Hope you can make it!
Hope you can make it!
Our Ballard net-zero-energy house is not just in Ballard anymore. Mark and Diane Leganza are about to move into a house built to almost the same plans as ours on Whidbey Island.
Attendees of the recent SICBA Home Tour got a close-up look at their home, which is projected to be net-energy-positive, just like ours. Unlike our home, however, this one is decidedly rural, set in a beautiful treed lot. Because they weren’t restricted by the setbacks of a small urban lot like ours, they were able to build the wraparound porch that the design originally called for and a large workshop/garage. I only have a few photos, but the house looks great amongst the trees.
Unfortunately, we weren’t able to attend the tour, and we were out of town Mark and Diane did a walkthrough of our house a couple of years ago, but we want to congratulate them on their almost-completed project.
The house was built by Ted Clifton Sr., who sells a full builder’s set of plans for just $1,275. We’d love to see more people build this affordable, high-performance design in other parts of the country as well.
The Leganzas have a blog detailing the building process.
We want to congratulate our builder, Ted Clifton Jr., for winning a prestigious national award for our home. The U.S. Department of Energy’s Housing Innovation Awards recognize the very best in innovation on the path to zero net-energy ready homes. The designer of our house, Ted Clifton Sr., also deserves much credit for helping our house perform so well.
Interestingly, our house won in the “Affordable Builders” category. I see it as a real testament to Ted Sr.’s innovative design and Ted Jr.’s cost-control chops that our net-zero-energy custom home was able to compete and win in a category filled with public housing projects and Habitat for Humanity houses. Way to go guys!
Check out what the US Department of Energy had to say (or go to the full article here):
The owners of a U.S. Department of Energy Challenge Home in Seattle, Washington, are so excited about their high-performance net zero energy home they have become “energy evangelists,” blogging about the design and construction process, organizing a series of community talks on sustainability, and hosting several local green home tours since construction started in 2011.
Homeowners Eric Thomas and Alexandra Salmon are not the only ones excited about this ENERGY STAR-certified, 5-Star Built Green home, which is one of Seattle’s first true net-zero energy homes (a home that produces as much electricity from the sun as it uses over the course of a year). The home has garnered a lot of media attention from local TV and radio news shows and newspapers and national magazines and web sites as well.
Thomas and Salmon didn’t set out to become local green celebrities. The newlyweds were just looking for a house to buy and couldn’t find anything they liked in their price range. When they came across an empty lot for $180,000 in the Ballard neighborhood of Seattle, they decided to build.
A search for house plans turned up Zero Energy Plans LLC, a design firm started by pioneering zero energy home builder Ted L. Clifton who builds highly energy- efficient custom homes on and around nearby Whidbey Island in the Puget Sound. The couple was very attracted to the idea of building a home that produces at least as much energy as it consumes. Clifton encouraged them to also go for a DOE Challenge Home certification on the home. Clifton was one of a group of builders who provided suggestions to DOE for formulating the Challenge Home program. He has committed to meeting the Challenge Home criteria on all of his new homes.
The home was built by Ted L. Clifton’s son, Ted W. Clifton, whose Bellingham, Washington, firm TC Legend Homes is gaining a reputation for highly efficient green construction. The couple selected a design for a three-bedroom, two-story 1,915 ft2 home with an open floor plan. They asked Clifton to modify the plans slightly to let in more light and to save on construction costs. For example, they didn’t build a garage. The couple didn’t even own a car when construction started and on their small urban lot, the only available spot for a garage would have been underneath the house, which would have required the considerable added expense of excavation.
Instead of a basement, they chose a slab foundation. The builder applied an acid stain to the concrete, which resulted in a beautiful, durable floor that saves on flooring costs and works well with their in-slab radiant floor heating. The concrete also acts as a thermal mass to absorb heat from the home’s many south-facing windows during the day, providing a source of passive solar heating.
The radiant heating system consists of PEX tubing in the first-floor slab, which circulates water that is heated by an air-to-water heat pump. The 3-ton heat pump has a capacity of 35,400 Btu/h with a heating efficiency HSPF (heating season performance factor) of 9.2 or a COP (coefficient of performance) of 3.0 to 5.5. Thanks to the home’s open design, well-insulated shell, and air-mixing ventilation system, this first-floor hydronic heating system is all that’s needed to keep even the second-floor bedrooms warm, with the exception of a small electric-resistance in-floor heating mat in the upstairs bathroom.
The air-to-water heat pump also preheats the home’s domestic hot water. The hot water system has three tanks: the first tank (a standard 50-gallon water heater with its element removed) is kept at a constant 105 degrees by the heat pump; it serves as a reservoir for the radiant floor and the rest of the system. When needed, a small circulating pump sends hot water from the first tank to the second tank. The second tank acts as a heat exchanger that preheats domestic water before it enters the third tank, a standard electric-resistance hot water heater.
The home’s building envelope is insulated and air tight to levels approaching Passive House standards. The slab-on-grade foundation is separated from the ground by four inches of extruded polystyrene (XPS) rigid foam, providing an R-20 insulation value. Two inches (R-10) of XPS rigid foam insulation covers the exterior of the foundation walls down to the footing.
The walls and roof of the home are composed of structural insulated panels (SIPs). For the walls, these panels consist of two pieces of OSB sandwiching a 5-5/8-inch layer of rigid expanded polystyrene (EPS) that, together with siding and drywall, provides a total wall insulation value of R-26. The walls are covered with a corrugated house wrap that provides a drainage plane and a slight air gap for ventilation. The home is sided with durable, rot-resistant fiber cement siding.
The EPS roof is built with thicker 10-1/4-inch SIP panels providing an R-41 insulation value. The SIPs are manufactured locally in a factory 30 miles south of Seattle and come to the site precisely cut for the home design, which enables quick assembly with much less construction waste than is typical of site-built framed walls.
Windows can be the weak spot in a home’s thermal envelope, but the builder selected high-performance triple-glazed windows sourced from a company in nearby British Columbia. The windows’ vinyl frames have extruded internal chambers that provide thermal breaks for insulating properties allowing them to outperform many more expensive wood- and fiberglass-framed products. The windows have an insulating argon gas fill between the glass panes and the glass is covered with an invisible low-emissivity coating to minimize winter heat loss and summer heat gain. The windows have a rare combination of low U factors (U=0.15 to 0.20) meaning they are highly insulating, and a high solar heat gain coefficient (SHC=0.50) meaning they let in a lot of solar energy, which is important for a home designed to make use of passive solar heating.
Clifton recommended against a heat-recovery ventilator (HRV) and instead incorporated a balanced ventilation system that he has used successfully in several homes in the Northwest climate. The system makes use of several exhaust fans: one in each bathroom, the laundry room, and the kitchen. The exhaust fan in the upstairs bathroom is motion-activated; it runs steadily at a low rate and ramps up when someone enters the room. When the powerful exhaust fan in the kitchen is switched on, it also activates a supply fan that brings fresh air into the home from outside, sending it through a HEPA filter and to all three bedrooms and the living room. “We keep the house at 69 degrees in the winter, and the air stays at a comfortable 55% relative humidity,” said Thomas.
The home has no air conditioning and, in an August 2013 blog post, Thomas wondered, with all the south-facing windows, “would we find ourselves baking in our personal greenhouse in the summer?” But the homeowners have been pleasantly surprised to find they can stay cool, even without resorting to running the heat pump in reverse to chill the floors, thanks to a simple trick Clifton showed them. They leave the windows open to let in the cooler night air and turn on the exhaust fan in the kitchen (which also activates the powered HEPA ventilation system) for about 15 minutes first thing in the morning. When the outside temperature starts to rise at midday, they close the windows and lower the double-honeycomb cloth blinds; the indoor temperature stays low all day without any air conditioning. This technique is especially suited to the Northwest’s dry summers with cool evenings.
All of these energy-efficiency measures have added up to a house that performs remarkably well from an energy standpoint. Even without counting in the solar panels, the home earns a home energy rating system (HERS) score of 37 and would have projected utility bills of about $740 a year. For comparison, a home built to the 2006 IECC would typically have a HERS score of 100 and the average HERS score for typical older homes is 120. With the 6.4-kW photovoltaic power system installed on the roof, the home’s HERS scores drops to -1 and utility bills for the all-electric home drop to zero. The home has actually performed better than predicted, hitting zero on the net electricity meter three months ahead of schedule. By January 2013, after 15 months of living in the home, the home owners had a credit of $230 with the utility company. They chose to leave it in their account to cover winter months (November through March) when the bi-monthly electricity bills could get as high as $90. In contrast, from March through October, bimonthly bills ranged from -$12 to -$125.
With a custom design, high-end appliances and equipment, and so much performance, one would expect the price tag to be pretty steep but the very average price is one reason the unique home has attracted so much attention.
The cost to build was only $124/ft2 (or $114 if you count the rebates and incentives), whereas the average cost for new residential construction in Seattle is $200/ft2. The $124/ft2 included the costs for design, construction, materials, PV system, taxes, and permits (which totaled $237,000, including $32,696 for the PV system before rebates). The land cost $180,000. After subtracting a $9,000 federal tax credit for the PV system, and $9,000 for state solar production credits (paid out over 9 years), the total came to about $399,000. On top of that, the homeowners won’t be paying for utilities, which come to about $150 per month, or $1,800 per year, for the average Seattle household.
“Now that we’ve lived in the house for a year, we’ve found it to be warm in the winter, cool in the summer (even without air conditioning), and comfortable overall. By keeping the design simple and minimizing expensive finishes, we were able to keep the cost of building down … we think our project demonstrates building green need not cost more than traditional construction. Now that we have settled in, we hope to play a role in inspiring others to build or retrofit existing Seattle homes to the net-zero-energy standard,” said Thomas.
If you’re planning on attending the upcoming BuiltGreen Conference, Nov. 6, in Woodinville, WA, be sure to check out the panel I’ll be speaking on. Spoiler alert: ours is one of the houses that succeeded in reaching its net-zero-energy goal.
Online registration is here. Hope you can make it!
Zero Energy Homes: Evaluating Post Occupancy Energy Performance
Eric Thomas, Senior Copywriter, IOOC and Publicity Coordinator, Sustainable Ballard
George Ostrow, Founder, Velocipede Architects
Nick Neid, Project Manager, Ichijo USA
A new age of high performance building has taken place, and zero energy is more possible today than ever. However, homes that are designed and built with aspirations that are too lofty do not always realize their zero energy goals. This session will examine three projects from our region that attempted net-zero energy that now have been lived in for over a year. Find out how each of these projects have been performing and what the key factors are of the projects’ success – or lack thereof. Learn what works, what doesn’t work and what some of the pitfalls are in designing and building innovative high-performance projects.
Hope you can make it to the next B-Green talk I’m organizing. Reserve your tickets here.
When it comes to renovating for energy efficiency, home energy auditors are always stressing the importance of starting with the “low-hanging fruit,” measures like air sealing that are relatively cheap but pay big dividends in energy savings. Equally important is making sure you’re taking advantage of any rebates or incentives available in your area. I wrote a quick roundup of programs in the Seattle area, published in this month’s Natural Awakenings magazine. You might be surprised by how much you can save!
The article starts on p. 23 of the online edition.
Earth Techling and Fine Homebuilding Magazine just published some interesting articles about our house that highlighted the relatively low cost-per-square foot price tag. It’s great to see the idea of affordable net-zero building getting some media attention. Even more gratifying, however, is that I talked to the builder of our house, Ted Clifton of TC Legend Homes, and he says that he gets a call about every week from someone who has heard of our house and is interested in building a zero-energy house of their own.
It’s no wonder people in Seattle and elsewhere are interested in this type of construction, since it represents some serious long-term savings. One commentator on the Fine Homebuilding article wrote:
Of course, for a net zero house any initial savings is really just icing on the cake anyway… Can you imagine the savings that will take place during the life-span of the home? . . . My average cost for gas alone is $1,500/yr. (hot water & furnace), literally burned every year (“litterly” was my Freudian slip). If you include the cost of electricity, then I’m out another $950/yr., for a total expense of $2,450/yr. (gas & electrical alone – my water & sewer are another “drain” altogether :-)
So, every ten years I’m out +/- $24,000, which coincidently adds up to about the same as my 2 latte/day addiction… Maybe that’s the way to market this to the Seattle-area crowd: net-zero = free caffine :-)
Here are the articles . . .
Earth Techling: Attractive Net-Zero-Energy House on a Budget
Fine Homebuilding: Seattle Homeowners Build an Affordable Net-Zero-Energy House
If the average human takes about 20,000 breaths per day, and Alex and I are home about half the day on average, that means we fill our house with about 600,000 exhalations per month. Add those of our new puppy, Beatrice, whose main activity is to sit around and breathe 23 hours a day (and run around like an insane monkey the other hour), and you start to approach a million breaths.
That’s a lot of hot, humid air. Where does it all go?
Researchers from Washington State University have chosen our house for a study that will determine just that.
They’re placing sensors in about fifty Puget Sound houses to monitor key air quality indicators. Their equipment also tracks when ventilation fans are on and when doors are open. The goal is to find out how ventilation works in today’s newer, more airtight homes.
Poor air quality can cause tiredness, the inability to concentrate and make decisions, and even serious illness. Avoiding products that emit harmful pollutants into the air is important, but to ensure that your indoor air quality is healthy, ventilation is required.
What’s Being Tested
Air quality professionals can measure a range of factors, including mold spores and volatile organic compounds (VOCs), but this study focuses on one of the best and simplest indicators: carbon dioxide (CO2).
We exhale CO2 with each breath, and levels rise if ventilation is insufficient. CO2 itself is not toxic, but high concentrations, above about 1,000 parts per million, indicate that a room may be under-ventilated and could be harboring other, more toxic compounds.
Getting Ventilation Right
Testing your air can help you save energy. High levels of CO2 indicate that you may need to increase your ventilation, but unusually low CO2 levels may tell you that you can cut back. Over-ventilating your house can’t harm you, but it may be wasting energy by allowing too much conditioned air to escape, undermining the effects of good insulation and an air-tight building envelope.
I’d love to get a controller for our ventilation fan that turns it on when a certain CO2 level is reached. Unfortunately, the cost is prohibitive.
Representatives from WSU have asked us not to share any results until the study is complete, but that doesn’t stop me from checking the displays on the little meters they’ve placed throughout our home. It’s very interesting to see how CO2 goes up when a door is closed and our ventilation system is turned off (one of the scenarios they’re testing).
What I can say now is that we have a very tight house, and the difference between ventilating and not ventilating is fairly dramatic. One thing is for sure, our houseplants are happy: When CO2 rises, they start growing! In fact, if you ever notice your indoor air feeling a bit stuffy and your plants growing like mad, it may be a sign that you should test your air.
John Brooks, a reader of my recent article in Green Building Advisor asked this:
You posted the Net Energy Balance for 12 months. I am curious how that relates to your actual Energy Bill….the sum of the checks that you write to the “power provider” over 12 months? (Including the base customer charge and difference in buy-back rates)
That’s a good question that others have brought up to us before. The short answer is that during the cold, dark days of our first winter, we paid small electrical bills. In the spring, when the sun came out and our heating needs diminished, we started generating more power than we were using, which showed up as credits on our electric bill.
After about fifteen months of living in the house, we currently have a credit of about $230 on our account. We had the option of requesting a check, but we decided to leave that credit on the books to pay our bills this winter. If our usage is like last year, that $230 credit should more than last us through the winter, so we probably won’t be paying anything out of pocket from now on.
Here’s a breakdown of our last twelve months of bills:
10/28/11 - 1/13/12: $90.01
1/13/12 - 03/14/12: $55.42
3/14/12 - 5/11/12: -$32.25 (credit)
5/11/12 - 7/11/12: -$125.07 (credit)
7/11/12 - 9/11/12: -$92.98 (credit)
9/11/12 - 11/9: -$12.29 (credit)