Bassett-Dilley founded his firm in 2006 to meld sustainability with contemporary design, grounding his work in region, climate, and context. The firm designed the first certified Passive House project in the Chicago region. Talarico and Smith's home is the third Passive House in the area. The team designed the house, called Acorn Glade, "using the metaphor of the acorn," explains Bassett-Dilley, "so it harmonizes with its site, which includes views to mature oak trees, via a two-level structure that peels back."

Lessons Learned

Initially, the house only had one mini-split, which wasn't sufficient. "We calculated what the thermal bridging would be, so it wasn't unexpected or significant," explains Bassett-Dilley, but "the comfort issues on the lower level were essentially from cold air spillage from the indoor heat pump water heater and lack of a mini-split downstairs." Bassett-Dilley studied the issue, consulted with engineers and manufacturers, then summarized the issue and his proposed solution during his talk at the National Passive House Conference in 2019. 

Instead of a single mini-split, which was unducted and not distributing the warm air sufficiently, Bassett-Dilley had a single mini-split installed on the second floor. "We learned, for future Passive House projects," he says, "that we need to add additional mini-splits, or we need to duct one or two."

Healthy Home Initiative 

The CERV maximizes indoor air quality with air exchanges three times an hour. The homeowners also chose furnishings and finishes that meet the standards of the CDC's Healthy Homes Initiative. 

"We have a little boy whose health is of paramount importance to us, and we want to remain healthy ourselves," says Talarico.

Bassett-Dilley organized the home's interior to the south, which opens to a courtyard-like patio. A backdrop to this opening, which lets plentiful light into the house, is a wall of walnut harvested from trees on site. Walnut from the property was also used in the stairwell. Salvaged wood and concrete floors and stone countertops; no-added-formaldehyde panel materials; no-VOC and non-toxic paints; and GREENGUARD certified sealants, caulks, and adhesives add to the home's superior indoor air quality.

Adding Solar

Initially, says Smith, "solar wasn't part of the equation. It's not required to meet Passive House certification." Having an all-electric house, however, is required. "So, solar was a dream of mine because we also wanted to achieve net-zero."

The home's 36 roof panels produce approximately 1,300 kWh per year and power the house and the family's Tesla. The home has a grid-tied array "because Illinois doesn't allow you to be off-grid," Smith explains. "We do feed energy back into the grid, which is required. I'd like to get battery storage at some point, to keep more of what we generate."

As a PHIUS Source Zero house, monitored results show Acorn Glade uses 86 percent less energy overall, including all household energy use and electric car charging.

Costs and Returns 

Talarico is pleased with her "right-size home. There's very little I would have done differently." Her husband, however, isn't happy about the internal heat pump hot-water heater, as it makes a noise that filters into the family's tv and music room. "I would rather have had an external compressor," Smith says.

He also wishes they would have included solar from the start, "as we would have shifted the exterior and the shed roof to accommodate the solar panels better."

Still, the family is happy with their choice to build a Passive House with solar providing all the energy they need for their electric home. "The cost was about 10 percent more than traditional construction," Smith says, "but part of the idea of Passive House is you're investing in the environment upfront, so you're not paying much in energy costs down the line."