New PHIUS+ 2015 released and in effect as of March 16th, 2015
jackofalltrades777
| Posted in Green Building Techniques on
Interested to hear comments on the new PHIUS + 2015 that went into effect on March 16, 2015. They made a lot of changes and the biggest being the each climate zone and specific area will have its own standards. Not one big gigantic fits all approach like PassivHaus but very specific to climate zones, house size, etc.
Read more here:
http://www.phius.org/phius-2015-new-passive-building-standard-summary
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Replies
Peter L.,
At first glance, it looks like the new standard hasn't changed since I last reported on it: Redefining Passivhaus.
This new standard faces some challenges. It isn't simple. It requires the services of a consultant to implement. And I'm not sure that it offers a compelling product to home buyers.
Martin,
Do you think the new PHIUS is a bad standard?
Consultants are needed on most energy efficient builds. Some of the GBA experts that post articles here do consultation work and being a consultant is not a bad thing either.
Peter L,
Q. "Do you think the new PHIUS is a bad standard?"
A. I think that the PHIUS standard is better than the Passivhaus standard. However, it isn't easy to implement, and I'm not sure why anyone would want to try to comply with it.
Here's what I wrote in the article I linked to:
"If homeowners choose to follow the PHIUS path, what kind of a house will they end up with? It won't be passive. Like most homes in the U.S., it will require active HVAC equipment to supply space heating, cooling, ventilation, and domestic hot water.
"It won't have the lowest possible ownership cost (that is, mortgage cost plus utility costs), because the PHIUS committee has decided to require investments in envelope measures that push the cost of a new home beyond the cost-optimum point.
"It probably won't be a net-zero-energy house, because the PHIUS committee isn't considering a requirement for a PV array that can balance annual energy use.
"Time will tell whether there is much of a market for this type of home in the U.S."
Q. "Consultants are needed on most energy efficient builds. Some of the GBA experts that post articles here do consultation work and being a consultant is not a bad thing either."
A. I agree. I often recommend that GBA readers with tough questions hire an energy consultant. However, a PHIUS house is going to require more money for consulting and certification than most Americans are willing to spend. I'm not convinced that it's the best use of their money.
Martin, you stated:
" I think that the PHIUS standard is better than the Passivhaus standard. However, it isn't easy to implement, and I'm not sure why anyone would want to try to comply with it."
Nothing above code minimum is easy to implement and contractors don't want to even comply with code minimum. It will come down to the home buyer/owner.
You stated:
"If homeowners choose to follow the PHIUS path, what kind of a house will they end up with? It won't be passive. Like most homes in the U.S., it will require active HVAC equipment to supply space heating, cooling, ventilation, and domestic hot water."
Even a Net Zero home requires heating, cooling, ventilation and domestic hot water. Unless someone is living in a cave the requirements mentioned above are crucial to any modern day human habitation.
You stated:
"It won't have the lowest possible ownership cost (that is, mortgage cost plus utility costs), because the PHIUS committee has decided to require investments in envelope measures that push the cost of a new home beyond the cost-optimum point."
The lowest cost of ownership is not to build or to buy a home, it's to rent a small apartment. Most people want to own a home and what the PH offers is a home that is much more energy efficient than a standard code home and the cost of ownership is in the long term where the home itself can be heated/cooled with very little utility requirement.
You stated:
"It probably won't be a net-zero-energy house, because the PHIUS committee isn't considering a requirement for a PV array that can balance annual energy use."
That is NOT correct. The new 2015 PHIUS standard allows one to offset primary energy use from PV. An estimate of coincident production-and-use of energy from renewable energy systems (such as PV) will be allowed to be included in the calculation. (See POINT4 - PAGE#2 of the PDF showing the new changes.)
In addition, the U.S DOE & Building Science Corporation stated that the best way to achieve Net Zero is to use the Passive House approach.
Peter,
Just because the Building Science Corporation (a for-profit company that received a DOE contract to write a report) said that "the best way to achieve Net Zero is to use the Passive House approach" does not make it true. I respectfully disagree.
Moreover, just because that statement appeared in the BSC report does not mean that it represents official DOE policy.
I stand by my statement that a PHIUS-certified house "probably won't be a net-zero energy house." While the new PHIUS standard provides credit for some (but not all) of the electrical output of a PV array, it does not require homes to include any PV (as my article explained). Time will tell whether my prediction is correct.
You wrote that "the lowest cost of ownership is not to build or to buy a home, it's to rent a small apartment."
While you are twisting the definition of "ownership," I understand your point -- and I agree. In general, renting a small apartment is a much more environmentally friendly approach than building a new house.
Peter L wrote:
"Nothing above code minimum is easy to implement and contractors don't want to even comply with code minimum."
It gets a bit annoying to constantly have certain segments of the industry tarred with such broad brush attacks. Which contractors don't want to follow the code? All of them? Bad ones? The ones around where you live?
Malcolm,
Q. "Which contractors don't want to follow the code? All of them?"
A. Almost all of them want to -- but most don't really know about important code provisions, and many important code provisions aren't enforced.
Here are a few rarely enforced code provisions:
1. The requirement that HVAC contactors size heating and cooling equipment according to a Manual J calculation (or an approved equivalent method).
2. The requirement that fiberglass batts be installed according to manufacturers' instructions.
3. The long-standing code provisions that duct systems must be "substantially airtight."
4. The code provision (dating back to 2006 or earlier) that “the building thermal envelope shall be durably sealed to limit infiltration.”
Malcolm,
I don't create the perception and attitude of the general contractors out there. They have created the image and reputation themselves. Studies and polls have shown that people in general DO NOT trust contractors and that contractors have and will cut corners whenever possible. There are exceptions to that rule but the majority have set the tone.
In my field of work I deal with a lot of contractors and if given the chance to save $$ by either reducing & eliminating insulation OR reducing & eliminating granite countertops, the majority of them will reduce or eliminate the insulation. Why? It's simple. Insulation does NOT sell homes but granite tops do. Insulation is hidden from view between the sheetrock and exterior wall, nobody sees it.
If it wasn't for codes and code inspections, there would be many homes with missing insulation and poorly detailed wall/window/roof details. 95% of homes being built today are CODE MINIMUM yet those same homes will have granite tops and other aesthetic upgrades.
In my area when the 2012 IRC and 2012 IECC codes were being discussed and implemented the BIGGEST complainers for implementing the 2012 IECC were CONTRACTORS. Surprise surprise! They moaned, groaned, snarled and threatened the board of supervisors. Long story short. The board decided NOT to implement the 2012 IECC but to keep the 2006 IECC. They did adopt the 2012 IRC but because of the pushback from contractors the 2012 energy codes were thrown into the trash. So as I type this thousands of homes are being built to energy codes developed 10 years ago. Hello R-13 fiberglass wall batts and R-30 batt roofs, here we come!
Peter, that's a bad situation. Perhaps I'm sheltered a bit by local conditions. Most contractors here do build to what you call "code minimum", but our code is very progressive and generally well enforced, so you end up with a very good house. Looking at the houses being built now in our region, compared to those of twenty, ten or even five years ago, the changes are startling. Hopefully things improve where you are too.