories, malls, and farmers’ markets. In Revit, each panel needs to be converted into a surface; each reference line at the center is used twice to generate the surface of two adjacent panels.

5. Curved hypar, saddle

Three arcs define this form. The lower elevation of the middle arc converts this shape into a hypar. Several variations are possible, if the nine defining points are moved in plan or elevation, after this basic shape has been obtained.

6. Dome with square plan, with an arc on each side

Three arcs define this form. The central arc defines the top. This form has been used to cover large areas, such as sports arenas.

7. Two curved hypars, intersected

This form is the result of intersecting two saddles, like the one shown in form # 5. The central point goes to the lower reference plane. The four corners define the supports.

8. Three curved hypars, intersected

This graceful form is the result of intersecting three curved hypars. The central point goes to the lower reference plane. There are only three points of contact with the ground.