Lighting a façade - what should be considered?
Light shapes our view, our opinion of a space and even how long we will stay.
A lighting scheme can influence whether we will come back again, it helps shape our urban space in the hours of darkness, bringing out the materials, textures & finishes of the surfaces around us. New technologies have enabled lighting to be considered earlier in the design process allowing for the luminaires to be integrated providing a seamless & integrated solution so that by day the building is seen in full view and then by night the luminaires and the lit effect brings the building to life.
At acdc we always discuss 5 fundamental considerations when it comes to lighting a façade - context, contrast, colour, control and people. So let's start with context.
Lighting external façades brings value and interest to an urban environment - it brings people into a community and thereby brings investment. Architectural lighting can include a complete plaza or a street, it is not always only a single façade. By considering the role the building(s) play in the community and how one façade is balanced with another, we are able to create point of reference within an urban environment, using light as meeting points, points of destination, communal space in the hours of darkness.
Architectural lighting should be seamlessly integrated to enable a building to be seen and appreciated during the day and then bring the building to life in the hours of darkness.
The specifier should consider the mounting options available to illuminate the building and consider the use of the building. How do people use it, interact with it and how should the external lighting consider this?
Next we will discuss contrast:
Urban design should enable key points of interest to be focal points at night, careful planning with the integration of architectural lighting to a space will encourage people to spend more time outside, to explore, experience, enjoy and play.
It is the play of light and shadow and the ratio between the two that will shape a project, will a façade be lit with a uniform wash of light by fittings that are offset, or have surface mount linear fittings grazing up the façade framing the height, colour and texture? How will this balance with the perimeter public lighting or lighting to the urban streets?
The lighting integrated into a façade can also be a key ingredient in the lighting to the public realm space below and around. Through backlighting or integrated lighting, the direct and diffused light provides a positive contribution to the public realm illumination.
So what should be considered when it comes to colour?
Again, consideration should be given to the context of the building with regards to colour being applied. A review of the adjacent buildings is key to ensure that a competition does not ensue. The type of building and its use should be considered to decide whether colour should be applied at all. Think of the material specification and finish of the building and how light can enhance this not eliminate it.
Looking at the different types of finish; for an historical building the finish is often matt in a warm coloured stone - emphasising the architecture using a warm colour temperature of 2700K or 3000K. Consideration can also be given to a dynamic white solution enabling the specifier to pick ‘the right white.’
Modern building techniques have meant that the colour of the light is very important in drawing out the colour and finish of the façade. An example is CorTen steel (weathering steel) with the rusting orange textured finish, but in the hours of darkness if it is not lit it disappears. If warm white light is projected upon the façade the colour and warmth begins to be defined, and if the contrast upon the façade is varied by ‘picking out’ architectural details by using different beam angles then the character is further defined.
Where colour is implemented it can be used to represent an activity, a movement, a special occasion. Bringing a new positive visual impact to an urban space.
If a façade is glazed further investigation should be given to whether it is clear, opal or frosted in some way, helping to determine a suitable lit effect. It may also be suitable to consider how the internal lighting of a building can express the external appearance at night. Thereby saving on installation costs, energy consumption and further maintenance costs.
Ok so we've discussed context, contrast and colour, now let's look at control of the lighting scheme.
Control doesn’t have to mean blue to red to yellow over three seconds! It can be the play of the intensity of the light, a change from warm white to cool white. Having only a few defined scenes of light that change automatically over a year during the seasons.
The control of the lit effect can enable the viewer to have a new experience, a different view of the space around them because of how it is controlled, changing the identity and thereby the look and feel of a space each time they return.
Control can mean the slow movement of light that responds to the movement of people, or changing the colour to respond or pay respect to a global charity day.
How the external space is used at night can inform the control of lighting, as the hours of darkness grow into the early hours of the following day that not all of the scheme is still on, and this control may differ from weekdays to the weekend too as the use of the external space differs.
And last but absolutely not least it's important to consider people and how they will interact with the space.
People are at the centre of any new lighting design to enable them to have new positive shared experiences in the urban space.
Consider how people will interact with the space that is being lit, their view point so that they do not see into the light source, the view internally out and vice versa. Fundamentally it is how the light attracts them back to a space, to make them feel safe and at ease in the external environment.
Light can define a personal space without the physical visual noise of other object. Through integrated lighting an open public realm can come to life in the hours of darkness, allowing people to be alone, sit with friends, enjoy the view around them all whilst feeling secure and safe in the environment around them.
Author: Dan Hodgson, acdc Lighting Applications Director