Early Shading Diagrams

One of the basic conclusions of The Solar House is that a few architects in the 1930s sought and achieved a new scientific understanding of passive solar heating and then shared this knowledge with wider audiences. Architects did not have easy access to information about solar geometry before the 1930s, but this became fundamental as they desired more glass and wanted to design proper overhangs or other shading devices to avoid overheating. With knowledge of solar angles, the shading diagram became a new element in the modern architect’s graphic and analytical toolbox.

Who made the first shading diagram? Previously here on the blog I’ve said: “[Fred] Keck probably made the first 2D shading diagram just before Le Corbusier, in 1936 or 37” (link) and: “We may never know definitively who drew the first 2D shading diagram, but clearly the convention came of age in 1937-38.” (link)

Here’s a “new” contender for the earliest shading diagram, from Architectural Record in March 1935. Of course it’s not “new” at all but I seem to have missed it until now and I’ve never seen it mentioned anywhere else. This is part of a larger article and neither an author or illustrator is credited. But I can say with some certainty this must have been created by Henry Wright, the elder, a housing planner who contributed to Architectural Record in this period and studied solar geometry.* Obviously, this is a generic illustration, because the location isn’t specified and the angles will vary by location—hopefully the readers understood this.

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And to reiterate, some earlier sun diagrams, such as the famous 1930 drawing by Walter Gropius (below), were not related to solar heating/overheating. As I wrote in the book: “[it] showed how housing blocks should be spaced to avoid self-shading using a low winter sun angle. This diagram is sometimes misrepresented as an early demonstration of passive solar heating, but the goal was to provide illumination and therapeutic sunlight, not to save energy.” In fact, these blocks faced east-west, as discussed here.

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*Henry Wright later wrote “Site Planning and Sunlight,” American Architect and Architecture (August 1938), where an early heliodon was shown. His son, Henry N. Wright, also created important resources for solar architects for Architectural Forum in the late 1930s, as discussed in the book and seen here. In The Solar House I also discuss Henry N. Wright’s contribution to the scientific understanding of thermal mass in the 1940s.