7.2 Daylighting Reports

This screen provides a number of standard daylighting performance reports. Choose which report you would like to view by selecting it in the pull-down menu located at the top of the page. The LEED v4 metric will require an additional ASE calculation that will happen automatically upon selecting this report before the results can be displayed.

The Copy Image button can be used to copy whatever report is currently displayed to the clipboard which can then be directly pasted in any other MS Office document such as Word or Powerpoint. To paste into other formats, first paste into the selectable cell to the upper right of the report and then copy from there.

The Print button will initiate a print dialog for the currently displayed report.

The Back button will return the user to the Daylighting Results page.

The View pull-down menu allows the user to choose to view the report for the entire space or for daylighting zones individually. The hourly workplane illuminance plot and performance metric results will update when the viewed zone is changed. The workplane plots remain the same as they show performance results for the entire space anyways, including all zones.

The View Zone Diagram button can be pressed at any time to pull up a diagram of the daylight Zones.

The upper Space Summary and Metric Results section of all the reports,provides general space and facade information, intended to be complete enough to replicate/verify the design. An isometric of the space and orientation compass are shown in the upper left. Adjacent to this are Space Properties that list the general dimensions of the space and the reflectance of the various surfaces in the model. The Fenestration Properties table lists all fenestration for each surface orientation. It summarizes the surface areas, internal window-to-wall ratios (WWR), average glazing transmittance and any window treatments and control strategy for that facade. If more than 3 different window control zones exist for a facade it will be indicated in the final More… column. A total Window-to-floor area ratio (WFR) is also included at the bottom of this table. The Performance Metric Results section list the prerequisites and display the overall metric performance for the report type chosen.

The lower Design Performance section of the reports provides various forms of annual daylighting performance charts and plots. An Hourly Average Workplane Illuminance chart on the lower left of all reports shows the average illuminance for the space (or Zone selected in the View pulldown menu) throughout the day, for sunny and cloudy conditions, and for three representative seasons of the year (winter, fall/spring, summer). The two plots to the right of this chart are different for each report and described in the report sections below. The Design Suggestions at the bottom of the report remain the same for all reports and are based on the SPOT Daylighting Performance assessment methods. There are 5 categories of design suggestions given, these are: Glare, Uniformity, Quantity, Control, and Shades. The suggestions will typically give a good assessment of the design and good guidance but they are not fool proof. Daylighting metrics are currently undergoing much development and research and the metrics and potential design guidance are being refined regularly.

The following metric reports are available:

SPOT Daylight Performance – This report uses a combination of metrics to assess daylighting performance, utilizing Daylight Saturation (DS), Daylight Excess (DE), a 75% spatial uniformity threshold, and Daylight Autonomy (DA).

This report includes several prerequisites: 1) the grid spacing must be 5ft or less and 2) the simulation parameters must be equal to a M, M, H radiance parameter setting (Medium Quality, Medium Detail, High Variability) and lists Months and Times as addition potential prequisites. Depending on the application, certain months and timesteps may be required.

Next to the prerequisites is a Daylight Excess, Autonomy, and Saturation Coverage plot that summarizes the spatial coverage of the metrics. Vertical lines on this plot indicate recommended thresholds for a typical work (office / class / lab / retail) environment. For Daylight Excess (DE), a recommended goal for critical visual environments is to have <5% of the workplane recieve excessive daylight (10x the target illuminance) for less than 10% of the time. For less critical visual environments, a target of <10% of the workplane recieving excessive daylight for <10% of the time is recommended. For Daylight Saturation (DS), it is recommended that more than 75% of the workplane receive sufficient daylight. If the DS is 40% or greater this is considered 'sufficient' daylight quantity, 60% or higher is considered 'good', 80% or higher is considered 'great' daylight, and if 90% of the space achieves a 90% DS this is a nearly full daylit as possible and is considered an 'excellent' daylight contribution or fully daylit. For Daylight Autonomy (DA), if an >80% DA is achieved for more than 75% of the space, the space can consider on/off lighting controls with only a minimal penalty to energy savings. The grey box on the right of the report gives a general rating for the daylit space that is a function of the glare (DE), uniformity (DS ratios, 75% coverage), quantity (DS), and control (DA and DS) metrics.

The plots on the lower right show the annual Daylight Saturation (DS) and annual Daylight Excess (DE) for the space. The color coding indicates the threshold of DS or DE achieved and match the color in the coverage summary bar chart above. These plots help illustrate distribution of daylight and excess throughout the space and can be seen in the screenshot image above.

LEED v2009 – This report presents the sunny equinox at 9AM and 3PM calculations and the necessary prerequisites for LEED v2009.

There are three prerequisites and a caveat for this report. The prerequisites are: 1) workplane height must be within 10% of 30in (2.5ft, 0.76m) above the finished floor 2) grid spacing must be 5’ (1.52m) or less and 3) Radiance parameters must be set to M,M,H or higher. The caveat is dependant on additional glare measures. Upon selecting this report, the user will be asked if there are additional glare control measures to be used on the windows that were not included in the modeling. If there are, select “yes” and then the metric only requires illuminance to greater than 10fc (~100lux). If not, the illuminance must be between 10fc – 500fc (~100lux – 5000lux).

Next to the prerequisites is an Equinox Illuminance coverage chart that includes a Daylight Excess (DE) report as well simply to warn LEED 2009 users if too much potential glare is detected as the LEED 2009 performance metrics do not account for excessive daylight. The 10fc-500fc illuminance coverage under both a sunny Equinox at 9AM and 3PM must be greater than 75% of the space to achieve 1 LEED point and greater than 90% of the space to achieve 2 LEED points. This will be reported to the user in the Grey report box.

The plots on the lower right show the point-by-point daylight illuminace received on the workplane during the sunny Equinox at 9AM and 3PM requirement. Blue coded cells do not achieve the standard while shades of yellow and orange indicate adequate daylight.

LEED v4.0 – This report presents the spatial Daylighting Autonomy (sDA) and Annual Sunlight Exposure calculations and the necessary prerequisites for LEED v4.0.

There are six prerequisites for this report. The prerequisties are: 1) workplane height must be within 10% of 30in (2.5ft, 0.76m) above the finished floor 2) grid spacing must be 2’ (0.61m) or less 3) the space must contain automated or manual glare control (from pop-up window question) 4) the design-day months must atleast contain the solstices and equinox (12, 3, 6) 5) design day times include sunrise and sunset and have at the most a 3 hour timestep and 6) the Radiance parameters must be set to M,M,H or higher.

Next to the prerequisites is a Spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE) coverage chart. The LEED v4.0 standard gives 2 point for >55% sDA coverage and 3 points for >75% sDA coverage. For the LEED Healthcare Standard the daylighting requirement is a bit stricter and 1 point is given for >75% sDa coverage and 2 points for >90% sDA coverage. Additionally, the standard requires the ASE value to be less than 10% for the entire space to pass. The LEED points awarded, or a “Reevaluate Design” message reporting the violating metric will be displayed in the Grey report box

The plots on the lower right show the Daylight Autonomy and the Annual Sunlight Fraction values for a grid of points in the space at workplane height. These are calculated according to the Spatial Daylighting Autonomy and Annual Sunlight Exposure protocols laid out in the IESNA LM-83 document.

CHPS – Collaborative for High Performance Schools (CHPS) – This report presents the Daylight Saturation and Daylight Excess calculations for the CHPS National daylighting credit standard. This daylighting metric has several prerequisites along with the option of three different performance-based compliance paths. The performance path implemented in SPOT uses the Daylight Saturation (DS) and Daylight Excess (DE) metrics.

There are six prerequisites for this report. The prerequisties are: 1) workplane height must be within 10% of 30in (2.5ft, 0.76m) above the finished floor 2) grid spacing must be 4’ (1.22m) or less 3) the space must contain daylight responsive lighting controls that are either photosensor based or have occupant or education-based strategies 4) the design-day months must atleast contain the solstices and equinox (12, 3, 6) 5) design day times include sunrise and sunset and have at the most a 3 hour timestep and 6) the Radiance parameters must be set to M,M,H or higher.

Next to the prerequisites is a Daylight Excess and Daylight Saturation Coverage plot that summarizes the spatial coverage of the metrics. Vertical lines on this plot indicate recommended thresholds. For Daylight Excess (DE), it is recommended that less than 10% of the workplane recieve excessive daylight, defined as exceeding 10x the target illuminance for more than 10% of the time. For Daylight Saturation (DS) it is recommended that more than 75% of the workplane receive sufficient daylight. If the DS is 40% or greater this is considered ‘sufficient’ daylight quantity and worth 1 point, 60% or higher is considered ‘good’ and worth 2 points, 80% or higher is considered ‘great’ daylight and worth 3 points. The grey box on the right of the plot reports whether the space passes the CHPS metric and how many points it achieves.

The plots on the lower right show the annual Daylight Saturation (DS) and annual Daylight Excess (DE) for the space. The color coding indicates the threshold of DS or DE achieved and match the color in the coverage summary bar chart above. These plots help illustrate distribution of daylight and excess throughout the space and can be seen in the screenshot image above. The View Zone Diagram button can be pressed at any time to pull up a diagram of the daylight Zones.

LEED v2.1 Single point-in-time – This is a report for the Single Point-in-time compliance path currently accepted in LEED v2.2 or older.

There are four prerequisites for this report. The prerequisties are: 1) workplane height must be within 10% of 30in (2.5ft, 0.76m) above the finished floor 2) grid spacing must be 4’ (1.22m) or less 3) the space must contain glare control strategies (it is very vague as to what this is in LEED v2.1) and 4) the Radiance parameters must be set to M,M,H or higher.

The plot on the left shows the illuminance distribution in the space for the required day and time of Equinox at 12:00PM. This compliance path requires an average of 25fc at this time. The plot on the right shows the Daylight Excess which is not a part of LEED v2.1 but good to be aware of as this metric does not have a measure to protect against excessive daylight. The box on the right gives the final status of the daylighting design relative to this metric and whether it would achieve 1 point (>75% coverage) or 2 points (>90% coverage).

LEED v2.1 Daylight Factor – This is a report for the Daylight Factor compliance paths currently accepted in LEED v2.2 or older.

There are five prerequisites for this report. The prerequisties are: 1) workplane height must be within 10% of 30in (2.5ft, 0.76m) above the finished floor 2) grid spacing must be 4’ (1.22m) or less 3) the space must contain glare control strategies (it is very vague as to what this is in LEED v2.1) 4) the space must be located in a cloudy climate (answered in a pop-up window when this report is selected) and 5) the Radiance parameters must be set to M,M,H or higher.

The plot on the left shows the illuminance distribution in the space for the required day and time of Equinox at 12:00PM. This compliance path requires an average of 25fc at this time. The plot on the right shows the Daylight Excess which is not a part of LEED v2.1 but good to be aware of as this metric does not have a measure to protect against excessive daylight. The box on the right gives the final status of the daylighting design relative to this metric and whether it would achieve 1 point (>75% coverage) or 2 points (>90% coverage).

IgCC – This is a report for the daylighting performance standard in the International Green Construction Code (IgCC). This metric report is similar to the LEED v2009 requirement in that it uses daylight illuminance under sunny equinox conditions at 9AM and 3PM to determine the daylit area. However, it requires different illuminance thresholds, a minimum of 28fc (300lux) and a maximum threshold of 418fc (4500lux). It is not a space-by-space metric but rather requires that 50% (25% for buildings > 2 stories) of a buildings net floor area be a daylit area.

There are three prerequisites for this report. The prerequisties are: 1) workplane height must be within 10% of 30in (2.5ft, 0.76m) above the finished floor 2) grid spacing must be ~3’ (1m) or less and 3) the Radiance parameters must be set to M,M,H or higher.

Next to the prerequisites is an Equinox Illuminance coverage chart that includes a Daylight Excess (DE) report simply to warn IgCC users if too much potential glare is detected as the IgCC performance metrics do not account for excessive daylight. The 28fc-418fc illuminance coverage under both a sunny Equinox at 9AM and 3PM must be greater than 50% of the buildings net floor area (greater than 25% for building > 2 stories) to comply with the code. The overall coverage that complies will be reported to the user in the Grey report box.

The plots on the lower right show the point-by-point daylight illuminace received on the workplane during the sunny Equinox at 9AM and 3PM requirement.

UDI PSBP – This is a report for the UK’s Priority Schools Building Programme that requires an 80% UDIc coverage.

There are three prerequisites for this report. The prerequisties are: 1) workplane height must be within 10% of 30in (2.5ft, 0.76m) above the finished floor 2) grid spacing must be ~2’ (.7m) or less and 3) the Radiance parameters must be set to M,M,H or higher.

Next to the prerequisites is an UDI exceeded, autonomous, and combined coverage chart. While the PSBP does not appear to have a caveat for high UDIe values, these should be kept to a minimum to minimize potential glare in the space. UDIa can help inform how well the space is saturated with daylight throughtout the year and whether on/off controls could makes sense. UDI (combined) informs the overall daylight saturation available in the space and has to achieve at least 80% coverage to the meet the metrics requirement. The space compliance with this requirement will be reported to the user in the Grey report box.

The plots on the lower right show the point-by-point UDIc and UDIe received on the workplane throughout the year.