Natural daylighting is an important aspect of today’s green building standards. Both LEED and Living Building Challenge (LBC) have specific requirementsfor how much daylighting needs to be incorporated into a building. With the Brock Environmental Center targeting LEED Platinum and LBC certifications, daylighting was an important feature during the design, planning and preconstruction phases of the project.
Having access to daylight inside buildings leads to better productivity and makes for a healthier and more comfortable environment for occupants. In addition, daylighting reduces energy use for lighting and cooling. However, while it is important to have open spaces and low partitions between offices for light transfer, a facility should not be designed at the expense of increased glare, too much heat gain or loss of privacy.
LEED and LBC Specifications
Both LEED and LBC specify daylighting in their requirements. According to LEED, in order to award the IEQ 8.1 credit, a building has to “achieve a minimum daylight factor of 2% (excluding all direct sunlight penetration) in 75% of all spaces occupied for critical visual tasks.”
LBC incorporates daylighting into the criteria for the Energy Petal in order for a building to have net-zero energy. It is also mentioned in the Health Petal—which specifies “every occupiable interior space of the project must have operable windows that provide access to fresh air and daylight.”
Daylighting in the Brock Environmental Center
There are several programmatic natural daylighting design features that were incorporated into the Brock Center design that will allow it to achieve LEED Platinum and LBC certification:
A daylighting study during the planning process identified how the building needed to be positioned on site in order to take advantage of southern sun exposure. The positioning of the building invites a healthy amount of sunlight yet minimizes the amount of solar heat gain into the interior spaces.
Triple glazed windows
Most buildings today have “dropped ceilings” that prevent natural light from reaching the interior of a building. The Brock Environmental Center will incorporate an upper clerestory triple glazed window system, or windows above eye level, to absorb midday sunlight and distribute it inside the building. It will also provide the appropriate amount of sunlight in the morning and afternoon when the sun is low on the horizon and hits the building directly.
Interior light transfer
The majority of the facility’s interior spaces were designed to allow for transfer of sunlight from one space to another. This will be accomplished by not using full height walls and incorporating furniture that will provide a good balance of sunlight transfer while still maintaining privacy.
Accommodating heat gain
The building’s mechanical system and exterior envelope were designed to accommodate the heat gain from the daylighting intended to infiltrate the building interior. The natural ventilation (being discussed in more detail in a future blog post) will also provide additional air circulation to the interior spaces to balance the heat gain from the natural daylighting.
The Brock Environmental Center project team has worked hard to carefully plan these green initiatives in order to make it a net-zero energy facility. These daylighting tactics will not only conserve energy, but also make the interior space more inviting and productive for the occupants.
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