How to Incorporate Renewable Energy Sources into Home Building

This post has been updated.

Energy efficiency remains one of the most desired components among new and prospective home buyers. In 2020, NAHB surveyed more than 3,000 home buyers, both recent and prospective, on the types of features they prefer to have in their homes, including eco-friendly components and designs, and that still rings true today. Some of the most requested features buyers want to see in home plans are ENERGY STAR-rated windows and appliances, efficient lighting that uses less energy than traditional bulbs, and an ENERGY STAR rating for the whole house.

Benefits of Integrating Renewable Energy in Homes

Integrating renewable energy in homes can have both financial and environmental benefits. Not only do energy-efficient systems decrease the home’s carbon footprint, but materials such as solar panels pay for themselves. So even though they cost more up-front, they can save money over the life of the system.

Steps to Implement Renewable Energy in Home Construction

Any new home construction or home remodel requires a whole-house systems approach, which considers the house as an energy system with interdependent parts, each of which affects the performance of the entire system.

When planning a remodel, first conduct an energy audit to find how the home uses energy in its current state and determine how to cut energy use and cost.

Common strategies to incorporate electrification measures include:

• Sizing the electrical panels to accommodate an EV charger,
• Providing a charging outlet on the home,
• Building an all-electric home, and
• Designing homes with electrification-ready features that eventually can be fully electric.

Another important step to implementing renewable energy in home construction is green building certifications. Certifying a project to an above-code, voluntary water efficiency rating system, for example, provides independent confirmation of the water-saving practices that have been installed and validates that the home was built to a higher standard than what code requires.

The National Green Building Standard (NGBS) is an ANSI-approved residential building standard that demonstrates high-performance building in six areas: Lot Design and Development, Resource Efficiency, Water Efficiency, Energy Efficiency, Indoor Environmental Quality, and Building Operation & Maintenance. Building projects can earn one of four levels — Bronze, Silver, Gold and Emerald — after going though the process overseen by a verifier and certified by the Home Innovation Research Labs.

Solar Power: Installation and Cost Considerations

Solar photovoltaic (PV) systems use panels to convert sunlight to a home’s electrical load. These roof panels are made of individual solar cells to turn sunlight into electricity for the home.

The cost of a PV system depends primarily on square footage, weight, and number and type of panels. Monocrystalline panels are made of silicon wafers from a single crystal and are generally capable of higher efficiencies, while polycrystalline panels comprise cells that are melted together from silicone fragments and often offer a lower price point than the former.

A single-family home needs between 15 and 34 solar panels to offset most of its energy use. The amount of sunlight exposure on the roof can impact the number of panels needed. Panels cost anywhere between $2.40 and $3.60 per watt (including installation), so the more energy the PV system needs to produce, the more it will cost. On average, a 6-kilowatt PV system for a single-family home can cost around $12,700 after federal tax incentives.

Heather Laminack, a custom home builder and remodeler in Austin, says clients usually opt for solar panels once seasonal temperatures start to rise.

“Right now, in the middle of summer, it’s the peak time — people are seeing those electricity bills, and it really is a huge factor of the total cost of homeownership,” said Laminack. “A lot of times we think of homeownership cost as the cost for the home and the insurance and maybe the taxes, but it’s also the utility bills.”

A PV system can, of course, be a significant financial investment, but as the green home building industry has expanded, so has the list of financing options. Home owners can:

• Take out a loan,
• Lease the system,
• Pay through a power purchase agreement (PPA), or
• Enroll in a Property Assessed Clean Energy (PACE) program.

Utilizing Water-Conserving Technology for Residential Power

A water-driven design approach can help enable continued community development and home building throughout the country. Total hydrology planning is a methodology to identify and utilize all water resources on a project site. It uses strategies best suited to the relationship between the climate and site-specific conditions of a project to achieve a balance between a site’s water supply and demand. Such projects are better positioned to be more resilient to drought and storm events and prevent costly destruction.

Water-conserving fixtures such as toilets, showerheads and faucets are among the top green features. Incorporating these and other water-focused strategies such as ENERGY STAR appliances and structural plumbing can help save time and money on materials and labor and can help home owners save on their utility bills.

Learn more about green building at nahb.org.