Comfort as a guiding principle

LIGHTING MASTER PLAN

Visual comfort as a guiding principle – light quality over quantity

For decades, public lighting was primarily defined by its brightness. Good lighting was considered to be as bright, uniform, and widespread as possible – assessed based on measurable values such as illuminance or uniformity, not on visual quality. This way of thinking is deeply embedded in technical regulations, political decision-making processes, and the understanding of safety in many cities – and is long overdue for an update.

For an overview, the lighting master plan
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In practice, this logic frequently led to over-dimensioning. Out of uncertainty and the concern of providing „too little light“, lighting levels were increased without considering their effect in the space in a differentiated manner. The Ingolstadt light master plan consciously questions this paradigm – not for the sake of design, but based on physiological, perceptual psychological, and urban spatial findings.

The focus is on visual comfort: the quality of vision in nocturnal space.

1. Why „more light“ doesn't mean better vision

The human eye is not a passive sensor, but a highly adaptive system. It continuously adjusts to the average luminance level of its surroundings. Therefore, what is crucial for good vision is not the absolute amount of light, but the interplay of luminances, contrasts and glare across the entire field of vision.

Excessive or poorly controlled lighting can significantly disrupt this process:

  • High luminance levels force the eye to adapt to an increased brightness level.
  • Darker areas become less perceptible as a result.
  • Blendquellen erzeugen Streulicht auf der Netzhaut und reduzieren das Kontrastsehen.

The result is paradoxical: despite more light being available, visual performance deteriorates. Orientation becomes more difficult, reaction times lengthen, and uncertainty arises not despite, but because of unsuitable lighting.

Light behaves similarly to acoustics in many ways here: in a train station hall with poor acoustic conditions, announcements become less understandable even as the volume increases. The more complex and loud the acoustic environment becomes, the more difficult orientation and concentration become. Overloaded lighting has a similar effect: the brighter, more heterogeneous, and more restless the luminance levels in the environment, the lower the visual quality.

The lighting master plan addresses exactly this and shifts the focus from the quantity of light to the effect of light.

2. Seating comfort as an integrative quality criterion

Visual comfort describes the interplay of several factors that together determine the visual quality of a room. It is not a single measurable value, but an integrative quality criterion.
This encompasses visual comfort, which not only refers to physiological visual performance but also spatial perception, security of orientation, and subjective readability.

The key influencing factors are:

  • balanced luminance ratios across the entire field of view,
  • low glare from direct and indirect light sources,
  • targeted light guidance to direct attention,
    the legibility of the space through appropriate use of light: vertical surfaces, room edges, rhythm, zoning, and conscious contrast.

High visual comfort allows lower illuminance levels to be used without compromising safety or orientation. It therefore forms the basis for energy-efficient lighting solutions that are also of high quality.

3. Uniformity Reimagined – Readability Instead of Homogeneity

Traditionally, uniformity was often understood as the most homogeneous illumination possible. In the Lighting Master Plan, this concept is interpreted in a more differentiated way.
Not every surface needs to be equally bright.

Crucially, spaces must remain readable:

  • Dimensions must be recognisable.
  • Room edges and transitions should remain visually discernible.
  • Different areas of use may differ without creating visual breaks.
  • Rhythm and zoning support the perception of spatial depth and structure.

Excessive homogeneity can make spaces appear flat, contourless, and disorienting. Visual comfort is rather created by balanced contrasts and a clear hierarchy of light distribution.

4. Glare as a central quality risk

Glare is one of the most common and yet underestimated sources of disruption in public spaces. It is not caused by bright lights alone, but primarily by unfavourable positioning, high luminance levels, and insufficient shielding.

The lighting master plan does not treat glare as a marginal issue, but as a central quality criterion. Both physiological and psychological effects are taken into account:

  • Physiological glare impairs vision immediately.
  • Psychological blinding creates irritation, uncertainty, and unease.

Glare is particularly critical in darker environments, at transitions, or in mixed-use areas. Here, visual strain increases significantly when individual light sources dominate. Consistent glare limitation not only improves safety but also the acceptance of lighting in urban spaces.

5. Thermal comfort as a prerequisite for safety and quality of stay

Safety in public spaces is not created by maximum brightness, but by clarity, orientation and visual calm. Visual comfort is therefore a central prerequisite for objective and subjective safety.

Rooms with good visual comfort:

  • are used more often and avoided less,
  • seem manageable and controllable,
  • fördern soziale Präsenz und informelle Kontrolle.

The lighting masterplan therefore consistently links visual comfort with questions of space quality and social use. Squares, paths and transitions are not just illuminated, but visually structured.

6. Consequences for planning and operation

Orientation towards visual comfort has direct implications for planning, implementation, and operation:

  • Illuminance levels are chosen contextually, not maximised across the board.
  • Light guidance and shielding take precedence over additional light output.
  • Operating profiles such as dimming and time control enhance light quality through situation-specific adjustments.

This makes visual comfort a permanent design principle – not a one-off aesthetic decision.

Lighting quality as a strategic lever

By placing visual comfort at its core, the Lighting Masterplan fundamentally shifts the discussion around lighting. Light is no longer treated as a purely technical supply issue, but as a quality-determining factor of urban space. Light quality replaces light quantity as the benchmark – thereby creating the basis for a sustainable, legible, and identity-creating nightscape.
DAY&LIGHT Maxplatz ChristophMittermueller
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