All building science

School Is In Session! Roll call: Homeowner? Homeowner?

Thursday, February 6th, 2014

Quite often I step backward and look outside the badge of a BPI auditor and put myself in the shoes of a homeowner.  A homeowner whose home I’m about to pick apart.  For the most part homeowners are happy to have us there.  We’re there to help, not to sell. They expect us to make recommendations telling them what should be improved.  They expect, “Fix or replace this, and your house will be better.” What they don’t expect is the education that comes with it.  With an understanding of how these recommendations make a difference, homeowners could save thousands.P1200084

On a recent assessment of a home I was told the main interest in having an audit was to confirm the need to replace an induced draft furnace with a sealed combustion furnace.  The homeowner was replacing a sensor that was failing every few months.  An HVAC contractor suggested buying a sealed combustion furnace.  Ta Da!  Problem fixed.  Not so fast.

It should be noted that the furnace was located in the crawl space; and a vented crawl space to boot.  This was a big factor in several issues, one of which was the routine replacement of the sensor, the comfort in the rooms above the crawl space and poor indoor air quality.  The thinking was that the sealed combustion furnace would reduce or eliminate the likelihood that the sensor would need to be replaced often and that the air flow would be better to the rooms above, increasing comfort.

As you know, a new furnace doesn’t address the root of the problem.  This is where educating the homeowner is valuable.  We need to make sure they understand why we recommend the improvements we do.  We sat down to discuss why the problems existed in the first place and how a new furnace will still leave them with their current problem.

First, let’s look at the sensor problem. The dry, dry dirt in the crawl space was being pulled into the furnace housing and collecting on the sensor.  What he needs is to install a sealed barrier over the ground of the crawl space, preventing premature failure of the furnace.  More importantly, this would improve indoor air quality.  Next was to address the comfort issue in the floor above the crawl space.  With a new furnace and increased air flow to rooms, the vented crawl space would still allow cool air to directly impact the floor above.  To truly fix this would be to seal the crawl space vents, air seal and insulate the rim joist and insulate the walls.  This was an easier fix and less expensive than replacing the furnace.  The homeowner understood and agreed, then decided to pursue improving the crawl space.

In the end, recommendations for improvements are a lot more beneficial if the homeowner has basic understanding of the science behind those recommendations. Too bad there is not a Cliffs Notes of basic building science for homeowners.

Brad Smith
EnergyLogic Auditor

Ventilation Old School Style

Tuesday, July 9th, 2013

Steve Byers and his family are on vacation in Turkey this month. While traveling he is continually reminded of the fact that building science is, to quote the 1980′s British band James, “…like a disease without any cure.” In other words, no matter where you go, building science goes with you.

Direnkuyu is a town in the Cappadocia region of Turkey. In Direnkuyu, there is an underground city, one of some at least forty such troglodyte habitations in the area (so psyched that I am able to use the word “troglodyte” in a post!). These cities were built as refuges for sheltering from attackers across the centuries. To give you a sense of scale, these are not holes in the ground, these are truly cities. The Direnkuyu city could house 20,000 people and their associated livestock. It extended 60 meters underground and had a tunnel connecting it to a nearby city in another village that ran for 8 kilometers. I was fascinated by the entire thing. I banged my noodle about six different times on the ceilings of tunnels out of shear excitement about what lay around the next corner…

In case you think concern about ventilation is a modern development, check this out:  The city had ventilation shafts that ran the entire depth of the structure. The hundreds of family caves were all connected via small tunnels to the main tunnel so that each was ventilated. All cooking was done on the upper level to keep smoke from inhabitants.

One additional function of all these shafts was to enable easy and instant communication around the community. Apparently an even softly spoken, “Help, we’re under attack!” would carry to every level of the complex allowing large circular stone doors to be rolled into place sealing the structure off to invaders. Learning this, we made an immediate connection to our EnergyLogic training center where we have a Duct Music Aire. Never heard of that? Well, the Duct Music Aire was a speaker you installed into your duct system to pipe stereo (quadrophic possibly?) sound around your home. My guess is it worked less well than Direnkuyu’s ventilation shafts.

Which, by the way, don’t leak at all…

Steve Byers
CEO of EnergyLogic, Inc.
RESNET HERS Provider and Trainer – EnergyLogic Academy,5193923


Who Stash Is That? Updated…

Tuesday, April 23rd, 2013

How does one celebrate the Mustaches of Building Science?

Well, we’re not really sure, so we made something up.

In preparation for ACI next week, and a late celebration of International Mustache Day (February 24th) we are pleased to present you with our timely game of “Whose Stash Is That?” Game.

The game was originally labeled, “Ew, Whose Stash Is That?” but we changed the name after our Photoshop wizard stopped grossing out after she finished defining the difference between upper lip hair and the nose hair of our various unsuspecting entries.

So, without further ado, or blather..



Mustache #1 Mustache #2 Mustache #3 Mustache #4 Mustache #5 Mustache #6





Oh, the glory of them all!

Can you match the man to the stash?

Your options are:

  • Brett Dillon
  • Neil Moyer
  • John Proctor
  • Paul Raymer
  • Dave Roberts
  • Peter Troast

Hope the anticipation doesn’t kill you.

One more note, we did not ask permission… umm. Sorry!

Update:  05/1/2013

Here are your results!

Thanks for letting us play. (And don’t be afraid to celebrate Photoshop!)

#1 – John Proctor


#2 – Brett Dillon #3 – Peter Troast








#4 – Neil Moyer #5 – Dave Roberts


#6 – Paul Raymer


Building Science – The Oldest Profession

Thursday, March 14th, 2013

I had the pleasure of presenting with my good friend Allison Bailes at the recent RESNET conference in Orlando.  While watching Allison present, he made the statement that the Canadians or perhaps the Swedish invented Building Science.  It didn’t really hit me then, but this weekend, pondering my own house and sustainability efforts in preparation for a panel at the upcoming ACI Conference I realized that Allison is perhaps short selling our fine industry.  I think we can make a case for Building Science as the oldest profession.

We’ve been putting dwellings together for a very long time.  We’ve been building huts for at least 25,000 years.  Evidence for even cruder shelter stretches back as far as 30,000 years. It’s very likely that we’ve been crafting rough shelters to keep out of the elements considerably further back than that.  Any of us today working to survive in the wilderness would do what we can to stay  warm, dry, out of the wind and feel more safe than we would otherwise.

Many moons ago I visited Mohenjo-daro (awesome website Dr. Mark Kenoyer!) in Pakistan.  It’s an archaeological site, part of ancient Harappan civilization. It’s somewhere around 5000 years old and had toilets, street drainage systems and a variety of other mod-cons.  You need only look at the archaeological record to see that we’ve been doing building science as long as we’ve been building.  And of course, as we’re human, we’ve been improving as we go, forgetting much of what came before, making mistakes, discovering

new (and old) techniques and materials.  We continually blend the best (and worst – Amish miracle heater anyone?) of what we have today with the knowledge of our forbearers to advance the state of building science.  That is my point really – not only is Building Science the oldest profession – but that we are all building scientists in the applied fashion.  We tweak and adjust our structures, we do stupid stuff, but we also do brilliant stuff.  We orient our tents to face the opening away from the prevailing wind, we orient our homes to take advantage of the sun (except when we do a stupid thing like bring a design from England and plunk it down in New Zealand facing the same direction it did in England – Ooops – the Sun is the other direction down there! – Thanks to Ben Adams for telling me about that).

Vernacular architecture is the fancy term for recognizing that we build our dwellings to take advantage of what’s locally available to us and address the local conditions we face.  We generally make mistakes when we don’t at least understand the vernacular and ensure that whatever design we are proposing takes the same care to address the environment.  We’ve gotten lazy with our vernacular in no small part because of our current (and temporary) abundance of cheap fossil fuel.

High ceilings in hot regions, steep roofs in snowy regions, openings positioned to catch ocean breezes; that’s us evolving, that’s vernacular and that’s building science – we’ve been at it a long time.  So thanks Canada (and Sweden) for “modern” building science, but building science is old, perhaps even the oldest profession.

Steve Byers
EnergyLogic, Inc.

One Big Use of the HERS® Index

Thursday, November 1st, 2012

One of the best (and perhaps obvious?) uses of the HERS index is to enable homebuilders to draw a very clear distinction between the homes they build and existing homes that are on the market.  Much of the focus for builders right now is to distinguish their homes from the glut of existing homes on the market, many of which are priced significantly lower than new homes.  While most buyers certainly know that a new home will be more efficient than an existing home, few have any idea of just how much better any given home is.

Enter the HERS Index, which provides a buyer with a concrete means of seeing just how much more efficient new homes are than existing homes.   For example, a typical home that EnergyLogic performs an energy rating on in Colorado has a HERS Score around 70.  A typical existing home will have a score well above 100, most commonly around 130.  It’s a relative index, with low scores being better scores.  So, a home that is a 70 is nearly twice as efficient as a home at 130.  The HERS Index is the foundation for most efficiency and green programs.  The excellent blog “Nice House, But Is It Legal?”, from the Rocky Mountain Institute has a fantastic graphic showing where various programs and codes fall on the Index.

The HERS Index is a powerful tool for builders to demonstrate the superiority of their product versus the existing home competition.  Builders across the nation are adopting the HERS Index as part of their marketing programs both to compete with existing homes but also to compete with other new homes.  In many areas, builders, working with energy rating firms, are developing marketing plans that have the HERS Index at the core of their message to potential buyers.  The simplicity and multiple value add aspects of performing a HERS Rating; quality assurance, code compliance, process improvement (just to name a few) are making energy ratings ever more sensible for builders today.

Steve Byers
CEO of EnergyLogic

The Pretty Good House High Plains Style

Monday, May 14th, 2012

In keeping with a theme… We were inspired to add a regional perspective to the Pretty Good House idea, written up in the Green Building Advisor by Michael Maines and continued by  Allison Bailes at Energy Vanguard, here is Part 2 of his effort.   I asked our exceptional staff of HERS Raters and Auditors for their thoughts.  Here is Steve Eagleburger with  his thoughts.  Steve is also a PHIUS+ person and quite passionate about PassiveHaus among other things.

(Steve Byers)

So what does that mean? Is current code pretty good? Is Energy Star version 3 pretty good? I would say yes they are. When you compare houses built to code today to houses built say, 20 years ago there have been major improvements. The codification of air barriers is one example. The introduction of house tightness and energy modeling is another. Energy Star version 3 is bringing in thermal bridging issues, duct leakage, quality installation and HVAC system commissioning, all of which leads to a better performing house. So where to go from there? Semantics are everything when selling a product or an idea, so I would say rather than shooting for “pretty good” let’s go for “a little bit better”. How can we get there without major cost and retraining of trades?

First thing to do in our high desert/plains climate is let the Sun in! We have an abundance of free solar energy and it’s a simple proposition to face a house within 15 degrees of South. It may take some educating of developers and planners to swing new suburbs towards the sun but it can be done. We must also control summer sun with overhangs and minimize west facing windows. Here comes the cost issue- builders must start using low u-value/high solar heat gain coefficient windows on the south side. This cost could be recouped by installing fewer windows on the north and west side.

Now that we’ve pointed our house in the right direction we need to insulate and air seal properly. Energy Star and the IECC are heading in the right direction but there are too many loopholes. Houses need to be wrapped head to toe with at least R-5 of rigid foam above grade. Period. Advanced framing does little to reduce energy use. Foundations should be R-20, R-10 under slab, 2×6 R-23(+5) walls and R-60 in the attic. Mechanical rooms need to be treated as exterior spaces and sealed tightly or all appliances need to be sealed combustion. Houses we test are already coming in at around 2 ACH50 or better, so let’s get them down to 1 ACH50.

We can build this way without major retraining or cost adjustments but will the homeowners understand how the home operates? It’s been said that there are no zero energy homes, just zero energy homeowners. As an energy auditor I’ve been in homes built 50 years ago and no one has ever been in the attic. Countless times I’ve seen window shades drawn on a bright winter day. We all know we’re supposed to change the oil in our cars on a regular basis so why shouldn’t we understand that putting a bag over the combustion air inlet to stop that cold air from coming in the basement is dangerous, or that when the Sun shines in it warms up the house, or that 2” of ratty old fiberglass in the attic just isn’t acceptable. So let’s spend some time and resources educating homeowners.

-Steve Eagleburger



Building Science Funnnies – Duck Blasting

Friday, February 24th, 2012

Funny BS – Building Science

Thursday, February 23rd, 2012