In an overflowing conference room in the Boston World Trade Center, Michael Blasnik, the well known residential energy analyst whose SIMPLE model powers EAI’s Energy Performance Score (EPS) SoftwarePlatform, held a session titled “Energy Modeling: Stop Wasting Your Time!” In this session, Mr. Blasnik discussed numerous studies (including EAI’s 2008 Pilot Report) which show that highly detailed energy models tend to be very inaccurate and inconsistent compared to actual utility bill data. He discussed how the SIMPLE methodology he created is much more consistent to actual utility bill data. He proclaimed, “It is better to be approximately right, than precisely wrong.” In a separate thread, Mr. Blasnik discussed how the BESTEST standard is inherently flawed and to pass the test, a software modeling tool has to be compared to dated software programs (DOE2, etc.), rather than accuracy to actual utility bill data.

Another highlight of the conference was the session titled “Finding the Right MPG for Existing Homes.” This session was moderated by Nancy Hazard, of World Sustain and featured Ian Finlayson, of the MA Department of Energy Resoures and Kevin Galligan, of Cape Light Compact. Mr. Finlayson was representing the Mass Save pilot program that features the EPS Software Platform & EPS Scorecard. Mr. Galligan was representing the Cape Light Compact pilot program that featured the Department of Energy’s Home Energy Score (HES). Based on the reception of the large audience, there was generally excitement for the easy-to-understand EPS. One audience member raised his hand and proclaimed to the crowd, “I have to say, I really like the EPS Scorecard!” The big takeaway from this session was that the EPS and the HES are truly complementary scores. Similar to the most recent MPG label for automobiles, the EPS equates to the ‘MPG’ for a home and the HES is a 1-10 scale, providing the homeowner context on how efficient their home is. Furthermore, the audience generally held that the EPS and HES labels are more consumer-friendly and cost-effective than the HERS Index, a metric used primarily for new home code compliance.

My house is smallish at 1775 sq. ft. but easily large enough for a family of four. It was built in 2004 by Sunterra Homes for about $260,000, and this price was average for all the houses in my neighborhood. The house was certified Earth Advantage Platinum with features including, passive solar heating, Forest Stewardship Council (FSC) lumber, zero-VOC paint, hydronically-heated concrete floors, solar water heating, photovoltaics and much more. (Full details on the house can be seen HERE.)

When setting the price, I worked with Earth Advantage Brokers Jason Boone and Terry Skjersaa. They investigated recent sales in the neighborhood and reported prices ranging from $95 to $100 per sq. ft.— establishing the market value at $177,500.

To estimate the value of the green elements, I used the Appraisal Addendum created by EAI last year. This form allows home sellers to list green features and assign a dollar value to each one. I used the installed cost, and the green features in my home totaled $46,000. Added to the base value of $177,500, the $46,000 in green features established an upper limit of $223,500.

Home prices in Bend are now at their lowest level since housing bubble burst. Realistically, I didn’t expect to receive the full value after the Energy Addendum addition, so on the advice from my brokers, we set the price at $209,000— $31,500 higher than the established market price.

We brainstormed ideas for maximizing the green message, and the plan included these elements: 

• Asking that a buyer’s brokers contact the listing brokers before showing the house. This gives the listing broker a chance to tell the green story.
• Putting together a detailed binder with the full list of green feature, as well as usage records for electricity, natural gas and water.
• Holding a brokers open house at which I would be present to explain the green elements. (Having a seller present at an open house is highly irregular, but seemed appropriate in this case.) 
• Placing collateral throughout the house to explain specific green elements, especially those that aren’t visible. 

Finally, we had to keep in mind that green was far from the only selling feature. In fact, location, amenities and comfort were really the principal selling messages. We were prepared to address those topics first and then bring the green messaging into the mix to close the sale.

The house was posted on Wednesday morning, and at about 9 p.m. that evening, I heard that a full-price offer was in the works. I happy to report the sale is officially closed and the process is complete.

Several studies by EAI and others have shown the additional market value of green homes, and my experience is a direct testimonial to this data. In a down market, my house received a higher price and sold faster than any home in the neighborhood. It’s one example that you can capture the green premium when you are supported by a talented group that includes a thoughtful builder, an effective sales team and Earth Advantage Institute.

Image Courtesy of Bryan Hilts, Cloudnine Photography 

All of the homes in this series have some pretty neat sustainability features. The cabinetry in this home was milled from a white oak tree that fell in the homeowners' previous lot. Talk about resourcefulness! Click here to view the full case study.

However, this home is designed and engineered to be ultra-efficient and extremely healthy. Read and share the full case study and watch for #3 in the series, coming early next week. 

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.