Solar-Ready Construction
Bradley Adams (author), Darcie White, Sara Bronin, & Jonathan Rosenbloom (editors)INTRODUCTION
This ordinance requires developers to construct solar-ready homes and commercial buildings. Homeowners and commercial property owners who want to install solar energy collectors on existing structures may encounter cost prohibitive hurdles due to incompatible building and roof design, inadequate electrical components, reduced capacity resulting from shading and orientation, and high cost of retrofitting solar equipment on an existing building.[1] When drafting solar ready construction ordinances local governments should consider a variety of issues, including site orientation, roof design, shading, and mechanical specifications, such as electrical service and plumbing.[2]
Site orientation and shading analysis are critical components of “passive” solar energy collection. Passive structures are designed to maximize sunlight for heating without the use of external equipment such as photovoltaic (PV) or solar water heater (SWH) instruments. “Active” solar energy collection utilizes PV and SWH apparatuses to convert sunlight into electricity or fuel for hot water or other purposes (for a briefs on protecting solar energy systems from shading and for disputes when such shading occurs see Limiting Off Property Shading of Solar Energy Systems and Process to Resolve Tree Interference with Solar Access). PV and SWH systems benefit from south-facing site orientation and protection from shading, but in order to maximize a building’s orientation and make it more solar-ready, additional steps are necessary in the construction phase (for a description of the importance of site orientation, see Site & Solar Orientation).
To be solar-ready, rooftops should be properly angled for the specific location and/or sloped toward the south, and should be able to handle the equipment weight and weather conditions after installation.[3] All collateral materials on the roof, such as vents, chimneys, and mechanical equipment, should be grouped to reserve as much space as possible for solar collectors.[4] For larger SWH systems, consideration should be given to ensuring that the proper plumbing system is installed, connecting the rooftop to the equipment room at the time of construction.[5] Finally, solar-ready PV energy collectors require forethought on how the system will connect to the grid, the location of the electric panel on the structure, as well as the size and output of the array.[6]
This ordinance may work well with other solar-ready ordinances, such as Allow Solar Energy Systems and Wind Turbines by-Right, Change Height & Setbacks to Encourage Renewables, and Streamline Solar Permitting and Inspection Processes.
EFFECTS
Incorporating solar-ready specifications into building designs creates substantial savings for owners on installation costs and may encourage such installation.[7] Installation costs vary geographically, but research estimates that the cost of a 10 kilowatt PV energy collector can be cut by $2,644 if a structure is built to accommodate photovoltaic systems.[8] Retrofitting a building to install an SWH system impacts cost through the placement of copper pipes running from the rooftop to the equipment room, the installation of tee joints to connect the system to the plumbing, and mounting the SWH hardware to the roof.[9] As is the case with PV systems, costs vary by specific site, but research shows that for a three-panel, 96 square foot SWH system, owners can expect to save $3,057 on installation costs when designing a building to be SWH ready.[10] Savings increase as building and system sizes are scaled up. For example, up front installation costs for PV on a three-story mixed-use building can range from $5,000-$7,500, while retrofitting that same building to accommodate solar energy ranges from $20,000-$30,000.[11]
Roof design and orientation substantially impact the amount of energy that solar collectors are able to harvest. Arrays that are aligned to the east and west are 20 percent less effective than those facing south.[12] Panels atop roofs that are north-facing produce little energy, and are likely not worthwhile.[13] Rooftop orientation is a low-cost way to support solar implementation and create positive investment returns when solar energy systems are installed.[14]
EXAMPLES
Pinecrest, FL
Pinecrest requires developers of new construction or remodeling that exceeds 50 percent of the appraised building value to set forth a design indicating how the roof will be built to accommodate a PV or SWH system.[15] The ultimate owner is responsible for the eventual installation of either a PV or SWH system.[16] Pinecrest’s code requires new homes that exceed 6,000 square feet to also include several conservation-based features.[17] Requirements include the installation of either a solar or tankless water heater, a hybrid electric water heater, or a PV system.[18] The code mandates that structures have an auxiliary energy system, which can be accomplished through the installation of a solar panel and battery pack.[19] Before a certificate of occupancy is issued, the general contractor must provide an affidavit stating that the building complies with the energy code.[20]
To view the provision, see Pinecrest, FL Code of Ordinances Ch. 30 Art. 5 Div. 5.27(a)(3)(a-c).
El Paso, TX
El Paso adopted both the solar-ready provisions of Appendix U from the 2015 International Residential Code (IRC) for townhouses and detached one and two family dwellings and the Recommended Requirements to Code Officials for Solar Heating, Cooling and Hot Water Systems.[21] The IRC provision states that new townhomes and detached one or two-family homes aligned between 110 and 270 degrees of true north, which contain 600 or more square feet of roof space, comply with the solar-ready requirements.[22] The code mandates that the area of rooftops designated for solar access be free from obstructions such as chimneys and vents.[23] Construction documents must set forth the design for electrical and plumbing components to connect to PV or SWH systems,[24] and space must be set aside on the main electrical service panel to allow for the future installation of solar equipment.[25]
Pursuant to the Recommended Requirements to Code Officials for Solar Heating, Cooling and Hot Water Systems, buildings and equipment thereon must be able to support the weight of the energy collecting system and all other static (“dead load”) and fungible (“live load”) elements on the structure.[26] In addition, the equipment must be able to endure natural elements such as snow, wind, expansion and contraction due to temperature change, and seismic activity.[27]
To view the provisions, see City of El Paso, TX Code of Ordinances §§ 18.10.366, 18.32.010 (2016); 2015 Int’l Residential Code, Int’l Code Council App. U § U103.1 (2016); Recommended Requirements to Code Officials for Solar Heating, Cooling and Hot Water Systems, Council of American Building Officials 19 (1980).
ADDITIONAL EXAMPLES
South Salt Lake, UT Code of Ordinances § 15.12.840(G) (2011) (requiring new developments to be solar ready).
Long Beach, CA Municipal Code § 21.45.400(I)(3) (2019) (requiring roofs be solar ready by being able to bear an additional eight pounds of dead load per square foot. A conduit must also be provided from the electrical panel to the roof).
Louisville, CO Code of Ordinances § 15.05.020 (2018) (adopting the 2018 version of the International Residential Code’s solar ready provisions).
ADDITIONAL RESOURCES
Lisell, T. Tetreault, & A. Watson, Solar Ready Buildings Planning Guide, National Renewable Energy Laboratory (2009), https://perma.cc/6T49-SEYF (offering a comprehensive checklist for solar-ready building design).
Lunning Wende Associates, Inc., Solar Ready Building Design Guidelines, The Minneapolis Saint Paul Solar Cities Program (Sept. 2010), https://perma.cc/U24H-93QM (providing easily accessible guidelines for solar-ready buildings).
CITATIONS
[1] Andrea Watson et al., Solar Ready: An Overview of Implementation Practices, National Renewable Energy Laboratory 3-5, 9-10 (2012), https://perma.cc/68ZQ-NHYM. The National Renewable Energy Lab has created a comprehensive checklist for designing solar-ready buildings (to view the full checklist, visit the NREL website listed below in Additional Resources). L. Lisell, T. Tetreault, & A. Watson, Solar Ready Buildings Planning Guide, National Renewable Energy Laboratory 3-6 (2009), https://perma.cc/A8QW-QVKX.
[2] Id. at 4-6.
[3] Id. at 3.
[4] Id.
[5] Id at 21.
[6] Id at 24-28.
[7] Solar Ready KC Solar Installation Policy and Practice in Kansas City and Beyond, Mid-America Regional Council 21 (2013), https://perma.cc/4478-6X27.
[8] Watson et al., supra note 1, at 5.
[9] Id. at 7.
[10] Id.
[11] Best Mgmt. Practices for Solar Installation Policy, N’atl Ass’n of Reg’l Councils 3, https://perma.cc/B4HA-KBDE (last visited Jun. 17, 2019).
[12] Impact of roof orientation on solar savings, Energysage (2019), https://perma.cc/X4JZ-4Q3P.
[13] See id.
[14] See Shahrzad Fadaei et al., The Effects of Orientation and Elongation on the Price of the Homes in Central Pennsylvania, Penn. State University Dep’t of Architecture 8 (2015), https://perma.cc/3AJ4-22CZ.
[15] Pinecrest, FL, Code of Ordinances Ch. 30 Art. 5 Div. 5.27(a)(3)(a) (2018).
[16] Id. at Ch. 30 Art. 5 Div. 5.27(a)(3)(a)(1-2).
[17] Id. at Ch. 30 Art. 5 Div. 5.27(a)(3)(b)(1).
[18] Id. at Ch. 30 Art. 5 Div. 5.27(a)(3)(b)(1)(a).
[19] Id. at Ch. 30 Art. 5 Div. 5.27(a)(3)(c)(1)(c).
[20] Id. at Ch. 30 Art. 5 Div. 5.27(a)(3)(b)(1)(e).
[21] City of El Paso, TX, Code of Ordinances §§ 18.10.366, 18.32.010 (2016).
[22] 2015 Int’l Residential Code, Int’l Code Council App. U § U103.1 (2016), https://perma.cc/QKD6-JH6K.
[23] Id. at § U103.4.
[24] Id. at § U103.6.
[25] Id. at § U103.7.
[26] Recommended Requirements to Code Officials for Solar Heating, Cooling and Hot Water Systems, Council of American Building Officials 19 (1980), https://perma.cc/B599-PRFG.
[27] Id.