Maximum cottage sets the stage for minimal environmental impact

    Placeholder while loading article actions

    Lots of individual architects and custom builders have contributed innovations to building sustainable homes by designing modular homes and residences that generate their own power, but few known as “production” builders have taken this step.

    Production builders include local, regional and national home builders who design and build multiple homes simultaneously rather than a single buyer’s personal home. But to move the needle in sustainability for the future, all types of builders will eventually need to design and build homes with environmental considerations among their top priorities.

    Cindy Wasser, Senior Program Manager for Green Building Homes Innovation Research Labs, formerly the National Association of Home Builders Research Laboratory, says in Upper Marlboro, Marlborough.

    “On the other hand, production home builders have more consistent teams than contractors who work in their homes, and can benefit from modular construction.”

    Modular home construction addresses environmental concerns, speeding up construction and may begin to have an impact on the severe home shortage in the United States. Freddie Mac estimated that nearly 4 million housing units would be needed to meet demand as of the fourth quarter of 2020.

    “Modular construction helps reduce variables in the components of a home, which in turn helps construction teams achieve their goals faster,” Wasser says. “Building parts of homes in a factory controls waste, allows for more recycling and reduces time on site for workers.”

    Climate change is spurring a movement to build storm-resistant homes

    Van Meter Homes, a regional home builder based in Northern Virginia, recently completed its second prototype “POWERhaus,” a townhouse constructed in Chantilly, Virginia, which the company is using as a prototype for its future townhouse development. Its first prototype was a single-family home.

    “We’ve had a factory in Winchester, Virginia, since 2008 where we build roof trusses and wall trusses, so we wanted to do more in the factory environment to achieve greater efficiency,” he says. Mike Sandkohler, vice president of construction operations at Van Meter Homes, based in Ashburn, Virginia. “Also, most people in the construction industry understand that the skilled labor shortage that we are all experiencing is not going away. Modular construction can help us manage this shortage.”

    Sandkuhler says Van Meter intends to incorporate more homes into its product mix in the future, which is why the company chose to design a modular townhouse for its second project.

    Van Meter Homes . brought Joseph Wheeler, Professor of Architecture and Co-Director of the Center for Design Research at Virginia Tech School of Architecture and Design in Blacksburg, Virginia, serves as a consultant while sabbatical to help redesign a townhouse model as a prefabricated home concept.

    “The focus was on developing cartridges that could be manufactured in their factories to increase efficiency,” Wheeler says. “Residential homes require a firewall between each unit, so we needed to do research and development to be able to carry out this work within a modular factory setup.”

    The construction period is two months

    A big advantage of this modular construction is that the cottage is built in two months when most new construction takes longer.

    “The beauty of the modular construction is that the site and foundation can be worked on simultaneously with factory-made cartridges,” Sandkuhler says. “It cuts the construction time from four or five months to two months.”

    Van Meter and Wheeler are taking the lessons they learned while building this cottage for their next project, a row of four homes in Ashburn. Sandkuhler expects those homes to be on site sometime this summer.

    What would climate change mean for your home

    “The plant is less than 45 miles from where we’re building, so we’re minimizing the amount of fossil fuels and the time needed to get the cartridges to the construction site,” Sandkuhler says.

    Transportation and housing account for more than half of all greenhouse gas emissions in the United States, according to a PBS News report in 2019, with 33.6 percent of those emissions coming from housing. Utility use accounts for 25 percent of housing emissions.

    Wheeler says reducing the distance from the factory to the home site also addresses the truck driver shortage.

    “We also learned that it’s better to make smaller modular pieces rather than bulky panels because that way you don’t need bulky cranes and bulky trucks that can be difficult to maneuver in neighborhoods,” Wheeler says. “The smaller components are also more flexible in terms of design, so you’re not stuck in the big box mentality of prefab modular homes.”

    Future Chantilly Townhouse

    The first model POWERhaus home, for sale for $89,990, includes 2,706 square feet of living space with three bedrooms, three bathrooms, and a two-car garage. The model includes a variety of special features as it serves as a research project for Van Meter.

    In addition to solar panels, home energy storage Tesla batteries, and an electric car charging station, the home has high-tech features like a self-cleaning bathroom, a whole-home safety monitoring system, smart mirrors, smart lights and touchless faucets.

    The “strength” part of the name represents the goals of the townhouse, including:

    • Progressive innovative building technologies.
    • Optimized to deliver peak performance for all systems in the home.
    • Waste conscious to build processes that reduce waste.
    • Efficient, to increase energy efficiency and convenience.
    • Renewables to increase sustainability by using clean energy sources.

    “For this home, we choose one of our most popular floor plans to convert to a modular design,” says Sandkuhler. “If you enter this house, it will not feel like a modular house.”

    Van Meter has used an improvement program in the factory that keeps track of every piece of material used and where and when it will be needed, Wheeler says, which could lower costs for modular-built homes in the future.

    “For the next set of townhouses, we can make a wagon with all the pieces in it like a Lego set of nested products,” Wheeler says. “There is less waste and lower costs when we can build more efficiently and with greater accuracy.”

    Your spring home maintenance should include an energy audit

    Wheeler says they quickly learned that the roof of the two upper floors is best left when cartridges are shipped to make it easier to install everything on site.

    “In the future, modular, compact homes will provide homeowners and builders the ability to expand over time,” Wheeler says. “If you design a community to be modular from the start, you can develop lots and spaces between homes to accommodate the addition of future units. So, start with an affordable two-bedroom, one-bathroom home and scale it up to a four-bedroom, four-bathroom home.”

    Energy efficient homes

    While the next set of Van Meter modular homes will be energy efficient, Chantilly POWERhaus achieves net positive benchmarks, meaning the home produces more energy than it uses. The combination of solar panels, tight construction, and additional insulation, along with a Tesla Powerwall for solar energy storage, means there should be enough extra power to charge an electric car as well as power the home.

    “Commitment to designing and building net positive homes is the direction the market is going, but cutting-edge innovations are usually found in the luxury bespoke home market,” Wasser says. “Builders and consumers are really waking up to the need for more sustainable energy, lower energy bills and homes being able to withstand power outages.”

    The Home Energy Rating System (HERS), developed by the Residential Energy Services Network (RESNET), a nonprofit organization founded in 1995, measures the energy efficiency of homes. The lower the HERS number, the more energy efficient the home is. A HERS score of 100 means the home was built to 2006 Energy Efficiency Standards. A typical resale home has a HERS score of 130. A HERS score of zero means that the home generates the same amount of energy it uses. A net positive house has a negative HERS score.

    How did the metropolitan area housing market perform in 2021 by zip code

    “This is an all-electric home that achieves higher levels of energy efficiency not only because of the way it is built but also because of the systems we have installed,” Sandkuhler says. “It has induction cooking and a ductless multi-zone heating and air conditioning system, which is very efficient.”

    Wheeler says the Mitsubishi Multi-Zone Mini-Split System is compact and allows you to heat or cool one level of the house at a time rather than the entire house. The cottage also has motion sensors to control the lights and an entire home energy monitoring system with leak detectors that automatically shut off the water if a leak occurs, all of which add to the home’s sustainability.

    “You get a slight energy efficiency benefit in a detached home compared to a single-family home, especially indoor units, because of the insulation benefits of glued-together homes,” Wasser says.

    Not the cheapest cheap housing

    Sandkuhler says building cartridges for a home in a factory that provides a controlled environment eliminates delays due to weather, but the process doesn’t save money yet.

    “We’re saving time in this area, but the costs haven’t come down yet,” Sandkuhler says. “Our first goal with this project was research and development, and our second goal was to increase efficiencies to make this as similar as possible to homes built on the site.”

    Building four kitchens at once is efficient, but Sandkuhler says the level of attention to every detail is the same as in on-site construction.

    “A different level of accuracy is required when the cartridges are stacked on top of each other,” he says. “You need to coordinate every detail. For example, we want all our homes to be solar ready in the future, but that means we need to make changes to the roof trusses so that it can handle the extra weight.”

    Increasing the affordability of homes built with modular construction is another challenge.

    “The goal is not to build the cheapest housing,” Wheeler says. “The goal is to deliver a higher quality product more efficiently. Eliminating waste and exposure to weather can reduce costs as well as adapt to the use of labor in the factory.”

    Ultimately, Wheeler believes, more skilled contractors will do some of their work at the plant.

    “If all the components of each home were uniform and precise, the on-site portion of construction could be done more easily, and you wouldn’t need a supervisor to oversee everything,” Wheeler says.

    Wasser says one of the misconceptions many consumers have is that a modular home will be more difficult to renovate or rebuild in the future.

    “In fact, there are significant consumer benefits from factory-built components,” Wasser says. “It is a more controlled environment for construction that allows for higher quality components and more consistency. It will not affect renovations at all. Homeowners will be able to do anything they want with the house as if it was built on site.”

    Builders can also “protect the future” of a modular home if they choose, such as by installing wiring for a battery panel to store solar energy.

    “Consumers can come into the showroom and make their decisions just as they would with other types of new construction,” Wheeler says. “The big difference is that they can move home in a couple of months instead of two or three times more.”

    For Wheeler and Sandkuhler, investing time and money in research to build a POWERhaus is about using technology to build a better home that provides the same experience to homeowners as any solidly built home built with traditional methods.