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When light offers a warm welcome. Attractively designing foyers with qualitative lighting design.

When light offers a warm welcome. Attractively designing foyers with qualitative lighting design.

The foyers of companies, educational facilities and cultural establishments serve as visiting cards. They communicate a first impression of an organisation or company and can arouse curiosity to find out more. To achieve orientation and create an appropriate atmosphere in an organisation are some of the strengths of lighting design aiming for quality. We demonstrate how visitors can be made welcome with light, from the concept stage to a planning example.

Often designed as a generously dimensioned, high entrance space, foyers serve representative purposes and at the same time function as reception and maintenance areas as well as providing access to other areas of the building. As the transition between outside and inside as well as between the public and private space, differing spatial scales come together. As a consequence, supporting orientation with light within these various functions and areas gains high relevance. However, light can offer much more than just identification and orientation. The emotional side of light, used for example as a discreet or more vivacious impact in the space, can ideally be used to achieve an attractive sense of welcome. Furthermore, the lighting of a foyer can also provide a valuable contribution to making the identity of a company visually perceptible. The design flexibility of light with regard to the self-presentation of a company-, educational- or cultural brand, ranges from an unobtrusive and sober ambience to dramatic displays.

Thinking in quality of light instead of lux values

Technically well-informed designers start a quantitative lighting design for foyers by using the appropriate standards. Designers need to be guided by key figures for illuminance, uniformity and glare evaluation but should also be careful not to ignore the qualitative elements. Because numerical values for safety, orientation and work tasks were decisive during development of these standards, design aspects were hardly integrated. As a consequence, project managers often focus precisely on considering limit values in the design process even though they lack experience as to whether slight deviations might already cause significant difficulties. Qualitative lighting design on the other hand focuses more holistically on perception, taking into account requirements concerning visual tasks as well as psychological needs when aiming for higher levels of well-being.

A change in perspective: ambient luminescence, focal glow and play of brilliants

Richard Kelly (1910-1977) is seen as the pioneer for perception-orientated lighting design. He substituted the question of light quantity by the three categories of "ambient luminescence", "focal glow” and "play of brilliants". Ambient luminescence comprises simple general lighting. This method of lighting, achievable with downlights or uniform wallwashing, provides orientation and gives a feeling of safety. This is important in foyers where a sense of safety should be communicated to visitors within this initially unfamiliar terrain. Focal glow is concerned with accented light that highlights objects, surfaces and spatial zones and also creates hierarchies in perception. It is also a central means of guiding the attention of observers when displaying pictures and sculptures. This plays an essential role in reception areas because individual sections can be emphasised in large spaces, for example reception desks, stairways, other circulation areas and prestigious artworks. Play of brilliants is decorative light: either light for admiring or an aesthetic end in itself: this includes light effects with coloured light as well as decorative luminaires and installations of light art that create a sense of excitement in foyers. Lighting concepts are deemed successful if all three components – general lighting, directed and decorative light – are combined in suitable proportions.

Kelly's categories are also ideal for clearly explaining the complexity of a lighting solution to constructors and for drawing up concepts for foyers. Lighting designers can of course also dispense with categories if they wish to create a special light effect, for example the avoidance of general lighting when creating especially dramatic presentations with accent light. Kelly developed a masterpiece in qualitative lighting design for the prestigious foyer of the Seagram Building in New York, designed by the architects Mies van der Rohe and Philip Johnson and completed in 1958. The grazing light on the cubes for the elevators not only provides orientation but also communicates a high-quality impression when entering the building thanks to a finely nuanced play of light and shadow on the travertine walls. For passers-by on the plaza outside, the vertical illuminance creates a bright and transparent spatial impression of the fenestrated foyer. The brightly flooded ground floor also gives the skyscraper a pleasantly lightweight appearance. Downlights installed along the façade create the impression of a carpet of light between the interior and exterior and also emphasise the prestigious welcome. The principles of vertical illuminance and light carpets have lost none of their relevance in the present day and age because they reference general psychological needs with regard to perception.

Supporting orientation with light

William Lam (1924-2012), one of the pioneers of perception-orientated lighting design, specifies the need for orientation as the most important fundamental requirement of psychological perception for rooms. This initially includes spatial orientation and the recognition of routes and targets. With foyers this applies to the reception, entrances to the rooms and waiting area. The relevance of the zones can be hierarchically structured using differing illuminance levels to support the inherent readability of the surroundings. An illuminance contrast of 1:2 is hardly suitable because the eye is hardly able to perceive this. As a consequence a contrast of at least 1:5 is recommended in relation to the surroundings. In large rooms, graduated depths also help to differentiate the foreground from the background. Greater brightness on the rear wall in relation to the entrance helps to direct attention towards the rear area of the foyer. Differentiating between the public reception area and the private waiting area also helps to make the spatial scale more comprehensible for visitors, achieved for example by using a warmer colour temperature and narrower light cone for the private waiting area.

Another design parameter in perception-orientated lighting design is the consistency of room patterns and light patterns. A large white wall represents a uniform, clear shape. However, downlights on the ceiling are often found in front of walls in foyers that create characteristic light cone contours on the wall, thereby negatively impacting the clarity of the wall. As a result the luminance curve creates a new pattern where the upper part of the wall remains dark and the lower part appears bright – separated by a highly conspicuous row of parabolas. In this case the room pattern and light pattern show no consistency because an antithesis is created between the uniform wall material and the bright-dark contrast, thereby hindering the readability of the room. Wallwashing creates a different impression. The uniform distribution of brightness from top to bottom and along the complete wall creates a distinct uniformity of the space and light and supports orientation in the foyer. Entrance halls with wallwashing also radiate a greater degree of calmness because no bright-dark transitions on the walls fight for attention.

Vertical illuminance: illuminating what the eye sees

Our impression of brightness comes from the luminance levels in the field of vision. If the line of sight of the human eye is targeted to the front, vertical surfaces in foyers gain high relevance because they account for a high proportion of the field of vision when a building is entered. The combination of bright material colour and lighting creates a correspondingly bright impression in the space that contributes decisively to the overall atmosphere of the entrance area. During the planning phase of entrance areas it is a good idea to go through a building as a fictitious visitor, assess which surfaces dominate the field of vision and pay special attention to these in the lighting design. In foyers, the wall opposite the entrance gains high importance because it is located within the visual axis when the building is entered. The light effect also has an impact on the exterior, and when the building is approached it can create a very prestigious impression.

If visitors to the foyer then go to an information area or coffee counter, it is also recommended to work with bright vertical surfaces here as well, in order to guide attention to these locations. When using high quality or unusual wall elements in particular, suitable lighting is able to emphasise the inherent quality of their materials, for example by using grazing light on raw natural stone. Vertical illuminance is also ideal for emphasising pictures or building columns as interior elements. A narrow accentuated and optionally oval light cone, planar wallwashing or striking grazing light can be used according to the size, proportion and material.

Achieving high economy with efficient lighting tools

Because foyers present many different lighting tasks, high efficiency with regard to the desired light impact as well as investment, operating and maintenance costs can only be achieved if the technology is optimally matched to the specific situation. Lighting technology that should fulfil several tasks simultaneously can only lead to a weak compromise and often demands the limiting of one or several factors. For example, a spotlight with wide light distribution is suitable for efficiently accentuating a large picture, if however wallwashing is desired for the far face of the foyer, this photometric system is not suitable because it does not enable a uniform distribution of brightness from the top of the wall to the bottom. As a consequence and to achieve maximum efficiency, ERCO has been working for decades with a highly differentiated programme of lighting tools.

The product ranges can be efficiently used for various situations thanks to a consistent luminaire design with various light distributions, lumen packages and light colours. With spotlights, lighting designers also benefit from the flexibility of the lens system. Replaceable Spherolit lenses allow simple adjustment of light distribution in the same luminaire housing, for example from spot to flood or even to an asymmetric wallwash. This gives building constructors the chance to flexibly modify the lighting with subsequent redesigns, new artworks or other furniture in the waiting area for example, and to achieve a long service life.

Winning over with good visual comfort

Merely considering the efficiency of a lighting system frequently only places attention on the economic aspects of the luminaires. It is however equally as important to integrate visual comfort into the lighting design of foyers. A very high luminaire light output ratio often accompanies low visual comfort, and this leads to situations where the lighting is judged to be energy efficient. The lack of visual comfort often causes glare and therefore a low level of acceptance – something that should definitely be avoided. This challenge can be mastered by using suitable lighting technology and luminaire arrangements. The first step towards more visual comfort consists in selecting a narrow halfpeak divergence instead of a wide one, meaning the angle of light distribution at which luminous intensity is 50% of the maximum luminous intensity value. The light cone should also have no stray light, thus minimising the chance of direct glare as well as indirect glare from reflections on room surfaces or furniture. A second step is selecting a suitable cut-off angle, the angle specifying how well the light emission surface is shielded. With downlights for example the larger the cut-off angle between the ceiling and a straight line from the luminaire periphery to the edge of the light source, the higher the visual comfort.

A further aspect of optimisation results from the luminance of the reflector or the anti-glare cone. A black coating generates distinctly less luminance than a matt satin aluminium surface in such cases. The topic of glare reduction should be paid particular attention to in high foyers. Lighting designers can use special double-focus downlights for such applications that feature a precise light cone, good shielding of the light emission surface and a black anti-glare cone. Suitably arranging the luminaires offers further potential to minimise glare and thus achieve high levels of visitor acceptance. Instead of creating a grid, individual luminaire arrangements can be implemented for each spatial situation. Differing wall and luminaire spacing is created according to the specific light distribution – these distributions can be looked up in the planning aids of the luminaire manufacturers. The design of the ceiling also offers diverse options to reduce a view of the luminaires, e.g. with use of lamellae or ceiling channels. An exemplary foyer solution below demonstrates the unity of efficiency and visual comfort for a flat white ceiling.

When light offers a warm welcome. Attractively designing foyers with qualitative lighting design.

The qualitative lighting design focuses on good orientation and a bright spatial impression. The differentiation into reception, table, stairway and wall zones supports readability and therefore improves orientation. Various types of luminaires with wallwashers, double-focus downlights and downlights with oval flood provide optimum light distribution in each case.

When light offers a warm welcome. Attractively designing foyers with qualitative lighting design.

The quantitative lighting design of a foyer aims at achieving minimum illuminance. Functional requirements specify a large circulation area and the zone with the reception below the gallery. Downlights generate uniform brightness as well as striking light cones on the walls. The upper wall area appears dark.

Quantitative and qualitative lighting design of a foyer in comparison

The comparison of a quantitative and qualitative lighting concept for the reception area in the headquarters of a mid-sized company demonstrates the design-, technical- and energetic potential of perception-orientated lighting design. The situation: visitors to the large, two-storey entrance hall find a reception desk and several standing tables with stools. Daylight enters the foyer on one side through the large glass façade, and guests access the seminar rooms on the upper storey via a wide staircase on the opposite side. For quantitative lighting design, the requisite illuminance levels were initially analysed based on the appropriate standards and specific functional requirements. This gave a horizontal illuminance of 100lx with high uniformity for the general circulation areas. Illuminance of at least 300lx was assumed for the workstations at the reception desk. Wide distribution LED downlights arranged in a regular pattern are suitable for efficient lighting with good uniformity. The required 30 recessed ceiling luminaires generate efficiency of 3.64W/m2.

When light offers a warm welcome. Attractively designing foyers with qualitative lighting design.

With qualitative lighting design the floor plan specified zones: wallwashers opposite the entrance, downlights with oval flood light distribution for the gallery and double-focus downlights for the waiting area.

When light offers a warm welcome. Attractively designing foyers with qualitative lighting design.

With the quantitative lighting design a uniform pattern of wide distribution downlights is installed across the ceiling.

Creating orientation and a generous atmosphere with qualitative lighting design

The qualitative lighting design concept on the other hand starts with the general spatial impression for visitors. The wall opposite the entrance is given high relevance for achieving an initially bright and generously dimensioned impression. This wall should receive uniform lighting using wallwashers to emphasise the size of the space and simultaneously support orientation towards the staircase. For discussions at the reception though, the wall behind the desk is decisive for an impression of brightness. Here wallwashing contributes significantly to perception because the homogeneous washing creates a sense of distance and dimensionality. As a supplement, horizontal lighting of the longitudinal reception desk is implemented with oval light distribution from LED recessed ceiling luminaires, thus achieving sufficient illuminance for work tasks. The standing tables in the foyer are highlighted via the directed light and the concentrated configuration of double-focus downlights. The especially good shielding and dark anti-glare cone also help to achieve very good visual comfort in the high foyer. The same luminaires are also ideal for illuminating the staircase to the upper storey with high efficiency and visual comfort. Downlights with oval light distribution are used for the gallery in front of the event rooms, as wallwashing would not be suitable due to the dark wall.

Illuminance at the reception is also at least 300lx in this case with an average of 100lx in the circulation area. The concept can be implemented with only 25 luminaires. With 2.02W/m2, this lighting solution achieves energy savings of 45% compared to a conventional solution using only wide distribution LED downlights. This concept however not only concerns the reduced energy value but equally the additional gain in terms of appearance. The improved orientation towards the staircase is particularly apparent as well as the bright overall impression of the space. A further advantage is the effect of the foyer on the outside. During evening hours the foyer with its twin-storey wallwashing creates a prestigious view of the inside from the outside and gives the façade a transparent effect. The wide-area wall illumination behind the stairs is also ideal for displaying a company logo or artworks for example. With regard to self-presentation, this qualitative lighting design appears more modern and seems to have higher quality than the conventional concept, thereby making a significant contribution to brand identity.

When light offers a warm welcome. Attractively designing foyers with qualitative lighting design.

The differentiated lighting tools used in the qualitative lighting design enable higher efficiency. The number of luminaires and connected load are economically superior to the quantitative lighting design. The result is lower energy requirements per area.

Summary: sufficiently welcoming with light

With the change in perspective from a quantitative lighting design aligned to standards to a qualitatively-oriented foyer design, this more attractive lighting solution not only achieves added value for visitors but also cuts investment and operating costs for the building owners. When entering the foyer the lighting of the walls with e.g. wallwashing is an important strategy for a bright spatial impression. The subdivision into zones such as information, circulation area and waiting area in foyers helps to dispense with inefficient generalisations that assume maximum requirements for illuminance and homogeneity, and to develop an efficient as well as attractive solution in each case. To achieve high acceptance levels with visitors it is recommended to pay attention to good visual comfort by using narrow light distributions as well as luminaires with good glare control. Because foyers communicate the first impression of a company or establishment, lighting can be ideally used as a medium not only for visualising functions and offering orientation but also for understanding light as a tool for emphasising the brand appearance.

Lighting recommendations for foyers

- Accentuating important elements such as the reception, stairway and elevators aids orientation.
- Wallwashing creates a brighter and more generous impression of the space.
- Illuminating the wall opposite the entrance creates spatial depth and contributes importantly to the external impression of the foyer.
- A specific lighting concept for waiting areas using accent lighting is able to create a private atmosphere within a large foyer illuminated with general lighting.
- The accent lighting of objects or areas should have a contrast of at least 1:5 to the surroundings to be distinctly perceivable for the eye.
- It is recommended specifically in high foyers to pay attention to good visual comfort, to use narrow instead of wide halfpeak divergence and avoid high cut-off angles, thereby avoiding direct glare caused by the luminaires.
- Energy consumption can be optimised by using light control and daylight sensors and lighting levels can be optimally matched to day and night situations.

 
When light offers a warm welcome. Attractively designing foyers with qualitative lighting design.

Dr. Thomas Schielke

Dr. Thomas Schielke studied architecture at the Darmstadt Technical University, Germany. He has worked for more than ten years as editor for didactic communication at the luminaire manufacturer ERCO and is co-author of the textbook "Light Perspectives: Between Culture and Technology".