With codes and market forces continuing to raise the bar for home performance, forward-thinking builders and developers are looking beyond the individual home. Some see the next big thing in sustainable building as the "smart neighborhood."
The smart neighborhoods I've looked at all include community-scale energy generation and energy management, while some go further by prioritizing clean air and clean water. The trend is relatively new, however, and developers are still figuring out what works in a business sense. Challenges include how to keep costs down, how to work with the electric utility, and how to determine what features buyers will value.
It Starts with the Home
The core of the smart neighborhood is the smart home. It combines healthy, energy-efficient construction with electronic features like rooftop solar panels, backup batteries, connected appliances and home automation.
Most people think of home automation as a control system for lights, shades, music, security, and HVAC. While the automation I'm talking about here will ideally offer those functions, its main purpose is to support sustainability goals. For instance, during peak hours when electric rates spike, the automation system could switch the home to battery power, while also reducing draw by cycling or powering down connected appliances.
When it comes to solar, the ability for individual homes to generate and manage their own power is a big step towards making a community sustainable. What makes the smart neighborhood different is that it aggregates that ability in a "solar garden" or "microgrid"— a centrally located solar array that replaces or supplements the panels on individual homes.
Centralization requires utility cooperation, but utilities tend to be cautious. For instance, they need the ability to isolate the microgrid when necessary to protect line workers. They will also be more apt to warm up to a smart neighborhood project if it gives them some control over individual homes' daily power usage as a demand management tool. Homeowners will likely only agree to that type of control if they save money on their electric bills.
As examples, I want to look at two communities that have been designed to test this concept: the recently-completed 62-home Reynolds Landing in Birmingham, Alabama and the 12-home Heron's Nest in Shallotte, North Carolina, which is currently under construction.
Reynolds Landing was a utility-driven project and has been the subject of national attention. Alabama Power partnered with Signature Homes, the U.S. Department of Energy’s Oak Ridge National Laboratory, the Electric Power Research Institute, and technology vendors like Carrier, Rheem and Vivint.
The community's homes do not have rooftop solar panels. Instead, the utility consolidated the panels—along with battery storage and a backup gas generator—into a 2 1/2 acre microgrid site. Homeowners agree to let the utility remotely adjust their electric loads via smart thermostats and other controls.
The community was meant to be a test case. "We wanted to get a better understanding of technical challenges," says Jim Leverette, a Research Engineer with Southern Company, Alabama Power's parent. Now that they have that understanding, they are looking to expand the program. AlabamaNewsCenter.com reported in October that Alabama Power was partnering with at least three other builders to create similar neighborhoods.
Heron's Nest was also conceived as a pilot, with close cooperation between the developer and Brunswick Electric. Each home will have 3 kW of solar and the community itself will have a 63 kW microgrid. Besides providing free power, the combined solar capacity will be enough to power the homes if there's a power outage.
Each home will also include rooftop solar panels and micro-inverters, grid interactive water heaters from Carina Technology, and Ecobee smart thermostats. During weather events and peak times, the utility can control the water heaters and thermostats to better manage the grid. However, residents have the choice of whether or not to opt in.
But the Heron's Nest team also knew that while energy independence is important, it's icing on the cake. What really attracts buyers is a connection to nature.
Graham Adams, the project's builder and developer, was a landscape architect for 40 years and incorporated lessons learned over that career on how to create a sense of place. He made it a priority to preserve more natural features than in most developments, including many of the site's mature Live Oak trees. That included preserving a natural lagoon on the property and adding an artificial one.
"We kept the lots small, so though we have a total of 10 acres we only built on five of them," he says. That left habitat for turtles, herons and other animals that live in the area. The ample vegetation also helps cleanse the air by absorbing pollutants.
To keep drainage out of the lagoons, the site was engineered to be self-filtering. Each home includes a driveway bio grid (a product called True Grid) which keeps pollutants out of groundwater by filtering them on the spot. Installed cost is on par with a concrete driveway.
Adams also applied the self-filtering strategy to the community's roads. Although the roads are paved with standard asphalt, there are no storm drains or retention ponds. Instead, small weep pipes installed under sidewalks direct runoff to low-lying areas of grass or gravel, where water can naturally seep into the ground.
Clean drinking water was also important. Each home has a reverse osmosis and filtration system from Kinetico Water Systems that removes up to 99% of contaminants. "This will ensure safe, great tasting water for our residents, and will reduce plastic waste by reducing the need for bottled water," says Adams.
There were of course challenges. One was affordability. Adams wanted to keep prices in the $180,000 to $240,000 range, which is reasonable for a house on the coast, and so decided to make the homes relatively small—900 to 1700 square feet—with simple, easy-to-build designs. To compensate, he specified high-end finishes like stone countertops. "The feel is that of a 1/2 million dollar cottage," he says. And because storage is always a challenge in small homes, he used box or "attic room" trusses to create 500 sq.ft. of usable conditioned space overhead.
Another way he kept costs down was to make some technologies optional. For instance, each home has Category 6 data wiring for a home automation hub as well as electrical wiring for a vehicle charger. If homeowners want the hub or charger, however, they will have to pay for them.
More to Come
Adams intends for Heron's Nest to be the first of several such communities in the state. The utilities seem to be on board with this goal. "As North Carolina continues to grow and cooperatives continue to pursue innovative energy solutions, I believe we will continue to see more projects like Heron’s Nest,” says Jim Musilek, Director of Innovation and Business Development at North Carolina’s Electric Cooperatives.
But the growth of smart neighborhoods will require firm leadership from builders and developers. For instance, Adams pitched the concept to a couple of builders, but they insisted on making solar an option. He considers solar one of the features a smart neighborhood must have so, rather than compromising, he moved on.
Adams is convinced that kind of commitment will pay off in the long run. "There's a growing market for clean energy and for communities with healthy environments," he says. "At some point I expect these features will be expected, and we want to get ahead of that."
Alex Glenn is a building scientist and energy consultant in the clean energy industry. He provides energy management, residential construction, and smart grid modernization solutions. His expertise includes building science, energy efficiency, home performance, and sustainable construction.