Once in awhile, a client provides so much inspiration that contractors and architects can't help but become better at their professions. Claudette Stern of Ann Arbor, Mich., was this client to Doug Selby, chief executive officer of Meadowlark Builders, and Michael Klement, principal of Architectural Resource LLC, both of Ann Arbor.
Stern, a found-object artist, wanted her profession to inform the design of her remodel, demonstrating that everything has a purpose and there is no "away" to which things can be thrown. She also kept future generations in mind, not only by choosing to remodel in a way that has less impact on the environment, but also by thinking about how future homeowners might use her space. Because of Stern's ideology, the whole-house remodel continuously spiraled into something new and was coined the Nautilus House. The thoughtful process with which the project was completed led to a LEED for Homes Platinum certification and the Silver award in Qualified Remodeler's 2010 Master Design Awards program.
Like many remodels, Stern's project began as a solution to a problem; her split-level home that was built around 1940 had a leaky roof. Because Stern long had been interested in high-performance-building techniques she wanted to know how to replace her roof in an energy-efficient manner while considering how to optimize the space underneath the roof for future homeowners. She opted to expand what was once her attic into an artist workspace, giving future owners the option of creating second-floor bedrooms. Serendipitously, the 2- by 10-inch attic floor joists were spaced 16 inches on center. "That attic was strong enough to be a new platform for a second floor without changing anything," Klement remembers. "It was almost as though the house was waiting to have a second floor built on top of it."
Klement and Selby, who have partnered on several green-building projects, worked as a team while creating the Nautilus House. The design concept incorporated a curvilinear roof form that would enclose the new second-floor space and allow the team to use six 12-inch-thick, 8- by 24-foot (the largest size available) structural insulated panels, or SIPs, as a roof deck, eliminating additional framing and thermal bridging. Waste also was eliminated because each SIP only required a slight bevel cut for mating purposes. Lastly, the curved roof would allow solar panels to be staggered and offset up the slope to ensure no panel would cast a shadow on another.
Stern's interest in adding solar panels to the home was refreshing to Klement. He explains: "When faced with the choice of a $30,000 kitchen remodel or a 4-kilowatt rooftop array of solar panels that will provide most of her power in the summer and much of it in winter, Claudette chose the solar panels. We're seeing a paradigm shift in our industry about what is perceived as valuable and beautiful."
It is obvious that adding solar panels to a structure that isn't energy efficient is a waste, so Selby and Klement got to work improving the existing home's envelope. "We retrofitted all the insulation in the house and wanted to cut the air and water infiltration significantly," Selby says. "We wrapped the whole house in a commercial-grade air/water barrier and then we created a rain screen by fastening 2- by 2-inch cedar furring strips 24 inches on center into the house's framing. That created a 1½-inch gap between the siding and sheathing of the house, so any moisture that gets behind the siding is going to run down the air/water barrier, allowing the area to dry out so the siding on the backside won't absorb any water. We attached the siding to the furring strips."
Klement notes that a rain-screen application also allows easy modification of the home's cladding. "These thicker furring strips allow cladding systems to be attached without penetrating the air/water barrier. In the future, if the owner wants to change the cladding, it can be installed to the furring strips."
Selby adds: "Claudette wanted her house to be a living palette. She thought there may be cladding options in the future that do more than just clad a home and wanted to retain the ability to easily change this component."
In addition to improving the building envelope, Stern wanted an energy-efficient heating and cooling system. Her existing HVAC system was at the end of its life well before renovations began and she was interested in geothermal as the replacement. Meadowlark Builders designed a geothermal system for the Nautilus House but actually installed it in her home about a year before renovations.
As a found-object artist, Stern was adamant about finding a place for everything that was removed from her existing home. "We reused just about everything and ended up with about 10 yards of total waste," Selby comments. "It was a good learning experience. It sounds onerous, but it wasn't that bad, which inspired us to do this on all our projects."
For example, the team opted to remove Stern's existing fireplace. The utility-grade brick became the floor of the home's biosolarium, which is an open area that creates an opportunity for passive heating and cooling. "One of the things we like to do in green building is tap into as much free energy as we can find," Klement explains. "We analyzed the natural aspects of the site, and the tree corridor allows the prevailing winds that come from the southwest to funnel toward the house. That affects positive pressure on the house's southwest corner. On the northeast corner, we then have negative pressure."
The team created an overlook between the second-floor plane and the biosolarium, allowing warm air that rises to stratify at the top of the home's arch. On the leeward side of the house—the negative-pressure area—motorized windows open and draw the warm air out of the home in summer. "We're using convective action, position and design of the house, and location of windows to work as an integrated system to passively cool the house," Klement remarks.
During winter, warm air that has risen is pulled into what the team calls the monolith, a tower that separates the biosolarium and dining room. The top of the monolith has three 10-inch ducts that are tied to the mechanical system.
"Warm air is drawn in and routed down to the biosolarium floor," Klement says. "We dug out the floor 24 inches and lined the excavated area, like a bathtub, with rigid insulation on all sides. The monolith ducts are branched into smaller ducts, forming an exchange manifold running through what we filled back in with sand and limestone.
We placed the biosolarium's brick floor on top of that. This warm air then tempers what would be a cold floor in the winter."
Stern's profession also inspired creativity with materials. The home's east side features windows of different shapes, sizes, styles and types of glass. Meadowlark Builders contacted its local window manufacturer representative and was able to intercept one of the manufacturer's trucks taking a load of new windows that couldn't be used back to the plant for recycling. "One of the core tenets of green building is to reduce the amount of materials going to the waste stream," Klement remarks. "We actually went to the waste stream and extracted material for this project at a deep discount. This is a perfect example of knitting together opportunity with the client's goals, green-building strategy and energy goals."
Yet another example of finding new uses for materials is the OSB that features a water-based floor finish and is installed as flooring in the second-floor artist space. "It looks great at 32 cents per square foot and required very little labor," Selby notes.
Although Selby and Klement have worked on green-building projects before, the Nautilus House was a valuable learning experience for both of them, and they hope the house will inspire others to build and remodel in an energy-efficient manner. "The most incredible opportunities for change occur when we have the greatest challenges," Klement remarks. "We are dealing with the climate crisis, the energy crisis and the economic crisis. Yes, green building is different, but I cannot think of a more exciting time to be in the remodeling industry than right now. Not only is it exciting to do beautiful work but Harvard University's Joint Center for Housing Studies says there are 130 million existing homes in America and more than 50 million have little or no insulation. We are in a position to make a difference. We're the remodeling industry; we must address this!"
Klement and Selby recommend building professionals get educated about high-performance-building technologies through associations, trade shows and others who are doing it. Then create a synergistic relationship between the project team so you can advise each other and find efficiencies in places you may not have thought of alone. Finally, suggest possibilities to clients about ways to improve their homes' energy efficiency. "We find that clients are open to ideas and are looking to us for guidance," Klement says. "Green building doesn't always mean having to spend more money. With things like advanced-framing techniques you're using 30 percent less lumber, and you can advocate smaller spaces that with proper design can feel large. There are things, like solar collectors and geothermal, that will cost more money but that's not what green is all about."
Selby says working with Stern taught him a lot. "Claudette is a very inspiring person and she happened to make us better at our professions, not through direct knowledge but by challenging us to think about things in different ways and ask why. Besides gaining a great friend and doing a very unique project, she was a very inspiring person to work for."
Stern's inspiring nature created the spirit of the project, which led to unique finds, like the attic floor joists and random assortment of windows. "It was uncanny how we would be looking for something and it would appear," Selby says. In fact, long after the team began calling Stern's project the Nautilus House, crew members excavating the backyard discovered a wrought-iron bench whose back support is shaped like a nautilus—a sign, perhaps, that the team was on the right path all along.
For more before and after images, as well as floor plans, of the Nautilus House, visit Gallery.