As homeowners, we’re all looking for more comfort at less cost. The simplest way of getting there is an age-old construction method, revitalized in the 1970s during the oil embargo and forgotten again seemingly until this moment: passive solar.
Instead of fighting nature, you work it to your benefit. Passive solar homes, oriented to use the sun’s energy to naturally heat a home in the winter and reject it in the summer, are flourishing locally.
Single-family homes and apartment buildings are being designed from Lawrence to Lake Quivira, downtown to midtown. They feature thick, heavily insulated walls, superior windows, and in some cases active solar technology.
It’s easiest to go passive with new construction, but David Schleicher of Prairie Design Build has just finished the first passive retrofit in the Midwest, remodeling a 1,900-square-foot, mid-century modern home at Lake Quivira by gutting it inside and out, salvaging materials when possible and reconstructing walls to 16-inches-thick layering as a weather resistant barrier, EPS foam, rigid Styrofoam and rainscreen cladding. Two-foot overhangs and established trees on the south side of the house help reduce heat loads inside.
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“It’s super energy-efficient,” he says. “It’s the most comfortable building you could be in because one of the key principles is super insulation. It has four times the usual amount in the walls, ceilings and floors.”
It also has the best windows money can buy, in this case triple-glazed, krypton-filled ones imported from Ireland — “but you’ve got one chance to do it right,” Schleicher says of the added cost.
Extreme attention to details means there are few opportunities for air to sneak through holes. There’s a condensing dryer, so no vent to the outside, and an induction cooktop, so no gas line coming into the house. Schleicher tore out a large fireplace, which notoriously leaks air, and gained 30 square feet for a built-in media center. He also pulled the HVAC out of the house’s crawl space and heavily insulated the floor. “You want your mechanicals in the thermal envelope,” he notes.
Air tightness might be “the secret sauce,” but there needs to be a counterpoint: the Energy Recovery Ventilator or ERV. “This is the only way for air to get in unless your windows are cracked,” Schleicher explains.
These extra upfront expenses can lead to a 70- to 90-percent savings in energy bills. “At some point, you break even. Seven to 10 years is the national average; it’s all gravy from there,” he says.
Sustainable features are a bonus to the project, but to Schleicher, it’s all about the performance. “We did the math; we dove into how the house will perform holistically, calculating everything from retained body heat to the coffee maker on the front end to determine our true energy usage.”
The home is also solar-ready, so at some point in the future, voltaic panels can snap in easily to the standing seam metal roof and produce all the energy the home needs.
Students enrolled in professor Dan Rockhill’s Studio 804, a graduate-level class at the University of Kansas that designs and builds one modern, sustainable house each year, recently completed a home that incorporates both passive and active solar. The culmination of last year’s class work is a 2,000-square-foot house with a simple form and meticulous details, from the formaldehyde-free and sustainably sourced home products to the maintenance-free exterior cedar siding and native landscape. Additionally, the main floor is ADA-compliant.
The design carefully eliminated penetrations to the outside wall, which is 18 inches thick. Since there is no air transfer through the walls, an ERV performs the job of refreshing the indoor air. High-quality windows — imported from Lithuania to meet the necessary specs for performance — are placed for cross ventilation, with only a small set along the kitchen’s backsplash on the colder, north side of the house.
A solar array of 20 panels generate electricity, qualifying it for Lawrence’s first certified NetZero house, a designation that means all energy needs created in the home are compensated by the home. “On a sunny day, when it’s producing energy but not using it, it goes back on the grid for a credit,” homeowner Marc Epard says. He’s only lived in the home two months; his first utility bill in July was $40; in August it was $33. “Over time, it should average out to zero.”
As a boon, prices on solar panels have dropped significantly. Rockhill says this array might have cost $40,000 just five years ago, but it cost just $10,000. “It’s a long-term investment with a reduction if not elimination of energy bills,” he says.
Axiom House is another such example that is planned, using passive solar and a solar array to create Kansas City’s first NetZero home. It’s a model for a new type of home that challenges current building standards in methodology and technology.
“We said, ‘Let’s do it right’ and threw out all the old practices of design and construction and started from scratch,” says Acres Design president Andrew Dickson. For example, a passive geothermal system will reduce or eliminate the need for A/C, and the walls will be built using airtight Structural Insulated Panels (SIPs) — foam insulation sandwiched by OSB — which are pre-cut off site and installed in a matter of days.
The project is in crowdfunding mode through Indiegogo and slated to be built next summer in midtown’s Startup Village, the first in Dickson’s vision of mass producing NetZero homes around the globe. A handful of floor plans offer options but all are designed to be clean-lined, low maintenance and affordable.
Whereas the price for similar homes is often $300 to $350 per square foot, Axiom House is estimated to come in about $120 to $135 per square foot for an 800- to 2,200-square foot house. Homes will be able to be ordered online Amazon-style, with customers adding features to their cart and the order sent to a warehouse where all the elements will be flat packed and shipped ready to install. “This is the future,” Dickson says.
Single-family homes are not the only structures getting a closer look at outdated construction. A multifamily apartment building prepped to break ground this month in the River Market will be built to Passive House Institute certification, surpassing the more well-known LEED program certification. Sixteen-inch-thick concrete walls will reduce energy loads by about 90 percent.
The two-building complex, called Second and Delaware, is the first of its kind to be built locally and is attracting national attention too. Renters will enjoy the benefits of lower energy bills and a safer building that can withstand extreme weather. The building will also offer its 276 residents rooftop gardens.