For long-tail solar installers, good local solar policy is crucial to business success. One trending policy initiative, solar-ready building requirements, helps eliminate barriers to local solar adoption and creates business opportunities in tough markets.

Solar-ready building requirements compel builders to make solar installation easier on new builds, whether rooftop PV will be installed now or in the future. These requirements aim to cut the costs that come with retrofitting buildings for solar and encourage building owners to consider solar as a real possibility.

NREL published a guide to help cities and states pursue solar-ready guidelines or mandates in 2012. The organization highlights six different areas that should be addressed by solar-ready legislation: determining the optimal solar system placement on a roof, accounting for building orientation and shading; minimizing obstructions in roof design; considering PV install and equipment needs such as pre-installing mounting brackets; making initial PV design considerations such as system size; researching policy factors like net metering and how they may impact a future system; and discussing zoning and permitting requirements such as solar access laws or historical preservation regulations.

The state of California and cities of Orlando, Florida, and Tucson, Arizona, along with others, have incorporated solar-ready requirements in commercial or residential building codes. Some have done so in pursuit of SolSmart designations, a program run by The Solar Foundation that distinguishes cities and counties that are “open for solar business.”

Solar-ready requirements can be a step toward a full solar mandate on new builds like California’s, which went into effect this year. New York also adopted a solar mandate for new buildings and existing buildings undergoing certain significant roof renovations in 2019.

Solar-ready requirements can also be a way for states that weren’t solar-friendly to give the technology an opening, like in St. Louis, Missouri. At the end of 2019, the city passed legislation requiring all commercial, residential and multi-family construction to be built solar-ready — with elements including a roof that can handle the added load, a reserved space on the electrical panel and, possibly most importantly, an obstruction-free space on the roof for adequate solar capacity.

St. Louis rooftops are often small to begin with, so obstructions combined with fire code setbacks have made solar installation a challenge until now, said Paul McKnight, board member of the Missouri Solar Energy Industries Association (MOSEIA) and CEO of installation company EFS Energy. He thinks the new code could help solve old problems with installations in the city.

“There’s a lot of relatively heavily shaded areas, there’s a lot of trees in the region, and then when you do have an open roof space, there’s always obstructions,” McKnight said.

Another issue he’s faced is pushback from code officials when trying to install solar on historic buildings, which are numerous in Downtown St. Louis. He hopes the new rules help make solar more accepted in these cases too.

“Having this more overarching goal and having solar-ready zones, I think there will be a lot less pushback from other authorities on where [solar] can go, so I think it’s good in that respect,” McKnight said.

EFS has not done many solar installations in the city, but McKnight is hoping this law opens more possibilities.

When solar-ready goes wrong

Missouri’s solar advocacy group MOSEIA was not directly involved in creating the solar-ready legislation, and a few exceptions to the rule are written vaguely, making it potentially easy for builders to get out of it if they really wanted to, McKnight said. He’s also concerned that code officials may not be prepared to enforce the rules due to their lack of knowledge about solar.

Even in the No. 1 solar state of California, solar-ready rules haven’t had much oversight, according to Rob Erlichman, president of installation company Sunlight Electric.

“We have seen over 17 years at least half a dozen times where we had proposed solar, the customer has said, ‘Great, I want to get my structural engineer to sign off on this,’ and the structural engineer comes back and says, ‘Yeah, no can do, the building needs to be reinforced,'” Erlichman said.

In all of those instances, Erlichman’s own engineers took a second look and determined it was in fact structurally sound enough to handle a solar load.

“I’m sure they’re all super capable licensed structural engineers, but if you’ve never done solar before and you’re not doing it five days a week, you don’t really understand how to interpret the code,” Erlichman said. “So, as a result, we’ve seen plenty of the ‘solar-ready’ situations involve over-engineering a building, which makes no sense and is a waste of money, or we’ve seen the opposite happen.”

In one example of the opposite, an international food service company told Sunlight Electric its new under-construction warehouse was being built to be solar-ready. When Erlichman looked at the building plans, he saw the steel support columns were actually too thin to support a solar load. Since he caught the error early in construction, the company had time to up-size them so solar would work.

“If we didn’t ask, then it would have been a tragedy. To reinforce those columns after the fact would probably have made it prohibitive,” Erlichman said.

In addition to load-bearing capacity, he said the ideal solar roof is made of 20-year single-ply membrane for strength and added energy efficiency. Electrical infrastructure must also be planned for to ensure a smooth solar installation later.

“If I were made national wizard for solar, in addition to ensuring that the structural integrity is adequate but not overly designed, I would want to make sure that there’s a set of standards associated with how to build the electrical infrastructure to properly prepare for solar,” Erlichman said.

Solar-ready without a mandate

Sean Price, director of commercial sales for Virginia-based installer Sigora Solar, said although there’s no requirement for constructing solar-ready buildings in the company’s home state yet, he’s seeing a trend of more building owners choosing to design net-zero buildings with solar or at least leave the option for future solar via solar-ready design.

He said the biggest solar-ready considerations for building owners is designing roofs that are structurally capable of handling the additional load of solar panels and making sure the roof has a long warranty.

“In the event that a building isn’t ready today or for whatever reason it’s just not in the cards for the near future, having that kind of proactive planning is always beneficial,” Price said.

Axium Solar of Texas has worked on some solar-ready new builds as well, most notably the Austin Central Library. The builder wasn’t sure it would install solar immediately but prepared for it anyway.

“Sometimes the solar might be an alternate, and depending on the bid and the budget that comes in, they may decide to keep it or take it out of the scope but they’re at least putting in the infrastructure just in case,” said Eric Cotney, VP of Axium.

The library ultimately decided to add solar while the building was under construction.

Cotney said there have been other new building projects where engineers have consulted with Axium to understand what size conduits to use and how to adequately prepare for solar.

Whether it’s mandate-driven or a building owner’s personal choice, preparing new construction for solar in the future is a good investment that cuts solar install costs later and increases the technology’s reach.