The 2018 Seattle Energy Code (SEC) specifies current energy efficiency requirements for new commercial construction and renovation projects within the city. Various sections of the code contain specific on-site renewable energy requirements that can be easily met with a rooftop solar PV system.
C406.5 Energy Efficiency Credit – New commercial buildings, additions, and changes of space conditioning or occupancy have the opportunity to utilize an on-site solar PV system to fulfill up to 3 of the 8 total energy efficiency credits required per project. To utilize this option, projects must install at least 0.25W/ft2 of solar panels. For example, a building of 10,000 ft2 of conditioned space would require 2.5 kW of solar to fulfill this option, or about seven modern, high-efficiency solar panels.
C412 Solar PV Requirement – Each new building or addition larger than 5,000 ft2 must include a solar PV system of at least 0.25W/ft2 of conditioned space. Thus, for a project obligated to fulfill the requirement of C412 and seeking to maximize required energy efficiency credits through a more robust solar PV system, a total of 0.5W of generating capacity per ft2 of conditioned space would be required, or about 15 solar panels for a building with 10,000 ft2 of conditioned floor area.
C411 Solar Ready Zone – In addition to the requirements related to solar PV installations for commercial structures, section C411 requires the provision of a ‘solar zone’ on the roofs of commercial buildings of 20 stories or less, of up to 40 percent of the roof area. Note that while solar PV systems installed to meet compliance with C406.5 and C412 can be located within the prescribed zone, the total area of the identified solar zone may extend beyond the initially installed PV system’s area requirements, and possibly require additional building preparations.
Seattle Energy Code complies with the Washington State Energy Code (WSEC).
Note: This summary of the 2018 Seattle Energy Code renewable energy requirements should not be used as a substitute for codes and regulations.
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