Thursday, February 26, 2015

"The Worst House You Can Legally Build" continued

It's kind of interesting that today on the Green Building Advisor the blog post of the day is "Grumpy Architect Time" in which Robert Swinburne, the architect, lists things that irritate him. And what is number 2? You guessed it. Here are the first 2 on his list.

"1. If your house is adequately insulated there should be little temperature differential between the ceiling and the floor.

2. "Adequately" differs from code. Remember, a house built to code is the worst house you can legally build."

He has gone through additional training to be a Certified Passive House Consultant to really take building energy efficiency to a new level - the Passive House standard which is the most stringent building standard in the world.

Saturday, February 21, 2015

Building to Code - Building the Worst House Allowed by Law

If you think about building a house to the minimum level required by the building code, you are actually building a house to worst standard allowed by law. In other words, you're not building to a good standard or a reasonable standard, but to the lowest level possible. Why would anyone do that?

Obviously in this blog, my focus is on energy efficiency and making a home environment comfortable and healthy. So when I think about building or renovating a home, I think how can I make this home more comfortable, more energy efficient within reason (which usually means within financial reason) as opposed to what is the LEAST AMOUNT OF INSULATION I can get away with.

Energy standards for residential buildings are covered by the International Energy Conservation Code (IECC). These codes are updated every 3 years and adopted by individual states in the US. You can see in the map below that the majority of the states in the US are covered by the IECC 2009 code (states in blue). That's true for SC where I live.

Adoption of International Energy Conservation Codes by State

International Energy Conservation Code Zone Map

So what does that mean in terms of actual energy conservation? Specifically, for South Carolina that means that my attic should be insulated to an R-value of 30, my wood framed walls to R-13. If my house was built over a crawlspace the floor should be insulated to R-19. I've got a basement so that doesn't apply. My house was built in 1954 so truthfully none of these standards apply which is part of problem - why I am not comfortable in my house this winter. 

R-value as you know means resistance to heat flow. So what does it take to meet these rather lax requirements for my zone 3 home? Here is a chart I've made showing various types of insulation with R-values. 

Type of Insulation Material

Added just because the northeast is buried in snow

Wood is not really an insulation material but listed here for comparison since it is the major building material for most homes in the US and is about 25% of the frame in a home.

Wood Insulation board
Agepan is a wood-based OSB type panel imported from Germany

Fiberglass (loose fill)
2.2 - 2.9

Fiberglass (batts)
2.9 - 3.8

Cellulose (loose)
3.1 - 3.8

Cellulose (wet spray)

Cellulose (dense pack)

Mineral Wool (loose)
2.2 - 3.3
Also called stone wool, made from volcanic rock and recycled slag
Mineral Wool (batts)
3 – 3.8

Mineral Wool (board)

Depends on density of the product
Cotton (batts)

Wool (batts)

Really, wool as from sheep
Foamglas (board)

Cork, expanded (board)

Cementitious (foam)
2.0 - 3.9

Phenolic (foam)
4.4 – 8.2

Polyisocyanurate (foam)
5.6 - 8.0

Polyurethane (foam)
5.6 - 8.0

You can make some broad generalizations that simplify the calculation for how much insulation you need. First wood has an R value of 1per inch and that makes up 25% of your wall. Second, most fibrous insulation (that includes cellulose, fiberglass, mineral wool, and denim) range from about 3-3.8/inch. No significant difference in R-values between them really. The foam materials roughly range from 4-6/inch in terms of effective insulation. So you pick either a fibrous insulation or a foam insulation and go from there. I'm anti-foam insulation for the most part so I would exclude that now. (Maybe another post some time down the road.) So to reach an R-13 wall, I need 3.7 inches of fibrous insulation which not coincidentally is about the space provided by a 3.5 inch stud wall. To reach my attic insulation requirement I need about 8.5 inches of insulation.

Where am I now in my cold little house? I had all new vinyl windows installed about 10 years ago, then about 5 years ago I had my house covered in 2 inches of polyisocyanurate foam for a R-10 continuous layer on my walls and new siding over that. What I have not done is insulate my attic because I have a leak around my chimney despite having it "fixed" about 4-5 times and I may to have to take a ceiling down when I renovate my kitchen. The R-value of the compressed fiberglass batts that do not cover the entire floor of the attic might be 6-8 at most. That's where most of my heat goes. That is the main reason I am in fleece long johns, wool socks, multiple sweaters and still cold despite the heat pump running constantly. 

This house was built to code in its day. When energy was cheap, you just ran "Old Bessie", the ancient old heater (since replaced) constantly and kept warm. That doesn't work today and it won't work for the future. We have to do better with our houses. We will be happier, more comfortable, and have healthier places to live if we think past code minimums. 

Thursday, February 12, 2015

Leaky Walls - Infrared Photos on vacation in Montana

I just purchased a small infrared camera that attaches to your iPhone. It's called the Flir One. It's a little awkward to use because of the way it's attached to the phone (you have to take your phone out of whatever case it's in and insert it in the Flir One case which is a tight fit).

I used it a little bit when we went on vacation.

Here are a few photos.

The first one is from our hotel room in Bozeman, I believe. Obviously the dark colors are colder and the lighter colors represent warmth. You can see the leakage at the corner, you can see where the individual studs are in the wall. I wonder if they are metal studs because heat is conducted so much more effectively through metal. But the striking thing is the serious cold air at the intersection of the floor and the wall.

The second photo is from Big Sky, I think. Same problem, serious air leakage, cold air infiltration at the corner of the room where the walls intersect the floor. 

This view shows a seriously under-insulated corner stud.

I need to go over my house and take some photos. I have not done so yet because the daytime temperatures outside have been so close to my inside temps that it wouldn't show where the heat is leaking out and the cold is coming in.

Wednesday, February 11, 2015

Door installation with Exterior Insulation

I don't have a big readership of my blog which is fine with me. I mostly put the construction stuff out there to help anyone else who might be trying to build or renovate a better, more comfortable, more energy efficient house. Every once in awhile I get a question about the actual construction of John's house and I certainly want to help if I can.

One reader asked a question about installing the doors with the exterior insulation, the Roxul mineral wool Comfortboard. Here's the question:

Hello, wanted to say great job on the house! 

Im currently gutting a 1930's bungalow down to the frame & sheathing & am planning to add roxul comfortboard to the exterior. I see you went with the approach of mounting the doors and windows to the outside of the now-thicker walls. The windows are easy, but I'd like to see or hear about how you did the doors. Did you fir out the door opening, mount the door to the outside of the thicker wall, then trim the difference inside? If so, does this stop the door from swinging open fully? Thanks for any input on this detail....there is so little info online about the door installs on these exterior insulation jobs.

From looking at the photos the doors were installed on the outside of the thicker wall and trimmed out on the interior. It probably does prevent the door from opening more than 90 degrees. Here are some photos that might help explain it better than I could.

Back Porch Door with Polyiso around the edges, taped

Back Porch Door Opening

Front Door Framing with tape before installation
Close-up view of door framing
Installed Back Porch Door showing the thickness of the wall
Front Door Sidelights installed
Another Porch Door fully opened - looks like it opens just past 90 degrees
The only 2 articles I could find that address this issue are listed below. Green Building Advisor (GBA) is the single best place to get information. You do have to sign up to ask questions, but it costs nothing as a regular member and you get great advice from people who know their stuff.

Here is a similar question on GBA to the one you asked:

This is an article in Fine Homebuilding where they address your question when double stud walls are used:

So I hope this is helpful.