Framing & Roofing

The Corrigan Rug Cleaners of Winchester, VA had a building that was 1375 square feet and was a traditional stick built structure. The building did not have air conditioning and they use heat to dry the rugs. Now they have a Structural Insulated Panel (SIP) building that is 4800 square feet with a drying room that is 80 % larger than their previous one.

What are SIPs? SIPs are a strong structural system consisting of Expanded Polystyrene (EPS) insulation which is laminated to oriented strand board (OSB) forming a structural panel. The panels resist warping and racking. They are especially cost effective when strength, comfort, performance, and energy efficiency are demanded by the building owner, designer, and builder. SIPs can be used for walls, roof, and floors. Here are the price differences of the two buildings. Keep in mind the new building is three times larger than the original building and has air conditioning which the previous building did not.

Month Electric Gas
2007 2006 2007 2006
January $109.81 $281.84 $202.40 $348.78
February $260.93 $207.14 $242.96 $370.48
March $231.73 $324.04 $151.69 $347.07
April $226.35 $202.34 $80.82 $235.34
May $205.41 $145.49 $23.47 $136.56
June $312.95 $148.26 $23.77 $69.76
July $223.38 $164.94 $17.66 $68.09
August $300.34 $177.06 $21.30 $34.76
September $281.50 $165.36 $19.14 $102.84

Total $2,152.40 $1,816.47 $783.21 $1,713.68

The new SIP building uses a two zone 3 ton and 5 ton radiant geothermal heating and cooling system and a radiant heated floor. For 2006 in a smaller building they spent $3,530.15 for gas and electricity. For 2007 in a building three times larger with air conditioning and a larger drying room they spent $2,935.61 for electric and gas. That is a savings of $594.54. The numbers were over the course of nine months for 2006 and 2007.

This is only one example of how SIPs can save on heating and cooling costs. Not to mention that the new building is amazing to look at. You walk into an open area with high ceilings. The Eagle Rigid Spans give the space an almost timber frame look. The SIPs had pure white paint applied directly to them. There are three garage doors that are only moderately insulated which open directly to the main area in the back of the building. Even after they have all been opened it takes only minutes to feel the temperature return to normal. There is a mezzanine overlooking the entrance which had decorative concrete imbedded with the company’s logo . This is a very impressive structure which has allowed them to grow their company without having to expand on their energy budget

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

Kevin & Co.,

You mentioned a sealer or primer paint that can seal over old boards that contain formaldehyde, etc. What brand is that, please?

Thanks!
Byron Savage

Byron,

That would be Safecoat Hard Seal. According to livingreen.com, “when applied properly it is particularly effective at sealing in pollution or outgassing of toxic chemical compounds from surfaces.”
Thanks for writing,

Kevin

photo by Dominic Morel

Hello Kevin,

I stumbled across your site and was impressed with its polish. I applaud your efforts and wish you success.

I hope you will address how using steel frame in a straw bale virtually erases the green benefits of straw, however. The embodied energy in the manufacture of steel is huge, and makes your green project a paler green. It will take you decades to pay back in energy efficiency the energy debt you incurred by using steel. And since you are teaching about building green, other builders or owners might be misled into thinking steel is the way to go.

Now, conscious choices are better than unconscious ones, and it looks as though your project has a lot to offer. I would simply suggest that you address your use of steel in this project and recommend against it for your viewers.

Thanks for your time,

John