Building a home? This contractor explains how to make it solar-ready

As Richard Zagame builds his newest home, he's thinking about more than just today's needs. The veteran contractor knows that with electricity prices soaring and solar technology improving, future homeowners will likely want clean energy options. That's why his current project in Newton, Massachusetts, is designed to make adding solar panels as simple as plugging in an appliance.

"It's less invasive and cheaper to have the wiring built in beforehand instead of setting it up when the home's all finished," said Zagame, who owns Metro Construction and has over 30 years of construction experience in New England.

"It's wise to make the home as energy-efficient as you can, especially today when electricity prices are as expensive as they are—people are going to want solar,” he said

Zagame's approach reflects a growing trend across Massachusetts and beyond, as many municipalities have adopted “solar-ready” requirements for new builds. Building a solar-ready home means designing the structure for easy compatibility with solar energy systems, with optimal roof orientation and pre-installed electrical infrastructure that can save future homeowners thousands of dollars and reduce installation time.

A study by the National Renewable Energy Laboratory (NREL) backs up Zagame’s point—installing solar at the same time as home construction can significantly cut costs overall. Whether you're a builder working on designing a home that's ready for solar, or a property owner in the midst of construction, there are solar-ready design guidelines that can make the process easier for everyone.

The solar planning process begins early in design. Zagame said his architect conducted an irradiance study on the house to determine where rooftop solar panels would generate the most electricity. This analysis allows electricians to map out the best wiring routes from the first-floor electrical panel to the third floor, ready for future rooftop connections.

"It's not difficult at all for the electrician—quite the opposite. It's very easy when the house is in the rough because it's all open," Zagame explained. "Being solar-ready is part of the requirement for the city of Newton, so it has to be inspected while the walls are still open. This house has been inspected and we’re all up to code," he noted.

When designing a home that is solar-ready, it’s important to pay attention to:

• Steepness and orientation of your roof:. A south-facing roof that is angled between 30 and 45 degrees is the most ideal for solar.

• The layout of roof vents, chimneys, dormers:. Will any of these things cause shading on your solar panels during the day? Shade can negatively impact electricity production.

• Roof load-bearing specifications: Make sure that your roof can bear the additional weight of a solar panel system.

• Designated roof mounting points for your solar panels: Integrating the mounting points can save time and money, and reduce the likelihood of damage to the roof during solar installation.

There are also key electrical considerations to take into account, including:

• Installation of electrical conduit from your main electrical panel location to the roof:You'll need to run a conduit between your solar panels and your electrical panel.

• Specification of main service panel and circuit breakers:. Ensure that your setup can handle a solar panel array.

• Space near the main electrical panel for PV inverters and other equipment: While most of your solar panel system is on the roof, some components need to be installed near your electrical panel.

You can learn more from the U.S. Department of Energy's Solar Energy Guide for Homebuilders.

While those tips are ideal for optimal solar conditions, builders like Zagame must also meet specific solar-ready requirements to comply with local building codes. 

Massachusetts has become a leader through its stretch energy code, an optional but increasingly popular building standard that cities and towns may adopt to exceed baseline energy efficiency requirements. As of 2025, 45 municipalities—including Newton, Watertown, Somerville, and Cambridge—require new homes to include designated roof space and electrical infrastructure to support future solar installations.

According to Massachusetts’ state code, solar-ready requirements apply to: 

• New single-family and two-family homes with roof areas between 600 and 2,000 square feet generally face south (oriented between 110° and 270° of true north).

• Townhouses and similar attached dwellings that meet the same criteria.

• Large commercial buildings over 100,000 square feet.

These new building requirements ensure that homes are ready for solar panels even if a future homeowner doesn’t install them. Homes are only exempt from solar-ready requirements if they’re too heavily shaded (more than 70% of daylight hours annually) or lack suitable roof orientations.

Zagame said you can think of solar-ready infrastructure similarly to pre-wiring a home for cable TV or internet—standard features we’ve come to expect in modern homes. To meet Massachusetts’ solar-ready standards, homes must include the following elements, according to the stretch energy code:

• Reserved roofspace: At least 300 square feet of unobstructed roof area designed for future solar panels

• Electrical infrastructure: An electrical panel with a reserved space for the circuit breaker needed to connect solar panels. (This eliminates the need for costly electrical panel upgrades later.)

• Documented pathways: Construction documents must show how the electrical conduit will run from the designated solar area to the electrical panel, streamlining future installations. 

• Structural readiness: Roof load calculations confirm the structure can support the additional weight of solar panels and mounting equipment.

Zagame admits the rules are much stricter than they used to be, but he says he believes the new standards are a smart policy for the future of home construction.

“I like the fact that the state of Massachusetts is more up-and-up on building more energy-efficient homes compared to a lot of the rest of the country,” he said. “In Newton, it doesn’t get much stricter—you can’t put in gas anymore, they don’t want any fossil fuels, period. Which, really, is a good thing.

“The technology we have today, like the new heat pumps and induction stoves, has come a long way. And then if you have solar, it makes even more sense.”

Even where solar-ready isn’t required by municipal code, building these features offers big advantages that smart builders and buyers can recognize:

• Increased home value: Solar-ready infrastructure can be an attractive selling point, especially in homes with all-electric appliances.

• Solar installation savings: Having the electrical infrastructure ready can shave thousands of dollars off your solar installation since electricians won’t need to upgrade panels or navigate complex routing through finished walls.

• Faster installation: With the groundwork laid, solar installations can be completed more quickly. “It basically removes a step for the solar installer,” Zagame said.

• Future flexibility: Even if solar isn’t in the immediate future for the new homeowner, they’ll have the option to easily add it down the line.

• Quality assurance: Having the electrical work inspected and approved during the construction process ensures all the infrastructure meets code and functions properly. Not only is this peace-of-mind for safety, but it can also speed up the solar installation timeline.

Plus, Zagame said adhering to solar-ready requirements doesn’t add much extra time or money to the construction process, making it a no-brainer.

Massachusetts' solar-ready requirements reflect a broader national trend toward "solar-friendly" building practices. California has implemented similar requirements, and other states are also considering comparable measures as solar technology becomes increasingly mainstream and affordable.

The approach makes particular sense as cities and towns work to meet climate goals and residents face rising electricity costs. Communities adopting these standards are essentially future-proofing their housing, ensuring that clean energy remains accessible as technology evolves.

"I'm all for more energy efficiency," Zagame said. "Our electric bills are through the roof, so we should all start putting solar panels on them.”