Today, we ran the first blower door test at the MinnePHit House in Minneapolis. The EnerPHit building standard prescribes maximum air-leakage for a retrofit Passive House of 1,0 ACH50 (air changes per hour at 50 Pascal pressure). Converted to CFM50 (cubic feet per minute at 50 Pascals), we were shooting for a magic number of 300 or less. Immediately, the house outperformed this with a reading of 285 CFM. We spent the rest of the morning with help from the Energy Conservatory, Ryan Stegora (builder) and Paul Brazelton (owner) identifying leaks. Some were patched right away—others marked for later improvements. At the end, we measured a steady 267 CFM50, which corresponds to 0.88 ACH50.
We are excited to see that even a 76 year old home can be made virtually airtight, and we are confident that the builder can improve on the performance of this rough-in result for the final test. The Passive House recommendation for retrofits is at 0.6 ACH50 (about 183 CFM50). This means that the home is currently one “Passive House in the Woods total air leakage” from achieving this reach goal.
To put things into perspective, this home started with a blower door result of 8.5 ACH50 and a corresponding 2,100 CFM50 of air leakage. Since then, it grew by almost 40%. Many existing homes we tested over the years in the TwinCities range from 7 to 15 ACH50. According to the Energy Conservatory, average new construction is in the range of 3 – 7 ACH50, with exceptional builders getting down to 1.5 ACH50 on occasion.
We are very pleased with the performance, which also reflects positively on our detailing and specifications.
Minneapolis – The free, self-guided 16th Annual MRES Solar Tour Saturday, October 1, includes open houses at about 50 Minnesota homes, businesses and organizations that have solar and other renewable energy installations. Organized by the Minnesota Renewable Energy Society (MRES), the tour includes open houses in the Twin Cities and several other Minnesota communities from 10 a.m. to 5 p.m.
For the first time, this year the online guide to sites at www.MNSolarTour.org will list each site’s additional eco-friendly features. Besides the usual pictures, maps and details about alternative energy technologies for each site, the guide will list eco-friendly features such as urban chickens, electric cars, rainwater storage systems and the like. Tour guests must register at www.MNSolarTour.org to obtain addresses of the tour sites.
“The solar tour is popular with people who are thinking about purchasing some kind of renewable energy technology because it gives them a chance to see lots of systems and talk to lots of owners,” said Laura Cina, managing director of MRES. “The lists of other eco-friendly site features this year should draw even more people to the event.”
The owner, representatives from TE Studio, as well as representatives from Energy Concepts will be on site during the day to answer your questions.
The 8th international Passive House Days are coming up in November. Once again, the gracious homeowner of the Passive House in the Woods is allowing us to open it up to the public. Join us on November 11 and 13 for two distinctive events.
11/11/11: 6.30-9.00 pm: Friday Night Social: One year in the Passive House, a guided tour, meet the designers, and social gathering.
11/13/11: 10.45-Noon: Public Tour
On Saturday, the owners of the MinnePHit House are opening their doors to visitors to showcase the first EnerPHit project in the country. We are going to showcase the process of what it took to take this 1935 home to the Passive House level of performance.
A conversation on the MinnePHit website inspired me to write a quick summary of why airtight buildings are a good thing. You can find my response to the thread on the MinnePHit website. I will maintain this article on Google Knol going forward.
At TE Studio we are fortunate enough to attract some pretty incredible people. Most recently, we were commissioned by a couple from South Minneapolis to bring their mid-30s home into the 21st century of performance. A brief description of their family reads like this:
Two grown-ups, three girls, two dogs and eight chickens. A 1935 neo-Tudor in Minneapolis, MN. A passion for the planet.
You can see where we are going with this. With ground-breaking in sight, we are looking to make a Passive House retrofit. “Ze Germans” call it EnerPHit—as in energy efficient passive house retrofit.
This means some significant changes—most noticeably to the building envelope, or those bits that separate inside from out. TE Studio is providing the design for this winter coat. We are looking to sustainable materials in an effort to cut the heating demand to about 12kBTUs, or about three hairdryers going at the same time. 9-1/2″ i-Joists will be screwed to an air-tightened sheathing layer on the outside of the current shell, and dense-packed with cellulose insulation for an R-value of 44. Since we are also adding to the back of the house we decided to design a new “hat” for the home. A trussed hip-roof will provide R-77 of cellulose insulation. Even the basement will be insulated to R-values in the 30s. Combined with an airtightness goal of 1.0 ACH50 or better, this retrofit will meet the requirements set forth in the current draft of the EnerPHit standard. According to the German Passiv Haus Institute, this is the first EnerPHit project in North America.
Mechanical ventilation is a good idea for most buildings, but it is essential for any high-performance building. We designed an ERV-based whole house system with an efficiency rating of over 90%. This means that the precious heating energy will remain inside the envelope while the occupants are supplied with outside air year-round. We are able to recycle the home’s existing boiler and continue to heat the home with in-floor heat. The same boiler will also provide hot water. This project demonstrates the amazing potential of a high-efficiency design for existing homes in a cold climate through a great amount of recycling of what is existing—paired with carefully selected sustainable materials and methods for the retrofit and what is new.
The design is complementary to the building’s origins and surroundings. An open first floor plan will provide much needed space for the family, and offer a connection with the backyard. On the second floor we are adding bed rooms for the kids and an additional bath. At just over 2,000 finished square feet (counting the basement), this is no mansion for 5 people and two dogs, but with its well organized layout, it will be incredibly functional.
We are very excited about this project. The owners are offering updates on the project at http://www.minnephithouse.com
Only one question left to ask: What do the chickens think of this?
Synergy is a beacon for the 21st century renaissance of residential high-performance design. It is built on the world’s leading energy efficiency standard—Passive House. Within a building envelope that is designed to minimize maintenance cycles and age gracefully, it provides highest levels of comfort and healthy day-lit interiors. Synergy’s combination of amazing performance and built-in energy conservation make it a leapfrog performer that will save you money month after month, year after year. The extremely reduced environmental footprint and extensive use of green materials combine with highly functional floor plans and beautiful, customizable design to compliment your lifestyle.
Synergy is the essence of holistic design for sustainable homes. Welcome to Synergy. Welcome Home.
Download the brochure: Synergy Flyer Web
Talk to us about your project: firstname.lastname@example.org
Join us on May 7 and 8 at the State Fair Grounds for this year’s Living Green Expo. We’ll be in the Education building, in aisle A and booth 04. We are going to showcase our holistic approach to sustainable building design. Among other things, we’ll offer an insight into affordable high-peformance designs that cut 80% of operations cost and stretch maintenance cycles by a factor of 2 and more. On Saturday, I will be lecturing at Noon about Passive House. See you!
I’ll be at the U of M tomorrow, 4/19/11 from 11.15 to 12.30 at Rhapson Hall to lecture on the basics of Passive House and sustainable design.
I will be at the Corcoran Park Neighborhood Sustainability Event tomorrow, February 12, 2011. From 11 am – 12.30 pm I will be lecturing on Deep Energy Reduction Retrofitting. You can find out how a retrofit can bring 21st century performance to your home.
3334 20th Avenue South
Minneapolis, MN 55407
Open to the public.
North Hennepin Community College invited me to share the stage with Dr. Konkol—the owner of the Passive House in the Woods. Dr. Konkol and I will be discussing our experience with the Passive House project, and inform and educate young people to consider energy efficient housing as they begin planning for their own projects.
As part of the same event at NHCC, Will Steger is presenting as a keynote speaker on Monday, April 18. He will be speaking on his polar experiences and on energy efficient housing. We’ll be able to tie into his lecture with Dr. Konkol’s house.
Please save the date: April 20, 2011 from 10 – 11 AM at North Hennepin Community College. Details to follow.
I will be lecturing at a Passive House Minnesota event on February 3, 2011. Please find the specifics at phmn.org. I’ll be talking about the Passive House building energy standard, as well as the Passive House in the Woods. I’ll be joined by PHMN board members, as well as Josh Crenshaw, who built the Passive House in the Woods. I also expect vendors to showcase their PH-specific products at the event.
The Hudson Star Observer followed up with Gary Konkol this week to see how he’s doing in the house without furnace. Read the entire article here.
I’d like to add that $25.25 of Dr. Konkol’s electricity bill goes to the service fees, which means the actual cost of electricity consumed in November was only about $35. It will be interesting to track this over a year and report back an average, since these winter months are going to be more energy intensive than the swing seasons and the summer. In addition, November was incredibly cloudy in the Town of Hudson, leading to very little energy production. And before I forget to mention it—the electricity bill is the only utility bill at the house, so the $35 included the entire energy purchase for heating, ventilation, hot water, and household electricity.
One of the frequently asked questions I get about Passive House is its potential for going off the grid. I summarized different levels of energy independence in a Google knol.
Passive House buildings use very little energy to begin with. Therefore, it is a lot easier to utilize renewable energy sources such as solar or wind to offset a Passive House’s energy use. Renewable systems are much smaller than they would have to be for standard construction buildings, which saves investment cost.
Many different energy sources are a viable option for Passive House because of tis inherently small energy footprint. This make Passive House buildings very flexible and future proof.
One of the key goals of Passive House is to insulate the owner from an uncertain energy future. The buildings we build now will likely be around for 50, 100, or more years. Therefore, they will have to function in an era where the fuels we commonly use now may no longer be viable. That point may be reached long before the actual resource is consumed, as pointed out by former Saudi Oil Minister Sheikh Yamani in 1973: “The stone age didn’t end because we ran out of stones.”
Anytime I speak to people about Passive House there seems to be some confusion with the Passive Solar Design ideas from the late 70s. I created a quick outline to compare the two and show which is what: Passive House vs. Passive Solar Design at Google knol.
Join us during the 7th international Passive House Days on Friday through Sunday. We will open the Passive House in the Woods for public viewing from 10 am to 4 pm each day. Gary Konkol (owner) and Tim Eian (TE Studio) will be on site to answer your questions and demonstrate how the home functions with every day use. We look forward to seeing you in Hudson.
Mary James at Lowcarbonproductions just published her second book on Passive Houses in the U.S. called “Recreating the American Home”. I am happy to announce that the Passive House in the Woods project is one of the feature projects in the book. You can find more info and purchase the book here.
I’ll be presenting the Passive House in the Woods at the 5th North American Passive House Conference on Saturday, November 6th 2010, time t.b.d.
You can find more info and register for the conference at the Conference Website.
All my upcoming and past speaking engagements can be found in the Portfolio/Lecture section of this website.
The U of M’s Bell Museum in partnership with the Center for Sustainable Building Research invited us to participate in their latest exhibit, Sustainable Shelter—Dwelling within the Forces of Nature. The exhibit will show the many ways that animals and humans create shelter, and explain how shelters relate to the environment. Doors opened this past weekend and the exhibit will be on through May 15th. The grand opening is November 11. Find the CSBR’s press release at this link.