The BREEAM agency has developed a certification method for buildings sustainability. BREEAM publishes requirements that building projects should meet to get a sustainability certification.
Among the various requirements, some are grouped in a category called "HEA 01 Visual Comfort". Visual comfort requires evaluation of the 3 criteria:
The DL-Light Daylight Factor extension allows you to calculate these indicators directly inside SketchUp.
As it is based on the same process as classic DF calculation, we recommend that you get familiar with it: Daylight Factor 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.
The requirements are based on the following calculations:
The general procedure is complex and DL-Light provides a simple interface to perform these calculations and explore results.
"The uniformity ratio calculation, minimum point daylight factor and minimum daylight illuminance can exclude areas within 0.5m of walls. Areas within 0.5m are not considered as part of the working plane for this purpose, although they are included in the average daylight factor and average daylight illuminance calculations. BREEAM
Open SketchUp model. Follow recommendations to prepare your model for DL-Light calculations.
Open DaylightFactor dialog from toolbar or menu option Extensions -> De Luminae -> Daylight Factor -> Daylight Factor Calculation and enter the parameters of the calculation.
Project name - Project name is used during export and for output filename generation. The SketchUp model name is used by default.
Results - Directory where
model will be exported for calculation.
When calculation is started model geometry and resulting files will be saved in 'df_output'' subdirectory.
For SketchUp projects stored on network disk (Windows), see Work on a copy of the model.
Mode - Calculation mode selection:
DF BREEAM - Selection of DF BREEAM type to calculate:
Space - Selection of space type:
For example, if the project is a school, there may be dozens of classrooms and some other spaces such as catering. Set the default space as school, all classrooms will have this type, and then set the specific function for the catering space.
Requirements - Display of the BREEAM requirements corresponding to the BREEAM type and selected space. type.
Grid and units - Sensor grid and units are not displayed:
For BREEAM calculation it is required that sensors are positioned at a predefined distance from the floor surface: 0.85m for industrial spaces, 0.70m for spaces of any other type, To be able to position sensors on this height it is necessary to create virtual surfaces for every space you want to calculate.
Select floor surface(s) in SketchUp model, activate Copy surfaces tool from toolbar Surfaces will be automatically created, you only need to type offset from original surface. For DF calculation default offset is 0.70m, and it can changed at the bottom of SketchUp dialog. To exit from the tool press 'Enter' or 'Esc' button.
Ground albedo - Reflection factor of the ground. Value can be selected from drop-down list or defined custom value in the following dialog.
Location - Building location coordinates. Location can be based on SketchUp model location, current Weather file location or be Custom. Below is dialog for Custom location definition.
A weather file can be selected to facilitate the model
location and determination of time zone.
See page Weather data.
Important : For this calculation, the weather file is only used for location and time zone selection.
Time zone - Display of the time zone used for the calculations.
If a weather file is used, the time zone is defined by this
file. Otherwise, a selection list allows you to
choose the time zone.
Nota: when a model is located in SketchUp, SketchUp proposes a time zone based on the longitude of the place. This value is sometimes wrong, especially for European or Asian countries.
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 of choice of materials:
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.
The false color palette is updated for BREEAM requirements.
The 4 default colors allow a readable display directly in the SketchUp model.
After all data are entered in DF dialog, select surfaces and press Render or button.
Calculation time depends on number of selected surfaces, level of sensors details and model complexity.
When results are imported, selected surface will have appropriate false colors and Palette and Report are opened.
BREEAM results are imported into the SketchUp model. They should be interpreted differently than other DF results.
The calculated surfaces are unicoloured, according to the criteria satisfied by the surface.
DF BREEAM report
The top part of the dialog contains information about DF type.
Below is the part with two indicators which show if BREEAM requirements are satisfied for the project. Upon hovering over these indicators, information about percentage of total area with acceptable average DF and uniformity is displayed.
If an indicator is red, the requirement is not satisfied. If it is green, it is satisfied.
Lower part of the window is an interactive table where user can explore results for each surface.
For more description and functionalities of report, see page Report dialog.