Lighting in Architecture: Enlightened Thoughts

What makes lighting more than just a utility? In this engaging and often humorous session at Mercer Zimmerman’s Light+ event in Des Moines, John Rucker explored how light shapes emotion, perception, and spatial experience—from Renaissance paintings to modern office design. With insights drawn from art history, technical evolution, and personal anecdotes, John challenged attendees to think of lighting as a storytelling tool. We caught up with him after the session to unpack the big ideas.

You say lighting is more than visibility—it’s presence. What do you mean by that?

Light defines space, but it’s the absence of light—shadow—that gives it depth. Without contrast, everything flattens out. In art, chiaroscuro brought realism to painting. In architecture, shadows help us perceive shape and emotion. Light isn’t just functional—it’s expressive. It tells us where to look, how to feel, and what matters.

What’s changed in lighting technology, and what still matters most?

LEDs changed the game. We’ve moved from strapping incandescent bulbs to wood panels to sculpting light with precision. Today, it’s not just about efficiency; it’s about control. Direction, diffusion, integration. Daylight remains the gold standard, and how we guide it through architecture makes all the difference. Even the same room can feel entirely different depending on whether you light the horizontal or vertical planes.

You shared a story about your wedding venue—how did lighting transform that space?

The venue had beautiful windows, but at night they turned into black panes, making the space feel closed off. I asked if I could bring in a lighting designer to add temporary landscape lighting. Once the oak trees outside were lit, the windows—and the room—came alive. It felt bigger, warmer, and more connected. The venue coordinator even asked for the designer’s contact—it completely changed the vibe.

How do color and material choices shape the experience of light?

Color temperature is huge. Warm tones feel cozy and inviting—think candlelight. Cooler tones support focus and productivity. We’re seeing more hospitality-inspired lighting in workspaces and healthcare. Materials matter too. White tile reflects light and brightens a space; dark finishes absorb it and create intimacy. Even identical fixtures can behave differently depending on finish—some blend in, others stand out

What’s the latest in measuring light quality—and why does it matter?

CRI was the old standard, but TM-30 is the future. It evaluates fidelity across 99 colors, not just 15. That means better accuracy in how we see reds, blues, and skin tones. For example, early LEDs struggled with red—in the case of produce, it could make delicious, deep red strawberries look dull. Now we can tune lighting to enhance or mute specific colors, which is critical in retail, healthcare, and art. Quality lighting ensures what you see is what you get

What’s your advice for designers who want to do more with light?

Be intentional. Lighting should support the story you’re telling. Use contrast to guide attention. Layer light to create mood. Integrate fixtures thoughtfully—some should disappear, others should shine. Whether it’s a gallery, a grocery store, or a sacred space, lighting shapes what people notice, how they feel, and what they remember.

The first photo focuses on the floor, while the second photo illuminates the walls, creating two distinct environments in the same space.