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Green Architecture: A Return to Nature's Principles

By Eric Stengel

In the living world of nature, there is a common thread that binds all things together: from seed pods to the spiral pattern of a sunflower's bloom, to insects, reptiles, butterflies, trees and to all the bones in an animal and to our own bodies. This thread is what allows nature's progression from the "one to the many" and is what Plato called "nature's greatest secret": phi.

Phi is a never ending and never repeating number: 1.618….It is a geometric mean, a proportion derived from a static geometry – the 1:1 square. For the ancients, this ratio was a sacred truth found empirically in all things in heaven and on earth. They fully believed it was a gift put on earth by the gods for man to find and use as a means to pay homage to the heavens. Its use was a literal portal to directly to the "soul of the universe."

The first evidence of the use of phi in architecture can be traced back 4,000 years to Egyptian architecture. Fast forward to Western legend, which says that Pythagoras (570-ca. 495 B.C.E.) was the first to have discovered the existence of phi though it wasn't formally identified until Euclid (325-264 B.C.E.). The phenomenon had many names until the first treatise on the subject – Divina Proportione by Luca Pacioli (1445-1517 AD) gave it its current and most commonly referred to name. In the Proto-Renaissance through the Renaissance, the church required that the phi ratio be used in all ecclesiastical architecture, much as in the past for temple architecture. The Pope called it "the golden rectangle" and "the divine proportion."

Understanding phi provides a gateway to the geometries of nature and the ephemeral thing we call beauty. When one makes things using phi, one gives form to the geometries of nature that also mimics its progression of scale. These things put man in harmony with the natural world and in doing so, these things, or objects, resonate with us. Phi is the fundamental thread connecting parts to a whole.

Harmony generally means a resonance between different things. In music, as in nature, there are several fundamental and recurring proportions that nature uses to go from the "one" to the "many" – unison (1:1), octave (2:1) and diapente (3:2). Unison is a single sound, like a plucked string. An octave is a sound played in intervals of eight. Diapente, or "through five," is called a fifth. The diapente ratio of 3:2 is the musical reconciliation of the phi dilemma of cumulative irrational numbers.

Scientific observations of nature's creations continue today to reveal the complex harmonic relationship of parts to a whole. For example, a scientist studying the propagation of mosquitoes looked at the sounds male and females make during courtship, in particular the sound of their beating wings. He measured the male beating wing sound to be a 600 hertz cycle, or approximately the musical note D5. The female wing beat at approximately a 400 hertz cycle, or approximately the musical note G4. When the two came near each other, both adjusted the pitch of their wing beats slightly to make a harmonic resonance. This adjustment did two phenomenal things. First, the two notes made a harmonic overtone; second, the pitch was what modern musicians call a "perfect fifth," meaning one note is seven semitones above or below the other. The note D is a perfect fifth interval above/below G. That's a ratio of approximately 3:2, or essentially phi. That is nature's greatest secret in a practical demonstration – making many from the one with harmony.

As in music, architecture, across all cultures, times and places, embraces these proportions, interpreted and developed through the centuries of a complex and rich language. This is the foundation of the Classical language of architecture. Its evolution as a language pays homage to nature by sequencing what we make with nature to produce a resonance. Think of the time you have been in a place and thought, this space feels right, it's comfortable.

Authentic green architecture, I propose, follows antiquity's principles of harmony and conservation. Phi proportions found in nature are the starting point for this mission, as evidenced throughout history. My Phi Guest Cottage is an example of harmony and adaptive reuse in the true spirit of Classical architecture. In fact, most materials used in this cottage were collected and saved during the last 200+ years here in Tennessee. Materials include 150-year-old hand-painted wainscoting, 100+ year-old reclaimed poplar floors and 100+ year-old barn timbers and re-milled, reclaimed old-growth lumber. The new components are also inherently green due to the low carbon emissions in production, as well as future upkeep. There are overhangs to protect vertical surfaces from the elements; low window/wall ratios on correct exposures to maintain a comfortable climate; and many natural, inert materials. All of these things combine to create a dwelling with a very low carbon footprint before, during and after its life – not just for the time of its intended use. This is how the ancients built, and many of their buildings survive today, after thousands of years. Think of the 1,880-year-old Pantheon – it has only five cracks in its lime-based concrete dome.

My green house embraces Classical ideals in a simple vernacular structure, utilizing harmonic proportions; strong, heavy, natural and inert materials that require little processing; the reuse of materials; low window to wall ratios; and passive solar performance through thermal mass and orientation to the sun.

If we continue with what is now a scorched earth policy of consumption, we cannot sustain nature's limited resources. The writing was on the wall in the 1880s, 1960s and 1970s and now again in the 21st century.  


Eric Stengel is the principal of Eric Stengel Architecture, LLC, in his native Nashville, TN. Founded in 1991, the firm specializes in the Classical language of architecture.

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