Passive House is more than an energy standard—it’s a way of understanding the technology of high-performance building, and it allows architects to optimize a building’s performance through the design process, regardless of whether an owner wants to pursue certification or not.
The “business-as-usual” approach to design is to focus on program and appearance, then have an engineer or contractor size mechanical systems to condition the building; more sensitive designers may take into account sun angles and daylighting, but for many designers these are afterthoughts as well. That approach usually leads to needless energy consumption, glare, overheating, and thermal bridging. Our approach is to use the powerful Passive House modeling tool to tune the building to the climate as an integral part of the design process.
We begin design with an analysis of climate (temperatures, humidity, sun, rain/snow, wind), vistas and sense of prospect or “belonging” on the site, topography, and neighborhood or natural setting, all to allow the building to speak the language of the site. I think of it as imagining a living thing that evolved to live in that place—its feet or roots in the ground, its back to shelter, its face to the sun, with the right brows, whiskers, or foliage, as the metaphor may be!
That leads to initial gestural designs that become building shapes. As soon as we settle on a general layout, we then bring that geometry into our Passive House (PHIUS) modeling software (called WUFI-Passive), where we can enter values for insulation, window size, orientation, and performance, mechanical system performance, and internal energy use. By trying out different values for these, and by trying different approaches to shading and exposure, we can arrive at an optimal performance level for the building.
Part of the beauty of the PHIUS standard is that the climate-specific metrics give definite targets to design toward. When we optimize for both heating and cooling loads, we set the stage for comfort; when we minimize overall energy (efficient mechanical system, lighting, and appliances), we can design a project to meet annual net zero energy with the smallest solar PV array possible. And from a design point of view, we know the building will have a climatic “fit” that will allow the building to feel true to place.
If there’s one absolute I go by, it’s that Nature is right. I use the PHIUS tools and knowledge to allow my designs have an organic approach to energy, just as I employ biophilic design and understanding of the locality to allow the designs to have an organic, natural countenance and fit with the site. We’re pursuing ecological architecture through both art and science.
For those of us trying to radically push energy efficiency ahead, a strong incentive program can be a blessing. That’s what we now have with the Illinois Clean Energy Community Foundation. Their Net Zero Energy Building Program provides grant money to non-profits, local governments, and colleges/universities undertaking building to site net zero, typically through Passive House or Net Zero/ILFI Certification. Years ago they would provide funding for LEED projects, but as LEED became more common and the need for energy efficiency more urgent (and attainable!), they raised the bar from LEED to Zero Energy. This is huge—we are seeing an amazing increase in PHIUS buildings: aside from our Park District project, there are at least three other schools and park buildings in construction or design as I write this. Given that the only other PHIUS certified projects in the area at this time of writing are our TBDA designed ones and one affordable multifamily project (Tierra Linda), this is a big deal. It’s also a bit worrisome: for the designers and contractors taking this on for the first time, there will be lessons learned and probably some bumps in the road, just as we’ve had on our projects.
To put this into perspective: we just received grant approval for our Carroll Center project, a retrofit and addition for a park district building that will accommodate preschool, after-school, and adult class programming. It’s about a $1.7M build, and the grant of about $577,000 covers the complexity of the retrofit construction (a gut rehab to eliminate thermal bridges, add insulation, replace windows, and redo mechanical systems), upgrade the new addition to Passive, and cover the certification costs (for energy modeling, rater work, and PHIUS review and certification). Without the grant, the park district would not have been able to justify the costs. So, a big thank you to ICECF!
TBDA’s vision is to design a healthy, beautiful, low-carbon future.
We’re a service profession, so the core of what we do is design buildings where people live, work, and play; but our vision is the attitude and purpose we bring to that service, the reason you would hire or work for us instead of the next firm.
Let’s look at these values—healthy, beautiful, low-carbon–in a little more detail. How do we incorporate these into our work?(more…)
The Passive House Institute US reviews the metrics and rationale of their standard on a three-year cycle. PHIUS+ 2018 was announced at the Passive House Conference in Boston this September, and I find it a brilliant and positive advancement.
Keep in mind that the Passive House Standard prioritizes energy conservation, so its main measure is the annual and peak consumption of space conditioning (how long and hard the mechanical system needs to work). When PHIUS+ 2015 was announced, it was noted that the space conditioning metrics were set so that the amount of insulation required to meet the standard would be beyond the cost-optimized amount; the 2015 standard was pushing hard on passive conservation. (more…)
There’s a terrific video my buddy Corbett did for the Illinois Association of Energy Raters called “If Cars Were Built Like Houses.” It challenges homebuyers to think about what level of performance they will get out of the huge investment they’re about to make. What if houses were built like cars—in a factory, with quality control and third-party testing? That’s how we approach modular prefab—a way to get a better, more predictable product. The first thing to know is that a modular prefab house can be a “trailer home” or it can be a high-design high-performance, low-toxicity (no “new car smell”) home. (more…)
It’s our favorite tour of the year, the Green Built Home Tour, and our Modular Prefab Modern Farmhouse will be featured on this year’s tour on July 28-29, 2018. Our amazing clients, Nate & Deb, will open their new home for visitors to tour their innovative, prefab, modular, Zero Energy Ready Home (DOE). Tom will lead tours and answer all your questions about prefab and green design.
Tickets are available for purchase on the Green Built Home Tour site.
The modular prefab “Modern Farmhouse” was designed by TBDA, with module construction provided by Hi-Tech Housing in Bristol, Indiana. The six modules were shipped to the site and erected in one day, with finishes and fixtures being installed on-site by Himelick Contracting. Tom Bassett-Dilley and Eco Achievers led this mid-construction tour, where they described modular prefab process and how the DOE Zero Energy Ready Home program ensures energy efficiency, indoor air quality, and durability.
On a perfect late summer day we invited a bunch of friends to watch our first modular prefab house being set.
First off, some terminology: prefab is anything factory-built, so it could be trusses, walls, floors; but modular is when “chunks” of the building (or the whole thing if a tiny house) are built in the factory. We were interested in the efficiency and quality control of prefab, and with modular, we could get windows installed, rough electrical wiring, rough plumbing, air sealing (by using the Zip System for sheathing), cavity insulation, and drywall all done in the factory. In our case, we worked with Hi-Tech Housing of Bristol, IN since they are specifically a custom modular manufacturer, No stock plans here–you just take them whatever you’re interested in building, and they help figure out how to break it into chunks that can be transported on trucks. Once the modules are ready, a “set crew” and crane operator are hired to put it together in the field. (more…)