Starting with this post and the 5th Highest Scoring EA Home, stay tuned over the next few weeks for the case studies about projects #4 - #1.

The Energy Trust report analyzes energy performance scores that are“ asset‐based”, meaning a scoring system that removes occupant behavior and considers only the home’s physical structure, the applicable climate, and a standard set of operating parameters (e.g., thermostat settings). A useful analogy to an asset-based home energy score is the Miles per Gallon (MPG) rating on a new car. MPG ratings for cars are determined using a set of controlled conditions. While individual car owners’ actual driving behavior and circumstances rarely match these conditions exactly, the rating allows buyers to compare cars. Homes, of course, are more complicated than cars; they differ substantially in vintage, square footage, climate, heating systems, architecture, and fuel types. However, based in part on Earth Advantage’s work, the country is inching closer to a scoring system that would have broad applicability and allow for true comparisons between homes.

For several years, companies and organizations nationally (including Earth Advantage and the US Department of Energy) have been developing and pilot-testing asset-based modeling tools. The concept is that a simple, consistent, and reasonably accurate home energy scores will tell homeowners and buyers how their existing or prospective home performs relative to others, and that this information will motivate them to make decisions regarding efficiency improvements and purchases that result in broad energy savings.

Because of the region’s status as an energy policy leader and the strong movement toward asset-based energy performance scoring tools, the results of the Energy Trust study have truly national implications. It is extremely gratifying to see Earth Advantage’s hard work supported in the results of the study. Energy Performance Score Modeling Comparison (from Energy Trust’s analytical report): 

1. Urban Density

Filling in the spaces is the name of the game as homeowners and builders opt to create more living space through the construction of accessory dwelling units (ADUs), laneway homes (bordering the back lane behind the main house), and build on infill lots. All this because the younger crowd and the empty nesters are opting to settle in the city where they can be closer to cultural activity, mass transit, more sustainable lifestyles, and other like-minded people.

2. Green Multifamily Homes

As a corollary to the urban density trend, Earth Advantage Institute has seen a large spike in Northwest multifamily building certifications this past year. The increased interest by building owners and operators in energy efficiency savings coupled with 2011’s 17% growth in multifamily homes (McGraw-Hill) means that we can expect to see a rise in certifications in this sector, especially in progressive regions.


3. Energy Upgrades Start to Drive Home Remodels 

Builders and remodelers who are plugged into changing consumer preferences (smaller homes, reduced energy bills) have been able to capitalize on energy upgrade work. They have moved into the energy audit and residential retrofit market by either expanding their service offerings or, in the case of large West Coast remodeler Neil Kelly, creating entirely new service groups. In the Northwest, demand has increased, leading to significant new energy improvement business for these firms. Remodelers see such work as a driver to help bring in more remodel leads.

4. Deployment and Testing of New Materials

Although architects and builders are eager to try to new energy-saving materials and systems, these products require significant testing to ensure that the materials and benefits will last the life of the building and to avoid litigation. As a result, national labs and university research departments are partnering with builders to create test beds and sensor-filled buildings that log the energy performance of new materials and equipment. Portland State University’s mechanical engineering department recently partnered with a local builder to measure the effects of phase change material used as insulation in a duplex passive house, while Lawrence Berkeley National Laboratories is constructing a test bed that will track all performance aspects of new materials and equipment.

5. Consumer Friendly Home Energy Tracking Devices

The introduction of the Apple-like Nest Learning Thermostat, and Belkin’s Conserve Insight energy use monitor that tracks energy use by appliance, are two of many sensor-based energy and water monitoring products for the home that are easy to use and help save money. Large electronics players like Fujitsu and Intel are also developing products, among others.

6. Energy Education for Commercial Tenants

The growing adoption of commercial building energy disclosure (New York, Washington, D.C., San Francisco, Seattle, Austin) has building owners/operators and utilities seeking effective ways to educate tenants on saving energy. Technology can only go so far in conserving energy without tenant participation.

7. Transparency in Home Marketing

The increasing use of smart devices by consumers to instantly access information at a home site means that buyers are much more informed and can see through any greenwashing claims. Those builders, remodelers, and real estate professionals who can clearly educate their clients about the benefits and features of energy efficient, green homes will be those who earn the buyers’ confidence.

8. More Accurate Appraisals

The old-school appraisal criteria based on a drive-by look at a home – view, approximate square footage – no longer holds. The ability for sellers and buyers to ask their banks for a green-certified appraiser (Certified Residential Green Appraiser) means that the lending community will buy into the idea of the additional value and return on investment offered by new certified homes and remodels.

9. Broader Adoption of Residential Energy Ratings for Homes

Energy labeling systems are appearing in many states, offering a miles-per-gallon style estimate of a home’s energy consumption for homebuyers and homeowners. The Energy Performance Score and the Department of Energy’s own Home Energy Score have been rolled out in different climate zones across the US to encourage homeowners to compare energy use and undertake energy upgrade work.

10. Smart Grid-Compatible High-Performance Homes

According to Smart Grid News, household appliances (heating and cooling systems, refrigerators, electronics, hair dryers) account for 60 to 90 percent of the residential electricity consumption in the U.S., depending on whose reports you read. Increasing numbers of those appliances are becoming “grid-aware” and are gaining the ability to monitor and report their own usage and to increase or decrease their electricity usage by remote command.

Most people probably have electric dryers in their homes. However, if your home uses gas in any capacity and you would like to convert to a gas-operated dryer, a professionally licensed HVAC contractor can easily run a gas line to your laundry room. A gas dryer costs about $50 dollars more than its electrical equivalent, but they cost much less to operate. An average dryer has a life span of about 15 to 18 years. Depending on where you live and the local utility rates, it could cost anywhere between $1200 - $1800 dollars to run your dryer over its lifespan. Electric dryers don't cost much to operate, about $0.30 to $0.40 cents per load. Gas costs about half of that, roughly $0.15 to $0.20 cents per load. Add this savings up over the lifetime of your dryer and you will be saving enough money to probably pay for the equipment itself!

And if that wasn't enough knowledge for you, here is that interesting tid-bit I promised you: Gas dryers do not create an electrical static charge, and therefore eliminate the need for static cling sheets. Of course, the best method of drying laundry is to use nature's own dryer: the sun and the wind. Sunshine can be a rare comodity here in the Northwest, so drying your clothes outside during the wet winter months isn't always the most practical option either. 

How Do We Test It: Explaining the Numbers

For this explanation, I would like to point readers to the good people over at the Energy Conservatory. Here's what they have to say.

Next steps: Ventilation ‘Build Tight – Ventilate Right’

It is unwise to rely on air leakage for ventilation, because it’s unpredictable and can't be controlled. The source of the infiltrating air is unpredictable— potentially coming from the crawlspace, garage or attic. Thus, controlled ventilation is the answer to ensure that properly sealed homes are also healthy. The national standard for ventilation is ASHRAE 62.2. This standard ensures that enough fresh air is provided to the home determined by the size of the home as well as number of occupants. The ASHRAE 62.2 calculation is as follows: (7.5 x (# of Bedrooms + 1)) + (0.01 x conditioned floor area) = Total Cubic Feet per minute (CFM) required. Click here for more about ASHRAE ventilation standards. 

Indoor Air Quality (IAQ): Avoidance, Ventilate, Filter

Indoor air quality is one of the cornerstones of green building.  A tight, well-ventilated home is the first step to creating a healthy indoor environment.

What is the difference between air tightness, air infiltration, & air leakage?

 All buildings have to be ventilated for health and comfort and airtight buildings are no different. Airtightness is achieved through careful implementation of strategy throughout the design and construction phases.

Air leakage is the undesired and uncontrolled movement of air in to and out of a building which is not for the specific and planned purpose of exhausting stale air or bringing in fresh air.  Air leakage is called “infiltration” (air moving into a building) or “exfiltration” (air moving out of a building).  

Why is air tightness important? 
Air leakage is a major cause of energy loss.  Typically between 30% - 50% of heat loss can be attributed to air leakage.  Air leakage has also been shown to reduce the effectiveness of thermal insulation by up to 70% and so it is clear that energy efficiency is greatly affected and influenced by airtightness.

Air leakage can also lead to other building and comfort problems such as drafts, frozen pipes, ice damming, moisture movement (creating mold and compromised air quality), and ultimately building failure due to rot and decay. 

Different weather conditions affect air leakage as well, with heat, cold, or windy conditions leading to more infiltration.  Air infiltration also can contribute to problems with moisture control.  Warm moist air leaking out of a home may meet with cold surfaces causing condensation, which could then lead to moisture in walls and other undesired places.  Moldy and dusty air can enter into a leaky home as well.    

How is air tightness accomplished? 
Prevention is cheaper and easier than cure.  The recommended strategy in both new and old homes is to reduce air leakage as much as possible and to provide controlled ventilation as needed.  Properly air sealing cracks and openings in your home can significantly reduce heating and cooling costs, improve building durability, and create a healthier indoor environment.  Many holes connect the various components of a building; i.e. plumbing, electrical and HVAC holes through walls floors and ceilings, connecting crawlspaces to main living areas, garages to main living areas, and main living areas to un-conditioned attic spaces.  All of these connections contribute to compromised air tightness.  Properly addressing these areas and air sealing where appropriate could save hundreds of dollars in heating and cooling down the road as well as create a more durable home.     

The instructor mentioned that every time we use more energy than needed, we're putting extra carbon in the air. Now, I know this is a pretty basic fact. Extra carbon contributes to global warming and pollution. Energy from non-renewable sources that I use now is energy not available for future generations. 

However, on a practical level, I really never used this as criteria for saving energy. Generally, I would think, "Well, I'm willing to spend a little extra money, because I want to turn the heat up a bit or I need a longer shower," or, "Surely, this little bit of energy I'm using won't make that much of a difference in the overall scheme of things." Evidently something about this simple statement worked its way deeper into my consciousness.

I have four grandchildren, and I hope someday to have a couple more. (Unfortunately, unlike turning an electric switch on or off, this is out of my control!) What I can control is my energy decisions, and my grandchildren's well-being is now the determining factor in these. I can't justify jeopardizing my grandchildren's future by dumping extra carbon into the atmosphere for a little extra heat or a longer shower. I've read things like "you need to hear something seven times before you remember it" or "if you do something for three weeks, it becomes a habit." I don't know if those things are true, but I do know that I've changed the way I look at using energy.

It’s no secret that Portland is a hub for sustainability, energy efficiency, and environmental concerns. The City of Portland has had an active role in urban planning. Some of the results have been the preservation of city parks, a comprehensive strategy to reduce carbon dioxide emissions, and the establishment of lower-impact mass transit, including a light rail and dedicated bike lanes. This type of infrastructure has created a slew of startup organizations and nonprofits that focus on green and environmental issues. Earth Advantage, for example, just happens to be one of the early adopters of Portland’s green scene. The organization began as a resource to influence energy efficiency and sustainability in residential new construction, but has since diversified into many other areas that deal with sustainability and energy efficiency in the built environment.

Additionally, international green companies call Portland their North American home, such as Solar World (Germany) and Vestas (Denmark). These companies see Portland as having the right kind of people to help establish their products in the marketplace, as well as a city, that is welcoming to their technologies.

Metro is a unique local organization that works in the three counties comprising the Portland Metro area. The organization has helped both businesses and residences make a difference and reduce their environmental impact by coordinating low-impact development practices during construction, natural gardening classes, walking/biking programs, and comprehensive recycling programs. One of Metro’s programs recycles virtually every type, color, and manufacturer of paint and creates a “new”, low volatile organic compound (VOC), Green Seal Certified paint that can be used internally or externally on homes and buildings.

Portland has also seen a huge increase in the number of new restaurants and over the past few years that focus on “farm to fork”, local, and/or organic offerings. Portland has not only become a hot bed for great gastronomical delights, but a place where young creative chefs are migrating to make their mark on the culinary world. Portland boasts almost 700 food carts in the city. 700! And many of these are offering natural, organic, and local ingredients that makes one ponder, “Why would I ever eat at fast food restaurant again?!”

From Portland’s numerous festivals (i.e. Rose Festival) to the many breweries (i.e. Hopworks Urban Brewing), wineries (i.e. Sokol Blosser), distilleries (i.e. New Deal), coffee roasters (i.e. Stumptown) and offbeat places to visit (i.e. Voodoo Doughnut), it’s important to keep in mind that rain isn’t the only thing that helps make Portland such a green city. The underlying vibe and community emphasis towards a lower-impact lifestyle help make Portland one of the greenest cities in the country, but also a place that truly emphasizes the “Earth” in Earth Advantage.

Ella Wong wrote in to update us on the status of her net-zero, passive house, duplex "Trek Haus" being built in southeast Portland by architect/contractor Robert Hawthorne and builder Bart Bergquist. KATU-TV just aired a segment on Tuesday featuring the Portland State University mechanical engineering students who are studying the phase change insulation material being tested in one of the units (the other is the control unit that uses more standard insulation).

The phase change material, called BioPCM, is an innovative soy-based phase change material that reduces energy usage and improves thermal comfort.  It adds thermal mass and is easily installed (like insulation) in walls, ceilings, floors, and attics of new builds as well as retrofits. It looks sort of like large bubble wrap or foil pill container sheets --- except that the pockets are filled with the soy-based material that absorbs heat when it melts in warmer weather, and that releases heat when it solidifies in cooler weather. Both units of the duplex have been wired with sensors that feed into data loggers, with the goal of one year of monitoring. Collected data will include indoor air and wall temperature, humidity, moisture, CO2, heat flux in the exposed slab, site weather, sub-metered electricity use for all major circuits, window usage, and air infiltration.

Recently, I conducted a blower door test on a house to measure the air leakage. The builder used a spray foam product to fill the entire floor, wall, and ceiling cavities. My initial thought was that this is going to be a very air-tight house. After testing, the results were good, but not as great as I had envisioned. 

Spray foam is a product that when installed correctly has the potential to save a lot of energy, but the inefficiency of the product lies in the small details of installation. The installers must be conscious of air infiltration. With the use of an infrared (IR) camera, the locations of air leaks were easy to find. The floor-to-wall connection, ceiling-to-wall connection, and the structural beams penetrating the exterior wall were the main leaky spots. Unfortunately, the house was finished and sealing the vulnerable areas now would be a difficult and costly endeavor. 

Many builders have achieved phenomenally tight houses without the use of spray foam, including two recent Central Oregon net zero homes! This level of building performance requires an extremely good eye for detail and a dedicated team of sub-contractors. In the end, it doesn’t matter what product is used when air sealing and insulating a house. All that matters is the correct installation and attention to detail.