Solar-ready zone [For application of this section, see 84 Del. Laws, c. 143, § 2].
Del. Code tit. 16, § 7605
in effect(a) This section shall apply to new commercial buildings with a foundation footprint of 50,000 square feet or more.
(b) A “solar-ready zone” means a section or sections of the roof or building overhang designated and reserved for the future installation of solar photovoltaic or solar thermal system.
(c) (1) A solar-ready zone shall be located on the roof of buildings that are 5 stories or less in height above grade plane, and are oriented between 110 degrees and 270 degrees of true north or have low-slope roofs. Solar ready zones shall comply with Appendix CA Solar-Ready Zone—Commercial of the International Energy Conservation Code (IECC), and comply with all other requirements of the IECC or ASHRAE Standard 90.1.
(2) The following are exceptions to subsection (c)(1) of this section:
a. A building with a permanently-installed, on-site renewable energy system.
b. A building with a solar-ready zone that is shaded for more than 70% of daylight hours annually.
c. A building where the licensed design professional certifies that the incident solar radiation available to the building is not suitable for a solar-ready zone.
d. A building where the licensed design professional certifies that the solar zone area required cannot be met because of extensive rooftop equipment, skylights, vegetative roof areas, or other obstacles.
(d) Construction documents shall indicate all of the following:
(1) The solar-ready zone.
(2) Pathways for outing of conduit piping from the solar-ready zone to the electrical service panel or service hot water system.
(3) The structural design loads for roof dead load and roof live load.
(e) (1) The total solar-ready zone area shall not be less than 40% of the roof area calculated as the horizontally-projected gross roof area less the area covered by skylights, occupied roof decks, vegetative roof areas, and mandatory access or set back areas.
(2) The solar-ready zone shall be a single area or small, separated sub-zone areas.
(3) Each sub-zone shall be not less than 5 feet (1524 mm) in width in the narrowest dimension.
(f) Solar-ready zones shall be free from obstructions, including pipes, vents, ducts, HVAC equipment, skylights, and roof-mounted equipment. Solar-ready zones may be relocated to allow future installation of roof equipment as long as the 40 percent minimum allocation is maintained.
(g) A collateral dead load of not less than 5 pounds per square foot (5 psf) shall be included in the gravity and lateral design calculations for the solar-ready zone.
(h) The main electrical service panel shall have a reserved space to allow installation of a dual-pole circuit breaker for future solar electric installation and shall be labeled “For Future Solar Electric”. The reserved space shall be positioned at the end of the panel that is opposite from the panel supply conductor connections.
(i) The permanent certificate, indicating the solar-ready zone and other requirements of this section, shall be posted near the electrical distribution panel, water heater, or other conspicuous location by the builder or registered design professional.
Source: DE Code (Official Site)URL: https://delcode.delaware.gov/title16/c076/index.htmlFetched: 6/28/2026