Image Credit: Marc Rosenbaum
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The Town of West Tisbury passed the Stretch Code at Town Meeting this year. It’s a more stringent building code and in essence it speeds up the adoption of the next iteration of the International Energy Code.
Debate was spirited. “Aginners” (as in, “I’m agin’ it”) made impassioned pleas about how it was just another gubmint-imposed tax on those that could least afford it, the working folks. My opinion is exactly the opposite: Martha’s Vineyard’s tax on the working people is $4+ per gallon oil and propane, and almost $0.20/kWh electricity. A tougher energy code is the worker’s friend in the long run.
These days, Habitat for Humanity is an efficiency pioneer
Next to those designed and built by South Mountain Company, the most energy-efficient houses on Martha’s Vineyard are being built by Habitat for Humanity. They are dedicated to permanent affordability for their owners.
In the past, Habitat for Humanity often was the recipient of donated products that were sometimes on the low end of energy efficiency, such as inexpensive windows and low efficiency heating and hot water equipment. On Martha’s Vineyard, the forward-thinking folks who operate Habitat for Humanity are, with some detailing help from South Mountain Company, building superinsulated homes that are very airtight. I help with quality assurance (QA), testing the houses with a blower door and a fog machine or IR camera.
Exterior polyiso foam and ductless minisplits
The first house at Bailey Park Road had a tested air leakage rate of 175 cfm50 at the stage of windows and doors installed and most of the rough-in done, but no drywall. In the next month they’ll be ready for a final test.
Recently we tested the shell at the second house they are building there, with window and door openings poly’d off. It was just about 300 cfm50 with the air barrier being one layer of taped polyiso foam on the walls and roofs. The house is a kit, which is all tongue-and-groove pine inside — a potentially very leaky strategy.
With volunteer workers, they’re building a house tighter than almost all the pros do here. The beneficiaries will be the owners. The mechanical system is minisplit heat pumps, far less costly to operate than fossil fuel equipment. Thanks, Habitat, for leading the way to permanently affordable housing.
Marc Rosenbaum is director of engineering at South Mountain Company on the island of Martha’s Vineyard in Massachusetts. He writes a blog called Thriving on Low Carbon.
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13 Comments
3-D network of Voids
Marc, Is the Polyiso "THE" one & only air barrier in the Second HforH house?
If so ... isn't it risky because of the 3-D convection network coupled to the interior space ...that Joe writes about in Insight-036 ?
http://www.buildingscience.com/documents/insights/bsi-036-complex-three-dimensional-air-flow-networks/files/BSI-036_Complex_3D_Airflow_Networks.pdf
From BSI-036: "The convection loop in this example is not catastrophic because it is not coupled to the interior space – note the air barrier sheet membrane under the rigid insulation. Had the air barrier not been present the convection cells would have been coupled to the interior and there could have been moisture transport from the interior into the roof assembly. With moisture transport from the interior the roof would have likely been doomed as it is located in a cold climate"
What does the tough energy
What does the tough energy code call for that people are objecting to?
Gee, Ron,....
I've typically found that ANY requirements are seen as a government imposition, that "all we need to do is let the free market work".
That said, I've certainly seen code require things that are not needed or are even damaging: like interior polyethylene in cold climates with exterior foam.
Good Candidate for PV
Long term affordability is the #1 goal of H4H, and this house is a good example.
That should not be the goal of the building department. Minimum quality and safety standards is their mandate. The technology of energy efficient, comfortable housing is still changing too much to codify it.
To require R48 walls (just for example) would be beyond their mandate because other technologies like PV (just for example) may be more cost-effective.
Expanding the Mission of the Code
Dustin,
I don't think many people object to the code mandating standards for structural safety. That does not sound like what the people were objecting to in West Tisbury.
Workers Best Friend
I wonder if the house were being built "at market rate" , say by a private builder for profit if the "pruchaser or end user" would agree that the energy saved would be positive ROI. Sitting here in SC it is hard to understand the economics of Cape Cod climate but seems like extra cost went into the house. Understand I am only using the data in the article. I support energy savings but somebody pays the bill. THanks Lou Gage
How many people look at the ROI on energy efficiency?
The free market approach of letting people calculate the ROI of efficiency improvements sounds great in theory. I think most people buy houses with their hearts -- the beautiful kitchen with granite counters, the spacious master bath, or the third extra bedroom. Then they decide (or the bank decides) if they can afford the mortgage payments. If they think about it all, the utility payments are way down on the list.
Part of this may be that the utility cost numbers are not readily available. Buy a new car and the estimated mileage is on the window sticker. You want to by a used car, the same info is available on the EPA website. Even then, I bet many people ignore this info or don't trust it. Houses seldom have this type of information available and if it is, its accuracy is even more suspect. If nothing else, occupant behavior is so widely variable.
Minimum energy standards in the building codes will, if well designed, reduce the energy costs and help our planet over the 100 year life of the house.
ROI
Some people might not have the extra money to spend upfront for a return as energy savings over time; or they may have the money, but prefer to save the upfront extra cost in favor or buying more energy over time.
I have built a house that far exceeds the typical energy efficiency. If I build another one, I will go even further with upfront investment in high performance. But I would not want to see everyone forced to do the same if they decide to build a house.
Once you start expanding the mission of the building code, it strikes me as an incredibly slippery slope. And I would expect that the more complex the regulations become, the more the permitting and inspection costs will increase.
No one is talking about mandating higher costs
Ron,
I don't believe there is any suggestion in the code or by you that we have uneconomical improvements in efficiency. Therefore, the new code will lead to owners having a smaller total out-of-pocket (mortgage + HVAC) for your new efficient homes each and every month they own one. Who can argue?
1) Owner gets smaller total costs and more comfortable home.
2) The world gets smaller CO2 and other externalized costs.
3) The contractor, freed of the need to compete against the slightly cheaper inefficient homes can build homes of which he is proud and still recoup his costs.
4) The community get slightly higher property values.
I can't see any losers.
Is there any way in which this is not a winner?
Aha
Dustin,
Your post contains the basis for a performance based code: "new code will lead to owners having a smaller total out-of-pocket (mortgage + HVAC)". That's the real goal here, not some arbitrary set of R values and air tightness measurement or what kind of light bulbs to use.
Everybody loses when the prescriptive codes become obsolete compared to the available technology.
What if Passive House guidelines were adopted as code? It has been proven over and over that net zero can be achieved with PV and pretty good insulation specs at a much lower cost.
Although I really like your reason #4, it's too early in the game to force everyone into a set of specifications that are more costly than other methods. Another reason to wait is that some unintended consequences of these new mandated specifications have yet to manifest themselves.
A Worker's Friend...
Dustin,
It is indeed a mandated cost increase upfront. You can argue that over time the upfront investment gets paid back in lower energy costs, and eventually even returns a profit. But there is a cost to tying up money over time, and there is also a risk. The cost is the interest that the money could earn. The risk is that investor will not be in the house long enough to reap the payback.
So not everybody is going to be convinced that they are better off spending more money upfront because they will get it back in the long run. Not everybody has the wherewithal to invest in something just because it returns a profit. People have to live within their means no matter what investment opportunities present themselves. Furthermore, a lot of people simply will not believe the promise of a payback on the energy enhancements, so they will resist the mandatory investment on that basis.
Some people may plan on only being in the house for say five years. So the only way they can recoup the upfront added cost for the new code is to include it in their selling price. However, we have been told here that lenders and appraisers refuse to account for the value of added energy upgrades because the market does not value these upgrades. So the five year seller will have to eat the upfront costs.
I am not sure what all is meant by the stretch code being the “worker’s friend,” but you say that it will help building contractors. Will it really? Anyone who does not want to pay for the upfront cost of the stretch code energy add-ons may choose to build in a different location that does not have such a code-imposed extra cost.
Ron, you have some points. And Kevin's final point...
You are right about possible problems:
1) If lenders do not value a house right, the owner must carry the extra cost and assume risk that next owner may not be willing to take that extra cost. Still, if all houses in that area are built to the new code, the market will float to the new normal.
2) What if the cost of energy drops? Given the sudden flood of gas we've had recently and the oil we expect from fracking, this may happen and would make some improvements uneconomical. (please don't start about climate change as this is not something that will affect short term costs for homeowners)
"Another reason to wait is that some unintended consequences of these new mandated specifications have yet to manifest themselves."
3) so many building technologies have unintended consequences that it would be unwise to count on new building systems....especially give the interesting ways design, construction, remodel, climate, and inhabitants interact. Maybe we should be going with PERSIST all the way...
Come on man....
I think the point is being missed. To review, the Stretch Code in Massachusetts is a part of what is called the Green Communities Act which provides incentives to conserve energy and fund renewable energy in communities that choose to adopt the act. It is voluntary and, to date, 110 of the 351 cities and towns have joined. The Stretch Code is a perquisite to becoming a Green Community. Essentially, the Stretch Code pushes the 2009 IECC toward the 2012 IECC. In some ways it simplifies the procedure for complying with the code though there have been some issues with the way it was written. The 2012 IECC goes beyond the Stretch Code....there is still no consensus on whether the Stretch Code will continue once 2012 IECC takes effect in 2013. More info on the current stretch code can be found at http://www.mass.gov/eopss/consumer-prot-and-bus-lic/license-type/csl/stretch-energy-code-information.html
It seems the conversation always gets reduced to payback. The energy code is not about payback, it is about building comfortable, efficient, healthy, durable structures. There are other aspects of the building code that add cost to construction. I never hear conversations about payback when discussing these items. For example, the electrical code now requires arc fault and tamper proof devices in every room other than baths and kitchens which require GFCI devices. Code in Massachusetts requires smoke detectors in every bedroom and hallway. And soon may require sprinkler systems in all new construction. There are structural requirements as well that add cost. Everything adds cost to the basic house than was built 100 years ago. Either we have a code to build durable structures to last 100 years or we wing it based on the free market. We will then get the cheap crap the was built in the 60’s, 70’s and 80’s which are doomed to be torn down prematurely because they are failed and defective structures.
Hopefully, the next generation of builders will be on board with the new building science that we are working so hard to bring to the mainstream and will soon be the norm.
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