Home » BIM and Building Design » Architectural Lighting: Managing Light Effects

Architectural Lighting: Managing Light Effects

Techniques and tips for developing an impactful architectural lighting project and controlling lights with 3D modeling software

Light has a profound influence on the perception, experience, and functionality of architectural spaces. Let us remember that Le Corbusier, master of rationalist architecture, defined architecture as “the masterful, correct, and magnificent play of masses brought together in light.” He also added: “Our eyes are made to see shapes in the light; light and shadow reveal these shapes; cubes, cones, spheres, cylinders, or pyramids are the great primary forms that light reveals to advantage; the image of these is distinct and tangible within us without ambiguity. This is why these are beautiful forms, the most beautiful forms. Everyone agrees on this, the child, the savage, and the metaphysician.”

This approach shows how even Le Corbusier considered light as a grand device to enhance the beauty of pure architectural forms.

In this article, we will see how to enhance your projects by making wise use of artificial light and controlling the outcome of design choices through a BIM architectural design software.

Architectural lighting project | Render created with Edificius

Architectural Lighting for Building Facades

As mentioned in the introduction, light has the power to emphasize architecture. Therefore, it is essential that architectural lighting is preceded by a real project and takes shape following evaluations, detailed analysis of the context, and the desired outcome.

It is not enough, in fact, to use a large spotlight on the facade to achieve the best result, but it is necessary to understand first of all which elements we want to enhance, where it is possible to position the lights, which type to use (grazing, frontal, warm, cold, etc.) to achieve the imagined effect. These choices will determine very different effects and results, and it is necessary to study and predict them already in the project phase. For example, if the facade is characterized by a textured or irregular surface (stone cladding, bricks, etc.), grazing light can emphasize the texture and create a very pleasant, three-dimensional, and impactful result. Or, if you choose to use frontal lights to uniformly illuminate the building, it is necessary to verify directly on-site where it is possible to position them and at what distance, based on the constraints and characteristics of the location. In fact, it is not always possible to position the lights where we have hypothesized, perhaps due to the presence of roads, buildings, and other physical impediments.

To approach a lighting design project, it is first necessary to identify the main viewpoint towards the building or the area to be illuminated. It is a good rule to avoid this direction coinciding with that of the lighting if you want to avoid a flat effect: the direction of light, in fact, can emphasize or flatten the details and even be annoying for users (glare phenomena that can be avoided by increasing the installation height, directing the maximum intensity of the projectors at angles below 70° relative to the vertical downward, and increasing the background ambient lighting).
To determine the amount of light for outdoor lighting, there is a combination of factors to consider such as:

  • luminance;
  • reflectance;
  • illumination.

In the field of architectural lighting, the brightness of the surrounding context and the type of area, known as ambient brightness, play a fundamental role. To avoid over-illumination and light dispersion, it is essential to follow specific regulations, which include recommended luminance levels based on average and maximum illumination for different areas, ranging from natural areas outside cities to more densely illuminated urban centers. The ratio between average and maximum luminance determines the subject’s contrast, known as luminance contrast. For example, if a small portion of a building facade is illuminated with a luminance of 1 cd/m², the details will be barely perceptible; increasing the luminance to 5 cd/m², the effect becomes more evident. This ratio also takes into account the amount of light reflected by surfaces. For example, if a facade is made of red bricks with a reflection index of 0.3 and another part is white with an index of 0.9, and they receive the same amount of illumination, there will be a contrast ratio of 1:3. To facilitate planning, there are recommended illumination values for the most common materials, which can be used as a guide during the preliminary design phase, using a white light source.

Architectural Lighting Project | Render created with Edificius

Architectural Lighting Project | Render created with Edificius

It is important, already in the project phase, to create realistic simulations that reproduce the effect of architectural lighting. With a 3D BIM modeling software, you can achieve these results easily. Model the building in 3D, add textures and materials, insert light points, generate renders and realistic project views, or navigate the model in real-time to verify the validity of your choices. Make changes to the model and check the result to bring it closer to the project idea.

You can insert lighting fixtures and choose them from a rich catalog with many models from the most well-known and iconic brands. For the lighting fixtures, you apply the light point, choosing the type:

  • spotlight;
  • point light;
  • area light;

the light color, lumens, temperature (Kelvin), and type:

  • incandescent;
  • halogen;
  • LED;
  • fluorescent;
  • etc.

The images in this article are all created with a 3D BIM modeling software and show you the type of effect you can achieve with minimal effort. Moreover, the below video shows you how to insert light points into your 3D model.

Evaluations regarding the light source should include:

  • position;
  • beam angle;
  • power;
  • temperature (warm light, cool light, or even RGBW colored light);
  • distance from the object;
  • tilt (angle of incidence);
  • device quality (suitable for outdoor use, waterproof, drivable, etc.);
  • dimming capability and brightness management.
light temperature

LED light temperature

Architectural lighting techniques for building facades can vary and depend on the desired effect, architectural design, and surrounding environment. Below are some of the most common techniques explored.

Projection Lighting

When illuminating building facades from a distance, it is important to consider how to strategically position the lighting fixtures. If illuminated directly from the main viewpoint, buildings risk appearing flat and lacking depth. Therefore, it is advisable to position the fixtures with a lateral tilt relative to the main viewpoint, creating sharp shadows that add depth to the facade.

It is essential to uniformly illuminate the entire building to make it stand out from the surrounding context. All elements such as the roof, chimneys, walls, trees should be involved in the lighting. Often, it is necessary to integrate main projectors to avoid irregular lighting effects that can make buildings look suspended in space. Fixtures can be hidden behind existing structures, recessed into the ground, or discreetly installed.

Facades with vertical elements, typical of Gothic and classical architecture, can be emphasized by positioning fixtures on the sides of the facade and using medium beam projectors. However, it is important to consider that oblique lighting can create very sharp contrasts, so it is advisable to integrate a fill light from the opposite direction to soften the overall effect.

Accent Lighting

When illuminating a sculpture or decorative detail of the building, it is essential to create an effect that highlights the shapes, making them stand out from the surrounding context. The main difference between natural and artificial lighting is that natural light always has a top-down direction, while artificial light can come from different directions, often from bottom to top. This means that shadows cast by artificial light will be different from those of natural light, creating a distinctive nighttime appearance and a completely unique building reading plan.

The first step is to establish the main viewing position. Subsequently, the main lighting usually proceeds from an angle of about 45°, if possible, supplemented by a fill light source from the other side. A more pronounced three-dimensional effect can be achieved by adding backlighting, taking care to avoid glare for observers from the main viewing position. When illuminating an object visible from different angles, it is advisable to light it from three directions, giving more emphasis to one of them.

Artworks with light colors are more visible when they are lighter than the background, while dark statues, such as bronzes, stand out better with a silhouette effect.

Shadows cast by an illuminated object can significantly contribute to the overall effect. By using light sources of different colors, interesting light and color games can be created. However, it is important to balance the light intensity to avoid overly sharp shadows that could compromise the final appearance.

In entertainment venues, it is important to avoid excessive use of shadows, as they could reduce people’s sense of safety in the space.

When illuminating facades with balconies or galleries, projection lighting is often preferred to avoid strong shadows. However, if the space in front of the facade is limited, additional lighting can be placed on balconies or incorporated directly into the building to create desired shadows.

Any technical constraints or specific requirements often require a modified distribution or intensity of the light beam. The use of additional optical components can be useful to adjust the light beam and achieve the desired result, as well as the ability to adjust the light intensity through a dimmer on the projector itself.

render architectural lighting with Edificius

Architectural lighting render created with Edificius

Grazing Light

Try this experiment yourself: at night, outdoors, shine a flashlight directly onto a wall of bricks – you will see the color and shapes of the bricks. Now place the flashlight near the building’s surface and direct the light at a grazing angle (from below or above, positioning the light source almost parallel to the wall’s surface) – you will also notice the texture. This technique, known as “grazing,” is effective in showing not only the texture of the walls but also in enhancing the shapes and adding depth. It also simplifies the lighting of architectural details. An advantage for inhabited or frequented buildings in the evening, such as offices, hotels, or villas, is that this technique allows only a small amount of light to enter the building, avoiding discomfort or nuisance for its occupants.

A more conventional approach to “wall washing” involves uniform lighting across the entire facade. By installing fixtures at regular intervals – or in a continuous row in the case of linear profiles – the walls are gently “washed” with uniform light. This soft, glare-free lighting generates visual interest and, in many cases, provides general lighting in the area through reflection.

The distance between fixtures, especially in linear profiles, and the selection of the appropriate beam angle play a key role in determining whether a wall is adequately illuminated or not. Separate lines may be desired to communicate and define a rhythm on the facade.

“Wall washing” usually requires a large number of low-power fixtures compared to those used for long-distance projection. Where possible, fixtures should be recessed or hidden.

Guiding Light

To indicate pedestrian (but also vehicular) paths, it is possible to use ground-recessed lighting fixtures. These lighting devices can guide individuals along a specific path, drawing attention and indicating the direction to follow. It is advisable to use low-power lamps for this purpose to discreetly emphasize entrances, pathways, intersections, steps, and seating, while also avoiding light pollution. During the night, they provide a clear visual guide, while during the day, they continue to serve as a visual reference.

Light fixtures recessed in the wall represent an effective alternative to those in the ground, especially in areas with level differences. It is necessary to provide housing structures for the fixtures and supply electrical power. The shape of the fixtures can be chosen according to the context, whether circular, square, or rectangular. Wall-recessed fixtures are generally less exposed to vandalism compared to the bollards often used to illuminate paths.

There are different types of fixtures recessed or mounted on the wall, which can be equipped with various combinations of colored lights and directional grids to create diverse lighting effects. It is also important to consider directional windows to aim the light beam horizontally. The selection of fixtures should take into account their aesthetic impact in the surrounding environment.

Achieving a final bright, warm, and uniform lighting effect, especially in transit areas, is fundamental. The color of the light should be natural and should not cause glare to passersby. Attention should be paid to the surface temperature of the fixtures, especially considering the possibility of children touching them. Therefore, it is advisable to use fixtures with low temperatures to avoid this risk.

Light Effects

The tone of architectural lighting, which can be welcoming or formal, intimate, relaxing, or celebratory, largely depends on the emotional response elicited by the light effect used. Therefore, the designer has a powerful tool, light, to redefine the appearance of architecture or natural landscapes.

In the outdoor context, lighting should not simply replicate the daytime appearance of the building or subject, as the direction of daylight is generally opposite to that of nighttime. Effective installations leverage these differences rather than trying to emulate them.

An example of lighting designed to create an effect is column lighting. A row of columns can be illuminated frontally, laterally, or from behind, creating a silhouette effect. It is preferred to use light to highlight shapes rather than flatten the overall appearance.

The designer must consider the visual impact and the privileged point of view. A series of lighting techniques can be used, including light play, shadows, and colors; variations in mounting position or height; changes in design and fixture type; and adjustments to localized lighting. A site visit is often essential to establish the main viewpoint, assess surface textures, and ensure that the lighting harmonizes with the surrounding environment. Glare or light dispersion that can be annoying or dangerous should be avoided.

For colored light, a common solution is the use of colored lamps. Dynamic systems can be used to change color, such as RGB LEDs controlled by DMX electronic devices, allowing for a variety of programmable and adjustable color options.

Photorealistic Rendering for Architecture (2)

Light in Architecture

Architectural lighting creates a luminous harmony between the illuminated object and the context, enhancing architectural details, form, and beauty.

There are two aspects to consider when illuminating a building: the functional factor and the emotional factor. The functional factor refers to technical aspects: the positioning of lighting fixtures, the amount of light emitted, the characteristics of the surface to be illuminated, the type of lamps, and color rendering. The emotional factor speaks to color play, the size of the light beam, the contrast created by architectural elements, and color temperature.

In addition to functional and architectural lighting, there is a third type that serves a promotional purpose. With light, different results can be achieved, such as:

  • enhancing architecture;
  • highlighting the building;
  • creating suggestive atmospheres and empathy with the observer;
  • improving the use of spaces in the absence of natural light;
  • increasing perception of safety during nighttime hours;
  • highlighting a commercial brand.

Various lighting techniques allow for different outcomes. Here are some of the variables at play and some secrets to managing them.

Surfaces

The amount of light we direct towards the monument or building is less relevant than the light reflected. Visual perception depends on the type of texture and the reflective capacity of the surface.

For example, darker and rougher surfaces require more lighting than lighter and smoother ones. The same applies to color, as a crucial aspect is the color absorption index. Monochromatic light sources or those based on a limited range of colors will only show some nuances of the structure. For instance, using a low-pressure sodium lamp (which emits a yellow monochromatic hue) on a red surface would be ineffective as it does not emit red wavelengths, making the visual effect almost imperceptible. However, illuminating a surface with a dominant color, such as green foliage on trees, with corresponding light will result in color saturation, enhancing the natural shade of the subject. For accurate color rendering, “white” light sources covering the entire chromatic spectrum are needed. In addition to reflectance, it is important to consider the specularity of the building surface. Matte surfaces reflect light uniformly in all directions, ensuring good luminance when lit from below. However, reflective surfaces like marble and stainless steel can pose issues when ground-installed spotlights project light rays upwards, away from the observer.

Light Sources

The most common lamps in architectural lighting are high-intensity discharge (HID) lamps such as metal halides and high-pressure sodium. However, these lamps are not suitable for dimming and, in the case of sodium, do not allow for accurate color rendering. Small tungsten halogen lamps, with their excellent color rendering and bright light, are still used, but due to their poor efficiency and short lifespan, they are often replaced with LEDs. Linear fluorescent lamps offer high luminous flux and a wide range of color temperatures, but due to their size and light dispersion, they are not optimal for direct projection; they are more suitable for wall washing and as guiding lights. Currently, LEDs are the most commonly used lamps, thanks to their continuously evolving performance and cost-efficiency. Their unique characteristics, such as instant-on, high efficiency, compact size, long lifespan, reliable performance at low temperatures, good color rendering, and color management/dimming, make them ideal for most applications. Furthermore, the luminous flux of LEDs is directional, allowing for the design, techniques, and optical materials to control light distribution and maximize performance.

Color Rendering

Within “white” light, emitted by fluorescent, halogen, metal halide, and LED sources, there is a variation in color temperature that will influence the overall appearance, making it warmer or cooler depending on the temperature. A simple and reliable method is to use warm light sources with warm-colored materials and cool light with cool-colored materials. For example, one could choose to illuminate a red brick with high-pressure sodium lamps (emitting a yellow tone with a limited spectrum) with a color temperature of about 2000K to achieve an overall warm effect, while it might be inappropriate with metal halide lamps with a color temperature above 5000K. Additionally, there is a Color Rendering Index scale, expressed as “CRI” or “Ra” (from 0 to 100): a higher value indicates more accurate color rendering. Lamps with a high CRI value, exceeding 80, will ensure good color rendering, making the scene more natural, while lamps with low color rendering will distort some colors, resulting in an overall unnatural appearance.

 

Edificius
Edificius