All about low-e windows and SHGC

Low-e glass, like that used in the Andersen windows of the i-house, is manufactured with a microscopically thin and transparent layer of metal or metal oxide that reflects infrared “heat” energy back into the home, greatly enhancing the thermal performance of the window.

There are two kinds of low-e glass, hard coat (pryolytic)  and soft coat (sputtered), and they fall into three levels:

1. Low-e glass with a low Solar Heat Gain Coefficient (SHGC, 27% of solar heat transmitted, 64% of visible light transmission which is abbreviated VT on window specs) reflects and keeps much of the sun’s heat energy out, but not light, out of the home. This is the best choice in warmer climates dominated by cooling.

2. Low-e glass with a medium Solar Heat Gain Coefficient (39% of solar heat, 70% of light), for climates that use both heating and cooling equally.


3. Low-e glass with a high Solar Heat Gain Coefficient (71% of solar heat, 75% of light) that allows the sun’s heat energy into the home. This is for climates that require very little cooling, and most of the energy cost  is for heating.

A single pane of regular window glass has an R-value (insulation value) of only .85 whereas a low-e insulated window will have 3.5.  That is a significant difference, in a window's ability to hold the heat in, especially in a house with as much window area as the i-house.

For example, here in Santa Fe, the highest summer temperatures are around 90 degrees, and few people have air conditioning. There have been summers where I didn't even use a fan once. So, I would want the #3 Low-e with HIGH Solar Heat Gain Coefficient. It keeps the warmth in during the winter, but lets in most of the hot sunshine.

Low-e coatings weren’t offered until 1979, so the main window in my living room, for example, is completely un-coated, which lets in 100% of solar heat.  It is very good for solar gain in the winter, but doesn’t keep the room heat in well, so I cover it with a thick blanket at night. I have queried Clayton and will update this post when I get an answer on the values of their windows, and if they offer a high solar gain window for people in colder climates who want to take advantage of passive solar heating from the Sun.

This information on SGHC of low-e windows might be a thing an individual dealer might say “doesn’t really matter.” Yet, an architect doing solar design, would definitely incorporate the best kind of window for a specific purpose and location. I hope you find it helpful no matter what home you’re looking to buy, or especially if you are shopping for replacement windows.

Here's a video of a rep explaining low-e glass. He doesn't even get into the Solar Heat Gain Coefficient issue:

Here is a brief explanation of SHGC and when he gives a value of .4 that translates to 40%, which is a SHGC suitable for warmer climates. The lower the SHGC value, the more heat from sunshine the window will block.

No news on the debut of the i-house II, but in the meantime, why not check out my most recent post on the little solar home by Cavco, in my other blog, Greenotter's Manufactured Home Reviews.

For those you who wanted a separate guest bedroom with bath, but can't afford the i-House, check out my post on Palm Harbor's Avanti III. It is a clean modern design with a beautiful interior, 2 bedrooms and 1-3/4 baths all for $70,000. There's one for sale at a dealer in Oregon.

Poor man's i-house

As I was making the rounds of manufacturers’ web sites, this stopped me in my tracks.

I think it is made by Marlette (owned by Clayton), out of their Hermiston, OR factory, and this model is for sale is at a dealer in Everett, WA, THE HERITAGE HOME CENTER.

The 700 sq. ft. one bedroom, one bath, “Value Edition 1440A” model pictured, has a base price of $34,000, but with the upgrades, like the photo, it is $56,000. Even the V-roof is a $7000 upgrade.

It is pretty nice looking but with a 8’ flat ceiling inside, and insulation of R22 (floor), R11 (walls), and R22 (roof), it just doesn’t…well, the Karsten SF 50, with an additional two bedrooms and bath, super insulation, and a 9’ ceiling, and lower price, would be a better buy.

It comes with 2 x 6” walls, which is good, and putting R-21 in them would be no problem, since this is built at the factory where the ihouse is made. If you’re interested, ask about stuffing more insulation in the roof too.

One thing I like about this particular design, the porch roof is extended more than on the i-house

What I like about dealers in the Northwest, is they sell single-wide homes with 2 x 6” walls because of code requirements, which seems to be a problem in the South. California and the Northwest have the strictest codes.

In ihouse 2.0 news, they’ve presented an improved floor plan, with a more open kitchen, which is a no-brainer. They‘ll probably be turning out a few for customers later this summer.

How bamboo flooring is made

THIS FLOORING VIDEO from the DIY (Do-it-Yourself) network's DECONSTURCTION program, shows how bamboo flooring is made. It is a full program comparing different types of flooring, including carpet.

They demonstrate how bamboo flooring is stronger than oak flooring.

HERE IS A LINK to another DIY video, this one all about WINDOWS. After seeing this informative video about windows, click on WATCH ALL 25 DECONSTRUCTION episodes to see what other topics might be of interest. Using this link search service at the top you can also do a search for other cable shows about fixing up or looking for a house, like Sweat Equity, My First Place, House Hunters, or Property Virgins.

Here's another DECONSTRUCTION episode I liked, about granite counter tops. In one test, they show an advantage to solid surface counter tops (the upgrade on the ihouse), since if you drop a glass, it is less likely to shatter than on granite. They cite a statistic I didn't know... in new homes, 48% of counter tops are now granite.

Here's a link to one of my favorite episodes from PROPERTY VIRGINS, a show which takes first time home buyers through the selection and buying process. This particular show is in Toronto (so Canadian dollars) and I like the last house. It shows how comfortable spaces in a smaller home can be, especially in a colder climate. Each episode is similar. First the couple or buyer is taken to their dream neighborhood where the Realtor brings them down to earth about what they can really afford.

Having the how-to-fix shows on the internet is especially handy since even though they are on cable, the HGTV channel, the internet makes it easier to locate and watch something specific to a project you're considering. Plus, I don't have cable!

The home-search shows are educational and entertaining because they show the decisions all people have to make -- ones like location vs. size -- no matter what price level they are looking at. Even people with over a million dollars to spend sometimes have to choose between the one with the best view, and the house with better interior.

HOUSE HUNTERS is staged. They find a couple who has already bought a house, but hasn't moved in, and take them on a mock tour of two others. Still, it is enjoyable to watch as the viewer doesn't know which house they bought. I like the host of PROPERTY VIRGINS, if only for telling people they probably shouldn't take a sledgehammer to a brand new tile counter top, because they want granite, if money is at all a factor.

One show I saw had a kitchen with new white appliances, and the buyer said she'd change them to stainless steel, "to increase the value of the house." That doesn't make sense. The only way stainless steel appliances are going to do that is if she lives there for ten years, and then buys new stainless steel appliances when it comes time to sell the house.

ihouse on the DIY network

Clayton ihouse 2.0 coming soon

Fill 'er up!












These are the plans (see note in red below) for the new larger ihouse 2.0. I like that they've added more overhang to the roof, but don't think they should have stuck with a butterfly roof design. It's bad enough getting leaves and blown dirt out of gutters but to have a large roof configured in a shape that collects them...

2017 note: The i-house was in production for only a few years, and any plans for a doublewide i-house 2.0 are long dead.) Don't despair! With Warren Buffet's money, Clayton will come out with exciting things, just as they did with this 2015 AMIE 3D-printed carbon fiber prototype house in cooperation with Oak Ridge National Laboratory and others. 

Here's Preston Koerner's take on the plans for the new ihouse, from JETSON GREEN.

I'll have more to add to this post when I look at them more carefully. It certainly doesn't look like it is going to be cheap, but the people clamoring for a larger house should be happy.

Here's the offical ihouse 2.0 plan form, where you can write about all you like and don't like about the house plans. (Frankly, this is what they should have done for the first incarnation! It's a very good idea.)

First Clayton ihouse in Santa Fe, sort of

Click on photo for large size, and use BACK button to return to blog.

The ihouse and New Mexico skies go well together don't they? And it is only a few blocks from me! I know it well, because I put it there myself, with Gimp. (Free software like Photoshop.)

I might do another post on how this is done, if anyone is interested. Since the ihouse is quite different looking, most people might want to try doing this before buying the house, using a photo of their property.

I used my photo of the model in Albuquerque and then Gimped it in a photo I took of nearby land, in 347 easy steps. Well, to do it roughly would be easy and take only 10 or 15 minutes, but the refinements I did on this one took much longer.

Curious as to what the ihouse would look like in all galvalume?













Here are the two photos I combined:

You can see I even took out the reflection in the core unit's sliding door of a neighboring house, and also took the stickers off the transom windows.




This photo is eight miles outside of Santa Fe city limits, on the plain. Most of Santa Fe is not this void of vegetation, but it is where I live. However, I have views of four mountain ranges from my property, and my house was the least expensive property I could find that was habitable, when I bought it five years ago.

For those of you who want to try it HERE are my instructions of how to do it in Gimp.

Previewing wall paint colors on the Clayton ehome

Previewing wall paint color on a Clayton ehome, using software. from Green Otter on Vimeo.

For full screen, click on the 4-arrow symbol to the left of the word "Vimeo" in the lower right. When it is done playing, press Esc key to return to blog.

Did you ever have a great idea to paint a room or a wall a certain color, and wish you could preview a number of colors before you begin?

Once I felt inspired to paint my bedroom a deep forest green. When I finished, it looked like a nightmare. So I painted it over, with beige.

Using a photo of the ehome, I devised a method to preview a number of colors on the walls. This is the “B” kitchen in the largest ehome. It helps to have a photo of a room that is white or light color. Medium or darker colors wouldn’t work as well as a base photo.

Using Photoshop-like free software called Gimp, plopping down the ehome on a photo of some open land a few blocks from here was easy. Doing the colors for the metamorphosing room was another matter. That took all morning.

This ehome kitchen, didn’t look good in white, but as I discovered, it was just a matter of changing the base color of the island, and then it looks okay. You can see that near the end of the video. However, probably the safest color for this kitchen, is beige. Believe me, in my own house, I’m not always safe…I use metallic colors, day-glow orange, (both of the latter only as trim), French wall, painted doorway arches.

If I had a new house though, I’d probably be safe.

White looks great in some rooms, and I thought it looked good in the ihouse, not so much in the ehome, but in general, I like a warm color on the walls, even if it is very light.

There’s some basic rules about choosing wall colors, that I’ve often ignored, and regretted doing that.

One is that you MUST hold the paint swatch up to the place you are painting, to see the color in that place, before you buy the paint. Beige in the store lighting, or outdoors, can look green, yellow, pink or gray when it gets on the wall.

The other rule is that the color looks much stronger once the wall is painted in it. Select a very light green, even if it looks white, until you hold it next to some white, when you get it on the wall, it will look green.

Which colors would I choose?

Click to make larger.


I'm leaning toward this chocolate mousse for the bar base, and burnt Cambrian umber glazed in a....just joking, I'd probably go with brown and deep orange.

Incidentally, the music playing in the background of the video is Ravel’s Introduction and Allegro, for harp and other instruments.