Full story: Take a walk through an old Hyde Park graystone being retrofitted for “Passivhaus” certification
How can this energy efficiency standard become as common in Chicago as the kind of house it’s being applied to?
Earlier this month I toured what will most likely become the first Passivhaus Institut-certified building in Illinois. The extremely airtight, single-family house is for sale in Hyde Park, across from the University of Chicago dormitory designed by Studio Gang.
Being a “passive house” means it will use less energy per household than all of you reading this article — unless you also live in a passive house. Energy efficient houses don’t really appear like they’re going to be extremely energy efficient, and since the one at 5485 S. Ellis Ave. is a retrofit of a 134-year-old row house, it won’t look that way at all.
Mike Conners bought the house in 2015 and has been renovating it since then. He’s renovated other houses in Kenwood and Hyde Park, after spending most of his career as a financial investor. Conners is working with architect Richard Kasemsarn, head of his own firm and a professor at the School of the Art Institute at Chicago, to design the retrofit.
Passivhaus Institut is a German organization that educates contractors and property developers about the PH standard they’ve developed, and trains companies on how to measure and certify buildings. Conners said that PHI “suggests a ninety percent reduction in build energy demand should be expected all else being equal versus existing” use.
During the tour it became easy to see how this house will, as projected, use less than $2 worth of electricity, to heat and cool the house, per day. (The house will only have a natural gas line hookup to power a small emergency generator.)
As part of the passive house standard’s focus on reducing building-related energy loss, the walls of the Ellis house were enlarged on both the interior and exterior to add insulation. Insulation isn’t enough, though: “thermal bridging” is eliminated. Hot and cold can be transferred through wall studs and window mullions and decimate a building’s energy peformance.
When you get up close to the exterior of the house you’ll notice that the graystone’s masonry exterior has been covered in fiber cement siding, which protect exterior insulation and are made with cement and cellulose fibers.
There are seven climate controlled zones, each with its own silent Mitsubishi “mini split” that is also ducted to a Zehnder heat exchanger, which circulates air between the interior and exterior. Occupants can also set the mini split to cool the interior air in a zone.
Passive houses aren’t only about energy efficiency; the certification also dictates air quality and health standards. Numerous intake valves are embedded in every room of the house to remove air, filter it at the Zehnder, recovers the heat from stale air, transfers it to colder fresh air (pre-conditioning), and replacing the air through the mini splits.
Other health standards include using products that do not have toxic chemicals in them; paint cannot have volatile organic compounds (VOCs), for example. Preventing mold is another outcome of these systems.
The real energy efficiency of a house isn’t because of new or better appliances, however. Conners said, “Energy efficient appliances and technologies were very important to me then [in 2007, when he renovated the Nathanial Butler House] as was preservation, but I really knew little of building science, global warming, zero energy design. A reliance on energy efficient toys won’t get mankind where it needs to go. It’s the envelope — the building shell, a shell that lasts generations.” (Read more about the Ellis house’s envelope.)
Conners showed me some of his research, which is part of the documentation needed to obtain Passivhaus Institut certification, that demonstrated the projected energy use and how that compared to another graystone in Hyde Park. The energy data for the comparison house was found on the MLS real estate listings database.
The other graystone had used nearly $6,000 in natural gas and electricity annually, and Conners projected $1,500 for the Ellis house. (Both figures include TVs and computers, a dishwasher, refrigerator, and laundry.)
The primary way that a passive house is tested to achieve certification is by using a blower door test. A special door is installed in place of the house’s front door and hermetically sealed. It pulls air out of the house and the test is conducted before and after the renovations to determine their effectiveness in reducing “leaks” in the building envelope.
Conners also plans to add photovoltaic solar panels on the roof, in view from the new rooftop deck he added. He predicts electricity from the panels will make the house “net zero”, meaning it generates more electricity than it consumes; it won’t be off the grid, however, unless he installs battery packs to supply electricity overnight and when the sun is behind clouds.
I had only planned to tour the future passive house for about an hour, but it was an impressive project, and one hour turned into two. A friend of mine who’s an architect came, too, and we both wanted to know a lot. I’m excited about the prospect that Chicago will have the first house in the state certified by Passivhaus Institut, as I hope it will encourage more home buyers and builders, as well as city officials, to adopt the standard.
Part of the excitement was seeing many of the components, like the fiber cement panels, for the first time. One of my favorite components are the dual-mode “tilt turn” windows that I’ve seen in houses all over Europe (the ones at the Ellis house also have triple panes).
It gets colder and hotter in Chicago than most of Germany. Illinois generates less energy from renewable resources from wind and solar than in Germany and other countries. However, Illinois has a higher potential than Germany to generate electricity through photovoltaics, and Lake Michigan has a high potential to generate power from the wind. That, coupled with building inefficiencies, should be the impetus we need to waste less of our coal and nuclear energy resources.
Mike Eliason, a passivhaus designer in Seattle with Patano Studio who has worked in the US and Germany, said that American energy codes are less strict than German ones, “so partially they were more predisposed” to adopt a passive house standard. He added that the KfW development bank, owned by the federal and state governments of Germany, provides economic incentives for energy efficiency through low-interest loans.
“Add in the push of the European Union energy performance of buildings directive towards nearly zero energy buildings — and an ecosystem has popped up that supports this”, Eliason said. That ecosystem includes over 900 certified components, but few are made in the United States. The Ellis house’s fiber cement boards came from Finland.
Increasing the availability of passive buildings is tough. Eliason thinks the biggest hurdle “to uptake is lack of knowledge and awareness coupled with low energy costs”. On a self-reporting database of passive house buildings, there are 46 certified buildings in the United States, when there are nearly 500 in Germany and more all over Europe. Passive House Institute in Germany said in 2016 there are over 60,000 passive buildings worldwide.
Chicago’s sustainable development policy requires a minimum of sustainable building elements in all planned developments, projects that receive $1 million or more in TIF funds, and affordable housing projects that receive certain grants. New construction projects must achieve 100 points on the city’s SDP matrix; Passive House certification nets only 70 points while LEED certification levels score higher. Two architects familiar with sustainability standards I talked to would have given Passive House certification a higher score, because of its focus on testing energy performance.
Can a smart architect & developer team design the next great three-flat design for Chicago that can also be easily replicated? It should have equal parts efficiency and aesthetics, is remarkably efficient in the winter, resilient to increasingly strong rainstorms, and architecturally pleasing to become the ubiquitous “Chicago-style” house. A new generation of houses for future Chicago families like the thouands of two- and three-flats that were built for Chicagoans between 1900 and 1918.
Take action
Something any owner of a single-family house or condo, or small multi-unit building can do, is get a low-cost energy assessment from Elevate Energy (in Cook County) or a contractor via Energy Impact Illinois. An expert will come and review your building and recommend some renovations. Rebates and tax credits are available. Interested homeowners, and renters with their landlord’s permission, can ask ComEd for free LED bulbs and water savers.
If you’re interested in solar panels, check out Cook County’s community solar initiative, and the solar map of Cook County.
