Calculation of BREEAM Daylight requirements

BREEAM is an assesment method and agency for the certification of buildings sustainability. It defines requirements that building projects should meet to get a sustainability certification.

Among the various requirements, some are grouped in a particular category called "HEA 01 Visual Comfort". Visual Comfort requires the calculation of 2 specific criteria called:

DL-Light helps the designer to calculate these indicators directly inside SketchUp.

As this calculation is based on the same process as other daylight autonomies, we recommend that you get familiar with general Daylight Autonomy calculation.

We will not go in depth in the definitions of these criteria. For details about them, we recommend that you check the abundant documentation provided by BREEAM.


Principle of calculation

The requirements are based on the following calculation :

The general procedure is complex and DL-Light provides a simple interface to perform these calculations and explore results.


How to calculate BREEAM Daylight requirements

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

  2. Open Daylight Autonomy dialog from toolbar da dialog icon or menu option Extensions -> De Luminae -> Daylight Autonomy -> Daylight Autonomy Calculation and enter the parameters of the calculation.

    DL-Light extension daylight autonomy BREEAM DA 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 daylight autonomy BREEAM DA Materials tab

    Materials panel consists of two main parts:

    To attach a material, select in the table layer(s) and either double-click on required 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 false color palette is updated for BREEAM requirements.
    The 4 default colors are set to allow a readable display directly in the SketchUp model.

    DL-Light extension daylight autonomy BREEAM DA palette windows
  5. After all data are entered in DA dialog, select surfaces and press Render or run_selected button.

    DL-Light extension daylight autonomy BREEAM DA Sketchup selection

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

  6. Results analysis.