The back cover of the brochure for Lorenzo, shows this picture accompanied by a good discussion of Vitruvius and his principles.
Unfortunately no one signed the article. I would like to discuss the ideas, especially 'regulating lines', with the author, but I haven't yet found a way. So I am posting this here.
I don't think the star shows the regulating lines used to design the house. The star is not regular in shape. Shutters like the ones on the house in the photograph were not in use until about 20 years after the house was built, so those points are not important elements of the design. The pediment was also added later.
My sketch shows the basic elements of the original house: the shape of the facade, the pilasters which sit on brick pedestals that are part of the foundation, the arches which join the pilasters, the door with its sidelights and fan. The windows sit quietly between the columns.
Here are the regulating lines - superimposed in red - that I think were probably used to determine the proportion, rhythm, and details of the house. These lines were easily drawn with a compass ( or dividers), one of the tools we know house wrights owned in the early 1800's. The center block of the house is a square. The width of the wings on each side is determined by the diagonal of the square used as a radius. The three bays in the center box are also the same width as the wings, and are delineated by the pilasters. The importance of the pilasters is emphasized by the pedestals in the foundation wall, the arches which join them, and the placement of the posts topped by urns in the roof balustrade. Curves, circles, ellipses draw the eye: here to the 5 bays, the door.
The height of the entrance is determined by the center of the square. When the pediment was added, its height was determined by extending the arc of the diagonal. Its ellipse is the same curve as the fan light. Pretty simple: each piece is determined by the whole. The curves reinforce the concept.
I played with the arch over the windows. Hmmm. It was a structurally sound way to finish the brick pilasters and create a frieze. It emphasizes the bays and formal composition. But the curve? The photograph is too small to figure out where the radius of that arc originates.