Architecture Beyond the Human Eye

Ibrahim Fawakherji — ArchUp

architecture and animal vision

After the response to the Cat's Eyes piece, a question arrived that I had not seriously considered in twenty years of practice.

We spend our professional lives designing for human perception. The user, the visitor, the pedestrian, the client standing in front of the building for the first time. We calibrate proportion, material, light, and color against a single reference point: what the human eye receives and what the human nervous system does with it.

But the building does not exist only for humans.

Every structure we raise immediately becomes part of an environment shared with other species, each of which processes the same physical object through a completely different perceptual system. The cat sitting on the wall sees something. The dog passing on the street sees something. The bird banking over the roofline sees something else entirely. The snake warming itself against the south-facing stone sees something that has no color in it at all.

None of them are seeing what we see.

Which raises a question that architecture has almost never asked: what are they seeing, and does it matter to how we design?

The Visual Biology: What Each Species Actually Receives

Dogs possess two types of cone cells in their retinas, compared to three in humans. This means they cannot distinguish red from green. Their color world is a range of yellows, blues, and grays. What they sacrifice in color discrimination they gain in motion sensitivity and low-light performance. For a dog moving through a contemporary streetscape, the expensive material palette of a facade is largely irrelevant. What registers is movement: the reflection shifting in a glass panel, the shadow crossing a threshold, the thermal shimmer above a dark paved surface.

This comparative graphic illustrates the stark difference between human and canine perception of the built environment, highlighting how dichromatic vision alters the experience of architectural spaces.

Cats have a similar color limitation, perceiving the world in muted blues and grays with very little red or green saturation. But their rod cell density is exceptional. In low light conditions where human vision fails, the cat navigates with precision. The architectural implication is that the night environment of a building, which designers typically address only in terms of artificial lighting and security, is a complete and richly detailed perceptual landscape for feline inhabitants. What reads as an empty plaza after dark is, for the cat, a fully legible terrain.

This visual comparison graphic contrasts a brightly lit daytime human view of an urban building courtyard with a simulated feline perspective, illustrating a dramatic shift to monochromatic, low-light perception.

Birds operate at a different level of perceptual complexity. While humans possess three cone cell types sensitive to red, green, and blue, many bird species possess four, adding a fourth receptor sensitive to ultraviolet light. This is not a minor enhancement. It means birds see patterns, markings, and surface variations that are entirely invisible to human eyes. A glass facade that appears uniformly transparent to an architect standing at street level may, from a bird's approach angle, carry UV reflections that read as open sky, which is precisely why bird-glass collisions occur at the scale they do globally. Estimates suggest between 100 million and 1 billion birds die annually from glass collisions in North America alone. The problem is not that the birds are confused. It is that we designed the glass exclusively for human perception.

This conceptual graphic visualizes the urban environment through avian eyes, demonstrating how the ability to perceive ultraviolet light radically alters the appearance of buildings, glass, and natural elements.

Snakes of certain species, including pit vipers and pythons, possess infrared sensing organs located in pit organs on their faces. These detect thermal radiation in the range of 5 to 30 micrometers, effectively producing a heat map of the environment independent of visible light. A building viewed through this system has no color and no surface texture in the conventional sense. It is a thermal landscape: the south-facing masonry wall that has absorbed six hours of sun, the metal door frame that conducts and radiates, the glass that transmits and the concrete that holds. The architectural geometry remains, but it is expressed entirely in thermal mass and thermal conductivity rather than in form or material finish.

Bees see a spectrum shifted toward shorter wavelengths. They perceive ultraviolet clearly, along with blue and green, but are blind to red. More importantly, their temporal resolution is approximately five times faster than human vision, meaning they process visual information at a rate that would appear as a slow-motion film from their perspective. The UV patterns on flowers that guide bees to nectar, invisible to humans without special photography, are their primary navigational information. A garden designed entirely by human aesthetic standards may be visually confusing or uninformative to the bees it depends on for pollination.

Deep-water fish experience a progressive loss of color as depth increases. Red wavelengths are absorbed within the first ten meters of water. Orange and yellow follow. At significant depths, only blue remains. A fish living at depth inhabits a monochromatic world not by neural limitation but by physics: the color information simply does not reach them. The architectural implication, for any aquatic environment or submerged structure, is that color selection below certain depths has no biological audience.

Discussing fish might seem unrelated to architecture, but it's actually present in hundreds of projects featuring enormous aquariums, whether in hotels, restaurants, shopping malls, museums, or public aquariums. We design these aquariums to be visually stunning, but the creatures living inside see a completely different world. Many fish have varying vision depending on their species, water depth, and lighting quality, and some even lose the ability to distinguish certain colors as the depth increases. This means that the choice of background colors, lighting intensity, glass reflections, and even hiding places within the aquarium affect not only the visitor's experience but also the fish's comfort. Here, the design transforms from mere aquatic decoration into a living environment that must consider how the fish perceive their world, not how we want it to be.

What This Means for Practice

The conventional architectural brief considers human occupants as its sole perceptual reference. This is understandable, since buildings are commissioned by humans and used by humans. But three developments are making the broader perceptual question increasingly relevant to professional practice.

Bird-safe design has moved from an environmental footnote to a building code requirement in several jurisdictions. New York City's Bird-Friendly Building Design law, enacted in 2019 and updated in 2021, requires that new construction and major renovations use materials and patterns that reduce bird collision risk on the lower portions of buildings and any high-risk features such as balcony glass and sky bridges. The technical solution involves applying patterns at specified densities to glazing, using fritted glass, or selecting materials with lower UV reflectivity. These decisions, which are invisible to human occupants in most conditions, exist specifically to address the perceptual gap between human and avian vision.

Urban biodiversity frameworks are now included in sustainability certification systems including BREEAM and, increasingly, in municipal planning requirements in European cities. These frameworks ask designers to consider habitat continuity, light pollution effects on nocturnal species, and surface material choices that support or exclude pollinator access. The consideration is no longer optional in jurisdictions that have adopted biodiversity net gain requirements.

This comprehensive comparative infographic illustrates the dramatic differences in how humans, dogs, birds, and thermal sensors perceive the exact same architectural environment.

AI simulation tools have made it technically feasible, for the first time, to visualize a building design through approximate simulations of non-human perceptual systems. Software can apply dichromatic filters that approximate dog or cat color vision, shift image spectra to simulate UV sensitivity, or convert visible light images to thermal map representations. These tools are not perfectly accurate models of animal neurology, but they provide designers with a useful departure from the assumption that their own visual experience of the design is the only relevant one.

A practical workflow application: before finalizing a glazing specification on a facade with significant bird flight paths nearby, running the proposed design through a UV simulation can identify surfaces that are likely to read as transparent sky from an avian approach angle. Adjusting frit density or pattern based on that simulation adds no cost to the design decision but potentially eliminates a significant ecological liability.

The Design Question This Opens

For most of architectural history, the human eye was the only measurement tool that mattered. The building was experienced by humans, evaluated by humans, and photographed for humans. The perceptual systems of other species were not part of the design calculus.

This assumption is becoming harder to sustain.

The city is not a human-only environment. It is shared with a large number of species that did not choose to inhabit it but have adapted to do so, and whose presence in the urban environment provides services, from pollination to pest management to the psychological benefit that human inhabitants derive from biodiversity, that the built environment depends on whether or not it acknowledges them.

The specific question for architecture is not whether to prioritize animal welfare over human use. It is whether the design process can expand its perceptual frame of reference to include, at minimum, the most common and most consequential non-human interactions with the built environment.

A facade that kills birds through perceptual deception is not a well-designed facade, regardless of how it reads in the project photographs.

A garden that excludes pollinators through its plant and material selection will not function as intended, regardless of how it reads in the landscape plan.

A lighting scheme that disrupts nocturnal species across an urban block is imposing a cost on the broader ecological system that does not appear in the project budget.

These are not sentimental observations. They are design performance criteria that are beginning to be recognized as such in the more advanced sustainability frameworks, and that will become standard considerations as urban biodiversity requirements expand across more jurisdictions.

The buildings we raise outlast the design process by decades. During that time, they exist within a perceptual field that extends far beyond the human eye. Every surface, every material, every light source, every thermal mass is producing information that other species are reading and responding to, whether or not we intended to send it.

We have been designing buildings for one type of eye for the entirety of the profession's history.

We are only beginning to understand what the other eyes are seeing.

✦ ArchUp Editorial Insight

The hundred million to one billion birds that die annually from glass collisions in North America alone are not the victims of a design oversight — they are the measurable cost of a procurement framework that has never required designers to account for any perceptual system other than the one held by the client signing the approval. Bird-safe glazing specifications, UV-sensitive fritting patterns, and thermal mass modeling for non-human inhabitants are technically available and in several jurisdictions now legally mandated, yet their adoption remains exceptional rather than standard, which reveals that the constraint was never technological but contractual: the brief does not ask for it, the liability framework does not penalize its absence, and the photography through which architectural value is communicated cannot capture what it prevents. The article's deepest structural contribution is not its perceptual biology — which is accurate — but its implicit argument that the human eye has functioned not merely as the primary reference point for design but as an exclusionary governance mechanism, determining which consequences of a building's existence are legible as design performance and which are externalized as ecological noise, a condition directly continuous with what The Economics of Indoor Air Quality identified in the CAPEX-OPEX gap: the party whose biology absorbs the building's failure — whether tenant lung or migratory bird — is structurally absent from the procurement conversation that determines whether the failure occurs.

https://archup.net/brain-rot-in-the-rabbit-hole/
https://archup.net/a-place-of-worship-a-school-or-a-hospital/
https://archup.net/cat-eye/