How is the provision of daylighting design measured?
EN 17037 sets a minimum level of performance that must be achieved for each of the four areas of daylighting design, to provide flexibility for architects and designers, while also making the standard useable and understandable.
As well as the minimum recommendation, it also gives two further performance levels: medium and high. Users of the standard are free to select the performance level that best relates to the building design and proposed building use.
A simplified and detailed method is available with which to assess each design area. The standard harmonises the evaluation of daylighting, but takes into account national and local conditions so that solutions are appropriate and specific to each project.
Designing for daylight and building occupant comfort
Daylight provision, or illuminance levels, allow users to carry out tasks and play a part in determining the likelihood of artificial lighting being switched on. Assessment can be via either climate-based modelling or daylight factor calculations.
Building users should have a large and clear view of the outside. EN 17037 considers the width and outside distance of the view, as well as landscape ‘layers’ (sky, landscape and ground). The view should be perceived to be clear, undistorted and neutrally coloured. Width of view can be established via a detailed or simplified approach. Outside distance and number of layers are each measured by a single approach.
Calculating access or exposure to sunlight is a comfort and health factor for building users. Daily sunlight exposure can be established through detailed calculation or table values.
As its name suggests, prevention of glare is concerned with removing the probability of glare for building users, especially those who do not choose where they sit. It uses a detailed calculation of daylight glare probability (DGP) or a standard table of values for sun-screening materials.
VELUX Commercial specialises in offering daylight solutions for commercial buildings. Contact us to find out how our rooflights can improve daylighting in your project. Find out more about why the standard was created, and what building types it applies to.