The International VELUX Award is a competition for students of architecture that runs every second year. We challenge students from all over the world to work with daylight as an ever relevant source of light, life and joy. The award is one of the most important global student competitions of its kind.

Submission is now closed. The jury will review the projects in July and the regional winners will be announced in August.

Evaluate and improve your project with Daylight Visualizer

It's important to consider daylighting conditions in the early phase of a building design. Daylight in buildings is strongly influence by the envelope design, as well as the proportions of the building geometry, the context and surroundings on the building site. Daylight Visualizer is a free professional tool for daylight analysis allowing you to do just that!

"Daylight Visualizer is a powerful tool to develop ideas for natural light in buildings. The integrated process between design and daylight simulation has enabled to refine the experience of daylight in the interior spaces in a way that was previously impossible"

Andreas Michelsen, CCO Architects

In Solhuset, a kindergarten project in Denmark, Daylight Visualizer was used to validate the daylight conditions during the early phase of the project. This enabled the architect to make significant improvements to the daylight quantities and distribution in key rooms were an initial analysis showed that daylight levels would be too low.

While not adding any new window to the design, the architect was able to include a series of small refinements such as the position of windows and the lining construction of windows. This resulted in a better balance and distribution of daylight in the rooms and circulation areas of the building, as well as higher daylight levels in key activity rooms.

Daylight factor simulation before (above) and after (below) design changes to the building envelope.

Daylight factor (DF)

The daylight performance of the building was evaluated with the daylight factor (DF) method. Daylight factor is a daylight availability metric that expresses as a percentage the amount of daylight available inside a room (on a work plane) compared to the amount of unobstructed daylight available outside under overcast sky conditions (Hopkins,1963).

Drawing showing the values measured by the daylight factor method (simultaneous reading of the internal and external (unobstructed) horizontal illuminance levels).

The key building properties that determine the magnitude and distribution of the daylight factor in a space are (Mardaljevic, J. (2012)):

  • The size, distribution, location and transmission properties of the facade and roof windows.
  • The size and configuration of the space.
  • The reflective properties of the internal and external surfaces.
  • The degree to which external structures obscure the view of the sky.

The higher the DF, the more daylight is available in the room. Rooms with an average DF of 2% or more can be considered daylit, but electric lighting may still be needed to perform visual tasks. A room will appear strongly daylit when the average DF is 5% or more, in which case electric lighting will most likely not be used during daytime (CIBSE, 2002).

Photo-realistic and false colour rendering

The experience of daylight in a room goes far beyond the amount of light received on a work plane and it's therefore important to look into the spatial qualities of daylight and how it illuminates the rooms.

In order to do so, one can perform a series of photo-realistic daylight simulations with perspective views for a range of selected rooms in the building, and under different kind of sky conditions (fx. sunny vs. overcast).

Luminance rendering of a group room for children activities shown in photo-realistic (above) and false colour views (below).

Daylight Visualizer

VELUX Daylight Visualizer is a professional lighting simulation tool for the analysis of daylight conditions in buildings. It is intended to promote the use of daylight and to aid professionals by predicting and documenting daylight levels and appearance of a space prior to realization of the building design.

The difference between Daylight Visualizer and commonly used 3D visualization programs is that it permits you to accurately simulate and quantify daylight levels in interiors, whereas 3D visualization programs only generate images, without information about the quantity and quality of light in a given space. With Daylight Visualizer you can take more informed decisions about daylight performance in your architectural design.

Download Daylight Visualizer for free here and start to optimize daylight in your project!

By Nicolas Roy, VELUX Group