DaylightFactor (EN 17037) Extension


The EN 17037 standard (in UK: BS EN 17037:2018 Daylight in buildings) proposes to use the daylight factor to assess the natural light supply in a space. For the UK variant using the "UK National Annex", see DaylightFactor (EN 17037/UK). This extension is designed to follow the recommendations of the original standard:

As this computation is based on the same process as classic DF calculation, we recommend that you get familiar with DF: Daylight Factor calculation.

DL-Light extension FLJ daylight factor en17037 Sketchup model snapshot image

How To Use DaylightFactor (EN 17037) Extension

Note: the WELL standard translates thresholds in lux of the standard EN 17037 in foot-candles. To display the various thresholds (palettes, reports) in foot-candles, use the option "Display in lux or foot-candle" in the preferences. Only the display is modified, the calculations are identical regardless of the option selected.

  1. Open SketchUp model. Follow recommendations to prepare your model for DL-Light calculations.

  2. Open DaylightFactor dialog from toolbar df_dialog_icon or menu option Extensions -> De Luminae -> Daylight Factor (EN 17037) -> Activate extension and enter the parameters of the calculation.

    DL-Light extension FLJ daylight factor DF en17037 General tab

    Fields description:

  3. Define materials characheristics.

    Since calculation is done with validated Radiance tools it is necessary to 'attach' physically based material to each layer in SketchUp. Note that materials should be defined with their solar reflectance and transmittance.

    The tab to choose materials:

    DL-Light extension FLJ daylight factor en 17037 DF Materials tab

    Materials panel consists of two main parts:

    To attach a material, select in the table layer(s) and either double-click on the chosen material in the tree or select the material in the tree and press Attach/Detach button.
    To detach from the layer(s), select it and click Attach/Detach button.
    To revert all layers to previous state press Revert button.

  4. The palette of false colors uses the thresholds of the standard. It is possible to change the different colors.

    DL-Light extension FLJ daylight factor DF en17037 palette tab
  5. After all data are entered in DF dialog, select one or few surfaces and press Render or run_selected button.

    As the glazing is kept for this calculation, it may be practical to use the DL-Light select by layer dialog DL-Light select by layer to select the areas to be calculated.

    DL-Light extension FLJ daylight factor en17037 SketchUp selection

    Calculation time depends on number of selected surfaces, level of sensors details and model complexity.

  6. When results are imported, selected surface will have appropriate false colors and Palette is opened.

    DL-Light extension FLJ daylight factor en17037 SketchUp result imported

    Surfaces illuminated primarily by a horizontal light source receive this watermark: DL-Light daylight factor en17037 watermark

    DL-Light extension FLJ daylight factor en17037 result horiz source light
  7. Results analysis.

  8. For further calculations in the same model:

    DL-Light uses a calculation cache algorithm. It automatically detects if a surface requires recalculation or if a previous result can be reused. By default, the cache keeps the information of the last 10 calculations (value configurable in the preferences).

  9. Archiving results:

    DL-Light allows to archive all the results of a calculation: reports, textures and calculation steps (exported Radiance model, weather file, ...). This archive can be reloaded on the model, subject to using exactly the same model as during the calculation.

    See the page Archiving results for more informations about this feature.

    See the page Comparison of results for more informations about comparison of archives.

  10. Snapshots:

    Current SketchUp model view with imported results can be exported with palette snapshot_with_palette_icon or without palette snapshot_icon to png format. To explore created images user can open folder where they are saved open_snapshot_folder_icon.
    This option is not supported in trial version of the extension (see license information).

    DL-Light extension FLJ daylight factor Sketchup model snapshot image