The ideal light for green walls: ERCO guidance for healthier, more beautiful living walls

Oct 28 — 2025

The ideal light for green walls: ERCO guidance for healthier, more beautiful living walls

As green walls become signature features in offices, lobbies, retail, and hospitality, the right lighting is the difference between a lush, living surface and a flat backdrop. ERCO’s latest guidance distills how to design light that keeps plants healthy, highlights texture and depth, and elevates the experience of biophilic spaces.[1]

Planted walls, also called green walls, create a pleasant atmosphere and improve the indoor climate. Indoors, the factor of light plays a decisive role in ensuring that plants remain healthy and can thrive.

Why lighting matters for living walls

  • Plant vitality depends on sufficient, well-directed light over time. Balanced illumination supports photosynthesis, growth, and evenness across the full height and width of the wall.
  • Perception-oriented lighting adds depth and contrast so foliage reads as three-dimensional, not a flat plane. The result: a greener appearance, clearer textures, and a calmer atmosphere for occupants.
High-lumen output wallwashers impressively display the green wall in the foyer of the Bank of China in Sydney and ensure healthy plants.

6 planning essentials for green wall lighting

  1. Define target illuminance and uniformity
  • Set minimum maintained illuminance at the plant surface based on species and location. Aim for consistent vertical lighting so growth doesn’t patchwork over time.
  1. Choose precise distributions
  • Use wallwash or asymmetric optics for even vertical coverage. For articulated foliage or feature zones, combine narrow to wide flood beams to add accents without hot spots.
  1. Position luminaires for planar uniformity
  • As a rule of thumb in wallwashing, set the offset from wall to roughly one-third of wall height and keep luminaire spacing around 1.2–1.3x that offset. This helps achieve smooth vertical gradients from top to bottom.
  1. Balance spectrum and visual comfort
  • Use high-quality LED solutions with comfortable glare control and stable color over time. Where occupants spend long periods, maintain UGR-conscious layouts for wellbeing while meeting horticultural needs.
  1. Design for maintenance and longevity
  • Specify durable, serviceable luminaires with robust optics. Uniformity and output should be maintainable over the wall’s lifecycle, accommodating plant growth and seasonal change.
  1. Integrate controls intelligently
  • Dimming and scheduling keep plants on a consistent light regimen and save energy after-hours. Scene control supports day–evening ambience shifts while safeguarding plant requirements.
The arrangement of the luminaires and the distance to the wall also play an important role with the illumination of green walls. The ERCO whitepaper provides practical tips for the lighting design.

  • Uniform wallwashing for the primary vertical plane

Delivers consistent growth and a calm, continuous visual field. Start with dedicated wallwashers or projectors with wallwash lenses.

  • Accent layering for depth and hierarchy

Use spot or flood beams to articulate feature species, niches, or signage. Keep accent ratios moderate to avoid localized overexposure that can stress plants.

  • Indoor–outdoor continuity

For entries and atria that span inside to out, align distributions and color temperatures so the green wall reads as a single, coherent element across thresholds.


ERCO tools that make the difference

ERCO develops optics for exact vertical illumination, minimizing spill and maximizing effectiveness at the target surface. That precision improves plant health, visual comfort, and energy performance in tandem—key for sustainable interiors.


Bringing it to your project with William Artists

For over four decades, William Artists has delivered perception‑oriented lighting across cultural, commercial, and public spaces in Greater China. As ERCO’s regional partner, we help you:

  • Validate plant‑lighting criteria and calculate uniformity
  • Select optics and layouts for your wall dimensions
  • Integrate controls and commissioning for long‑term performance
  • Coordinate with façade, irrigation, and maintenance teams

Planning a green wall? Share your dimensions, photos, and plant palette—we’ll provide a tailored lighting concept and product shortlist.

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Illuminating the way to a greener future.