There are two major commercial building certification programs operating in the United States right now for energy efficiency – Energy Star by the U.S. Department of Energy and LEED (Leadership in Energy and Environmental Design) by the USGBC (U.S. Green Building Council). Window film can help improve a building’s energy efficiency score in both of these programs and can even be the deciding factor that allows a building to become certified.
Energy Efficiency – Energy Star Building Certification:
Energy Star uses a 100 point scale to rate how efficient a building is compared to similar buildings around the country. The score is based on utility consumption, building type, size and location. A score of 75 is required for an energy efficiency certification, meaning the building is more efficient than 75% of similar buildings. If an upgrade such as window film is installed then at least one year of utility data is required from before and after the project to reflect the full reduction in consumption.
Energy Efficiency – Buildings Score
A building’s score can vary considerably and the effects of solar window film can be large or small. A window film that reduces electric consumption by 10% annually can add 6 points to a building’s energy efficiency score in Boston and 8 points if the building were in Los Angeles.
It’s difficult to predict what the improvement energy efficiency score will be but it can be significant enough to push a building past the 75 point minimum for certification and also open up more available points in LEED energy efficiency certification, as outlined later.
Energy Efficiency – Solar window films gain points in the following 3 categories:
1. Energy and Atmosphere – Optimize Energy Efficiency Performance (1-18 points, earn same number of points as gained in building’s Energy Star score). The energy savings potential of window film can gain points in this category. A very efficient window film project may gain 5-10 points under the Energy and Atmosphere category. It is based on the increase in the Energy Star score as explained above.
Therefore the Energy Star score must be calculated for the building beforehand. Additionally, the Energy Star score must be at least 71, otherwise the building is not eligible to gain additional points for energy efficiency in LEED.
For example, window film could raise a building’s Energy Star score from 63 to 70, but it would not increase the LEED score since the building must have at least a 71 to be eligible for LEED energy efficiency points.
An example of a better case scenario would be if window film raised the energy efficiency score from 70 to 76. The window film makes the building eligible for Energy Star certification and also adds an additional 5 points to the LEED score.
2. Indoor Environmental Quality (1 point)
• Occupant Comfort – Implement occupant comfort survey and complaint systems which cover many aspects including those affected by window film; thermal comfort, glare, and lighting levels. This point can be earned regardless of the Energy Star score.
3. Daylight and Views (1 point)
• For spaces with vertical windows: The product of the VLT and Window-to-Floor Area Ratio must be between 0.150 and 0.180
0.150 < (VLT x WFR) < 0.180
For example, if VLT = 50% and WFR = 33%: 0.50 x 0.33 = 0.165, the film would qualify.
• For spaces with only skylights and no vertical windows: must have skylight coverage (which is slightly larger than the skylight itself) for 3-6% of the space with a minimum VLT of 50%.
• This point can be earned regardless of the Energy Star score.
Energy Efficiency – Achieving Energy Star
Achieving Energy Star or LEED certification (Energy Efficiency) can be a major milestone for a building. In obtaining these certifications, a building can reduce operating costs, become more attractive to potential tenants and become a more comfortable and pleasant place to work.
It can take years to receive one of these certifications, but window film and solar power systems can offer some very significant improvements for a relatively low cost. Madico is here to help you and your customer understand how window film may fit in with their energy efficiency goals.
We can help determine Energy Star or LEED scores, estimate how much additional savings is needed to achieve a particular certification, and offer recommendations on which window films will help meet those goals. Be sure to contact Madico Technical Services for assistance on your next Energy Star or LEED project!