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Designing buildings with daylighting controls is a complicated process, requiring analysis and communication across multiple disciplines. Because of this, daylighting often appears inaccessible to building owners and first time designers. Following is a set of general architectural, lighting and interior design guidelines. These guidelines may be used as a starting point for daylighting design and could be included in design documents.
Please note though, that these are general guidelines that should be customized through more extensive analysis for specific climates and building types. Consult an experienced designer before using these guidelines on an actual project. Email Scott Schuetter, PE, LEED AP BD+C for more information.
You may also find our tip sheet helpful: Calibration and commissioning for energy savings from daylighting (pdf)
Choose a project type:
Warehouse
Provide skylights or tubular daylighting devices with automatic daylight harvesting controls in areas with frequent occupancy. The daylit zone shall be defined as the space that is equal to the height to the bottom of trusses extended equally in each direction below the skylight as shown in the following figure.
Architectural
| SKYLIGHTS | TDDs | |
| Max. Skylight/TDD to Roof Ratio | 3% | 3% |
| Min. Visible Transmissivity | >70% | >50% |
| Min. Solar Heat Gain Coefficient | 0.40 | 0.30 |
| Max. Assembly U-Value | 0.60 | 0.50 |
Lighting
- Maximum lighting power density of 0.6 W/ft2 through use of fluorescent T8 or HID light fixtures.
- Install photosensors and controls connected to the lighting system serving the daylit zone to turn off or dim the lights when the footcandle level is equal to or greater than 30 footcandles. Provide lower footcandle targets for areas with 'bulk' items, than for areas with 'fine' items.
- In areas of infrequent occupancy, photosensor controls are less effective. Instead, install occupancy sensors and controls connected to the lighting system to reduce electric lighting levels during unoccupied periods.
- Allow daylight controls to reduce electric lighting to 0 - 10% illumination through a stepped dimming control system with a minimum of 2 steps and off.
- Utilize independent, third party commissioning of the daylighting control system. Ensure that the daylighting control system is installed correctly and is operational.
- Conduct introductory training for building facility staff.
Interior Design
- Use light, reflective colors and finishes in daylit areas.
- Ceiling Reflectance = 80%
- Wall & Rack Reflectance = 60%
- Floor Reflectance = 30%
- Position storage racks in between skylights and not directly under them.
Office
Provide windows and curtain walls with automatic daylight harvesting controls in daylit areas. The daylit zone shall be defined as the space that is equal to 1.5× the height of the window extended perpendicularly into the space as shown in the following figure.
Architectural
| WINDOWS | |
| Max. Window to wall Ratio | 30% |
| Min. Visible Transmissivity | >50% |
| Min. Solar Heat Gain Coefficient | 0.35 |
| Max. Assembly U-Value | 0.35 |
Utilize external shades on the south-facing façade and vertical fins on the east and west-facing facades to block direct sunlight from entering the space.
Lighting
- Maximum lighting power density of 0.9 W/ft2 through use of direct/indirect T5 or high performance T8 fluorescent light fixtures and LED recessed downlight fixtures.
- Use task lighting in all offices and where needed for occupant reading.
- Install photosensors and controls connected to the lighting system serving the daylit zone to turn off or dim the lights when the footcandle level is equal to or greater than 40 footcandles.
- Position directional photosensors such that they view parallel to the windows and are shielded from direct view of adjacent windows.
- Install continuous dimming daylight controls to reduce electric lighting to 0 - 10% illumination. If continuous dimming controls are cost prohibitive, install stepped dimming controls with a minimum of 3 steps.
- Utilize independent, third party commissioning of the daylighting control system. Ensure that the daylighting control system is installed correctly and is operational.
- Conduct introductory training for building facility staff.
Interior Design
- Use light, reflective colors and finishes in daylit areas.
- Ceiling Reflectance = 80%
- Wall & Partition Reflectance = 60%
- Floor Reflectance = 30%
- Select cubicles with low partition heights (3.5'-4.0') parallel to the daylighting windows.
Classroom
Provide windows and curtain walls with automatic daylight harvesting controls in daylit areas. The daylit zone shall be defined as the space that is equal to 1.5× the height of the window extended perpendicularly into the space per the following figure.
Architectural
| WINDOWS | |
| Max. Window to wall Ratio | 30% |
| Min. Visible Transmissivity | >50% |
| Min. Solar Heat Gain Coefficient | 0.35 |
| Max. Assembly U-Value | 0.35 |
Utilize external shades on the south-facing façade and vertical fins on the east and west-facing facades to block direct sunlight from entering the space.
Lighting
- Maximum lighting power density of 1.0 W/ft2 through use of direct/indirect T5 or high performance T8 fluorescent light fixtures and LED recessed downlight fixtures.
- Provide multiple lighting zones and/or shade control to allow varied lighting scenes for A/V presentations, note taking, and test taking. Ensure that the primary teaching surface and A/V surface can be shielded from direct sun at all times.
- Install photosensors and controls connected to the lighting system serving the daylit zone to turn off or dim the lights when the footcandle level is equal to or greater than 75 footcandles.
- Position directional photosensors such that they view parallel to the windows and are shielded from direct view of adjacent windows.
- Allow daylight controls to reduce electric lighting to 0 - 10% illumination.
- Utilize independent, third party commissioning of the daylighting control system. Ensure that the daylighting control system is installed correctly and is operational.
- Conduct introductory training for building facility staff.
Interior Design
Use light, reflective colors and finishes in daylit areas:
- Ceiling Reflectance = 80%
- Wall Reflectance = 60%
- Floor Reflectance = 30%
