roof

Part 5 of our 15-part Q&A series on all aspects of green building from the publishers of HealthyHouseInstitute.com. Click here for the introductory post and furthur details.

Question: Aren’t wood windows best from a health standpoint?

Answer: Wood windows are usually treated with water-repellent and fungicidal chemicals. So, while wood is a natural material, treated windows can certainly bother some sensitive people. Also, they’re usually made of pine which can have a strong natural odor. Furthermore, wood windows require routine painting. However, wood windows usually aren’t strong outgassing sources. Therefore, these concerns are only important for very sensitive people.

Vinyl windows are a less-expensive option. While they never need painting (a real plus), the vinyl itself can outgas a little—especially when new—which can be enough to bother some sensitive individuals.

Personally, we prefer aluminum-framed windows. Most are available prefinished in white or brown, and they require little maintenance. In cold climates, you should look for frames with thermal-breaks to minimize sweating. Aluminum windows generally have rubber or plastic seals that have a slight odor—but it usually isn’t significant.

Multiple panes of glass are a good idea in harsh climates for energy efficiency. Low-E coatings and argon-filled windows rarely cause health problems, and we think they’re important to conserve energy.

Question: Is there a healthy window putty I can use?

Many people understand that their homes or commercial buildings will leak energy. They also understand that over time it will hurt the environment. The problem is that it isn't a big deal to them because they can't see it. It is like telling a 16 year old that the sun can damage their skin. They don't see it happening so they don't worry about it. The easiest way for me to let people know that stick building, even if it does have decent insulation, is not efficient is with a picture. Building with Structural Insulated Panels (SIPs) is the best way to reduce energy leaks.

SIPs are a strong structural system consisting of Expanded Polystyrene (EPS) insulation which is laminated to oriented strand board (OSB) forming a structural panel.

Now let me show you why. These two buildings are almost identical, located in West Virginia each has about 6,000 sf of roof. The photo on the top will show the thermal imaging while the photo on the bottom will show you what we are looking at with the naked eye.

The building on the left was stick built while the building on the right had a roof constructed of Structural Insulated Panels (SIPs) You can see the roof has multiple large "hot spots". The building on the right is a nice consistent purple showing that there are little to no leaks. The parking lots and road retained heat so they show up as yellow and orange.

Below are the same picures from the other side.

Again the stick built building (now shown on the right) has obvious hot spots while the SIP roof (now shown on the left) has no heat loss.

The use of SIPS greatly reduces energy loss. The direct benefit of using SIPs is that there is less energy loss and in turn there are less greenhouse gases being let out into the atmosphere. So while you can't always see the effect our choices have there are consequences, short term and long term. People can help the environment and themselves if they choose green building materials.

Kevin,

I plan to build a straw bale home within a clearspan steel building in the Olympia, Washington - Portland, Oregon area.

The den and dining areas will be on open decks in the plaza and the plaza will have a Japanese garden with a Koi pond. But, the question is of roof color. Is it cheaper to produce solar heat to heat or thermal cooling to cool the building? In other words, should the standing seam metal roof be white or silver, or dark in color?

Danny

Danny,

This sounds like an interesting project, although I can’t quite visualize what you’re up to. There is always a quandary about heating and cooling the building. We want the sun to heat the building when it’s cold outside and yet keep from heating it when it’s warm out. Ideally, in the winter everything including the roof would be dark colored and un-shaded during the day, to soak up as much heat as possible. Then, it would be wrapped up in a big blanket at night to keep all that heat in. In the summer, it would be insulated, light in color and shaded to protect from any heat absorption. So, what do we do?

The simple answer is:

1. Insulate the walls and ceiling very well to keep the temperature from being affected greatly by changes in outdoor temperatures.

2. Make sure all windows are dual pane to let in natural light while accomplishing the same as the insulation.

3. Put a light colored roof on the house. Since you are insulating between the roof and the interior, any heat gain on the roof is only going to create what is called the Heat Island effect, where sun is absorbed and released to heat the atmosphere unnecessarily.

Good Luck!
Kevin

Image sxc.hu, Henk L