Five years ago, architect Kevin Flynn put his belief in environmentally sound building into practice professionally: After spending 25 years working at a variety of large and small architectural firms, he struck out on his own and founded EcoDEEP, a green architectural firm based in St. Paul, Minn. However, Flynn still felt he wasn’t fully living his vision. To truly practice what he preached, he reasoned, his home and office also had to be exercises in sustainability.
In 2008, Flynn and his wife, architect Roxanne Nelson, undertook an ambitious project, dubbed EcoDEEP Haus, to transform a 1940s bungalow into a livable model of sustainable design. Scouting potential locations for the project, Flynn and Nelson were determined to stay in the city. “We wanted to demonstrate that one can use existing housing and, rather than moving out to the suburbs, stay in a viable neighborhood with existing infrastructure and lots of intangible amenities, like being able to walk everywhere,” Flynn explains. “We wanted it to be as much a proof project as anything else, to show that it can be done.”
The house they settled on was a 1,700-square-foot Cape Cod structure in the city’s Highland Park neighborhood, about a half-mile from the Mississippi River and within easy walking distance of schools, shops, and public transportation. The one-and-a-half-story home had been well-maintained, but the couple desired an updated kitchen, additional bedrooms for their three children, and more open and flexible common areas suitable for entertaining, along with energy-saving features and sustainable materials throughout.
To reduce construction waste and keep the overall footprint of the home small, Flynn and Nelson worked closely with a structural engineer, a contractor, and energy modelers to design a structure that preserved the original foundation of the house, as well as most of the main floor. They expanded upward, removing the original gabled roof and building out a second story, along with a modest 620-square-foot addition on the northwest side. The resulting high-performance, energy-efficient, 3,200-square-foot home boasts four bedrooms, an office for Flynn on the main floor that can double as a large fifth bedroom, and two and a half baths. Remarkably, EcoDEEP Haus uses 40 percent less energy than the original home, at nearly double the size.
The efficiency gains result from the effective use of insulation—cell spray foam and blown fiberglass contribute an R-value of 60 in the roof cavity, while the rim joists and walls are insulated to R24—combined with passive solar and solar panels. Smart window positioning brings in abundant natural light and enables passive heating in winter and cooling in summer. Smaller, triple-glazed, low-E argon fiberglass windows and fixed wooden sunshades on the home’s southern face prevent strong summer sunlight from heating the interior, while larger windows on the opposite side of the home allow ample cool northern light to filter in. In the winter, the sun’s lower position in the sky enables sunlight to sneak below the sunshades, resulting in a passive warming effect. “We hardly ever have to turn the lights on in the house,” Flynn says. “It’s very bright and comfortable inside, but there’s no solar gain.” At night and on overcast days, fluorescent and LED light fixtures keep energy use (and costs) low.
Rooftop solar panels provide both electricity and hot water for EcoDEEP Haus. A 1.44-kW photovoltaic system, consisting of eight 3-foot-by-5-foot panels, generates about 30 percent of the home’s total electricity supply. (The original plan called for a 2.44-kW system, but additional expenses elsewhere necessitated scaling back on the PV system.) Two 4-foot-by-8-foot solar hot-water panels heat water in a 90-gallon thermal storage tank. From May to October, the system supplies all of the home’s hot water needs; during the long, cold Minnesota winter, it still provides about 40 percent to 50 percent of the hot water the family uses.
Another feature of EcoDEEP Haus is its green roof. A 4-inch-deep mat of vegetation covers half the roof; the other half has a white reflective cooling membrane. Apart from designing the roof structure to carry extra weight, Flynn says executing the green roof was easier than expected. The LiveRoof system he used was simple to install and requires little maintenance, aside from occasional weeding. “[The modular tray system] goes in easily and takes root,” he says. “It looks just gorgeous. Nobody sees it but me, but the birds love it. It’s a nice ecosystem for birds and bees and butterflies.” The green roof absorbs much of the rainfall that otherwise would flow into the city’s stormwater drains, while the rest is collected in rain barrels that the couple uses to irrigate their lawn and garden.
The home’s interiors echo the angular look of the exterior, whose lower half was re-clad in FSC-certified fiber cement board siding while the second floor is outfitted with durable corrugated metal siding. Energy-efficient fixtures and appliances—including a 92-percent-efficient furnace and 86-percent-efficient gas water heater—further reduce the home’s carbon footprint. Low-flow fixtures and dual-flush toilets reduce water use by 64 percent over other homes of a similar size.
To complete the interior, Flynn and Nelson used local and recycled materials whenever possible, as well as low- or no-VOC paints and adhesives that preserve indoor air quality. “We didn’t want the materials inside our house to make us sick,” Flynn says. Sustainable finishes range from recycled glass terrazzo and recycled paper countertops to salvaged oak flooring and reconstituted wood veneer cabinetry faces.
The challenge of transforming an existing structure into an eco-friendly dream home, at a cost of less than $140 per square foot, was exacerbated by the project’s compressed time frame—the design process was completed in two months and the renovation in five months. “In any kind of remodeling project, you’re never quite sure what you’re going to get into when you tear open a wall. Where we expected there would be insulation, there wasn’t any. Where we didn’t expect there to be, there was,” Flynn says. “We were just one step ahead of the contractor every day. The challenge was keeping up with ourselves. We found out you could do it if you weren’t overly dependent on sleep.”
The project is already receiving both local and international attention in addition to its win in the Greenhouse category of the 2009 Evergreen Awards. AIA Minnesota and Mpls.St.Paul magazine honored EcoDEEP Haus with a Residential Architects Vision and Excellence Award, and the Minneapolis Star Tribune will feature it as a 2009–10 Home of the Month. Discovery’s Planet Green network also plans to include the home in a show on the world’s greenest homes that will air this fall.
“When you can double the size of the house and use less energy than before, that’s impressive,” Flynn admits. “And we’ve done it in a way that’s sleek and modern and new.”
Architect, interior designer, client/owner: Kevin Flynn and Roxanne Nelson, EcoDEEP, ecodeep.com
Mechanical engineer: Seasonal Control, seasonalcontrol.com
Structural engineer: McConkey, Johnson Soltermann, mcconkeyjohnsonsoltermann.com
Electrical engineer: Electrical Visions, electricalvisions.net
Construction manager, green consultant, LEED consultant and/or life-cycle performance partner: Kevin Flynn, EcoDEEP
General contractor: Michlitsch Builders
Landscape architect: Matthew Fair Jones, Fair Design, matthewfairjones.com
Lighting designer: Roxanne Nelson, EcoDEEP
Energy modeler and rater: Neighborhood Energy Connection, thenec.org
Photographs: Gilbertson Photography, gilbertsonphotography.com
Materials and Sources
Adhesives and sealants: OSI GreenSeries, Henkel Corp., greenseries.com
Refrigerator: Jennair, jennair.com
Cooktop, oven, microwave, dishwasher: Bosch, bosch-home.com/us
Cabinetry: Eastvold Custom Woodworks, eastvoldcustom.com
Carpet: FLOR modular carpet tile, Interface, flor.com
Ceilings: Gypsum Board, USG, usg.com
Concrete, masonry: Buckcrete, locally sourced, 25 percent fly-ash
Wood flooring: Salvaged and refinished from existing house and locally sourced FSC red oak with dark stain, Hovland Lumber
Furniture: Existing; IKEA, ikea.com
Glass: Profilit Pilkington, Technical Glass Products, tgpamerica.com; WL Hall Co., wlhall.com
HVAC: Amana 92 percent FA furnace, amana-hac.com
Lighting control systems: Lutron dimming systems, lutron.com
Millwork: Skyblend, Certified Wood Products, Dan Haugen, certifiedwood.net
Paints and finishes: Pure Performance, Zero VOC, PPG, corporateportal.ppg.com/ppg
Pavers: VAST Enterprises, vastpavers.com
Roofing: Fully adhered membrane roofing, Firestone UltraPly TPO, firestonebpco.com/roofing/tpo/ultraplytpo
Sheathing and framing lumber: Roseburg Rigid Floor, FSC Lumber
Green roof: LiveRoof, Bachman’s, liveroof.com
Metal roof, corrugated metal siding: Metal Sales, Image II Standing Seam Galvalume, mtlsales.com
Siding: HardiePlank, James Hardie, jameshardie.com
Site and landscape products: Local and native grasses and plantings
Windows, curtainwalls, doors: Inline Fiberglass Windows, inlinefiberglass.com
Heidi Moore writes about architecture from Chicago.