I know it sounds like an odd question. We tend to think of using solar design for houses, not clothes. I’ll explain.

If you know it’s a cold day, do you think about what you’re going to wear? Of course you do. You might wear several layers. The layering forms more tiny air spaces around you and increases the insulating effectiveness of your clothing. You might pick out dark colors. Even if you don’t think of this as “passive solar dressing,” it is. dark colors absorb the radiant energy from the sun better than light colors. I’m sure when you’re outside on a cold, but sunny day, you walk on the sunny side of the street to stay warmer than you’d be on the shaded side. Ah! Passive solar principles, again. It’s nothing more than proper insulation and receiving the free energy benefit from the sun.

Insulation is important, so let’s not forget your hat. We always hear that we lose the most heat through our heads. Your house loses the most heat through the roof. Heat moves upward as hot air rises. So wearing a warm hat is like putting good insulation in your attic and roof. It’s the place where the investment produces the most benefit.

We do the same thing in the summer, using passive solar principles to stay cooler. Don’t you choose light colored clothes? Light colors reflect the sun’s radiant energy. You’ll stay cooler. A light colored roof in a hot climate will keep your house cooler, too. Don’t you pick clothing that breathes so you’ll stay “ventilated?” Natural ventilation in your attic will reduce your air conditioning expense. It won’t have to work as hard. With the right ventilation in many climates, air conditioning may not be essential, even on the hottest days. On a hot summer day, you might also wear a hat with a big brim. That’s like having a house with proper overhangs to shade the walls and keep the house cooler. The shading keeps you cooler whether it’s a hat or a roof.

I wrote another blog post last winter about using solar energy to help clear my driveway of snow.  It’s rare to get much snow where we live in North Carolina. But it happens from time to time. Hey, if Mother Nature is giving us free energy, we might as well use it. It’s simply a matter of understanding how to use it.

If you would like to read more articles about house and home design, please visit my other website, www.about-home-design.com.

Metal roofs, now often referred to as “cool roofs,” can act like your light colored, open weave shirt and keep your house cooler in hot weather. They do this “passively”, that is they use no electricity in the process. Here’s why they work. In an article posted at Classic Metal Roofing Systems website, they list four energy benefits you’ll get with a metal roof.

1. Thermal Mass. Mass is the “weight” of a material. Stone has more mass than wood because a chunk of stone weighs a lot more than a the same-sized chunk of wood. Heavy asphalt roofs have a lot more mass than metal roofs. The higher the mass, the more heat a material can absorb. Although metal can get quite hot to the touch, it does not store heat in its mass and it will give up it’s heat more quickly soon as the sun goes down, or behind a cloud, or even when a breeze blows. So just like your open weave shirt, the material will cool down easily. Aluminum is even better than steel in this regard.

2. Color. Just like your light colored shirt, a light colored roof will absorb less radiant heat. I wrote a blog post about how I use passive solar principles to help clear snow and ice from my driveway. And color was the key. Here’s a link to that article, if you’re interested: http://www.designingyourperfecthouse.com/blog/2009/01/passive-solar-design-on-my-driveway/

3. Reflective Pigment. In the Classic Metal Roof Systems article, they say “Many dark-colored metal roofs now have reflective pigments so that good reflectivity is achieved even in dark colors.” This means that you are not limited to a silver or white roof to enjoy the benefits of an energy efficient, highly-reflective roof.

4. Integral Airspace. Metal roofs do not lay tightly against the roof sheathing. This means that a gap of air is created that insulates the roof sheathing from conducted heat coming from the metal. This airspace acts like a trivet or a pad you might place beneath a hot pan to keep from burning the countertop or table in your kitchen. Asphalt roofs lay tightly against the sheathing and continually conduct heat into your attic or rooms below, adding to your air-conditioning expense.

No matter what roof material you choose, be sure to provide sufficient attic ventilation. Metal roofs do not replace this essential design feature. But metal roofs will keep your attic and house much cooler and keep your air-conditioning electrical costs down significantly.

Metal roofs tend to cost more, initially, than shingle roofs. I’m researching this and looking for ways to control the added costs. I’ll report on this in future posts. If you have any experiences with metal roofing and the energy benefits, please post a comment. I would love to hear from you.

If you would like to read more articles about house and home design, please visit my other website, www.about-home-design.com.

    I was in San Diego recently and visited the part of town they call Old Town San Diego. I don’t think the buildings are the actual original structures, but they are reproductions that are authentic to the mid 1800′s. One house La Casa de Estudillo, is built in the Spanish Colonial style of the early California settlers. You can see from the photographs that it is built in a “U” shape with a covered veranda wrapping the inside of the “U”. In the center is an outdoor space that is planted and has a water feature in the center.

Green and Sustainable Building in Old Town San Diego

    This is passive solar design at its essence. The climate is dry and the sun is harsh. So what did the builders do? They shaped the building so as to create a protected courtyard. The hot sun is kept from streaming into the windows and the thick adobe walls don’t heat up in the sun because they are shaded by the veranda roof. This prevents them from radiating heat into the living spaces. In fact, the high-mass adobe walls will hold the cooler nighttime temperatures, providing a measure of cooling that requires no electricity. After all, they did not have that luxury.

Veranda Roof is a Key to Passive Solar Design

    The air that moves beneath the veranda roof is cooler than the air of the sun-drenched desert, so any air that enters the room is also cooler. The shape the building and the use of the veranda as a corridor between rooms means that every room will have openings on two sides so that even the smallest breeze will ventilate the room.

    The courtyard is protected from the desert climate making it easier to grow plants that would not survive the desert. But beyond the practical benefits, the courtyard adds to the sense of security. And isn’t this the emotional definition of “home?” It’s our safe haven.

    It’s these simple principles that we should be incorporating into our “modern” designs to reduce our demands for energy. The pleasant by-product of designing in this manner is that the spaces become more inviting and comfortable for people. Rooms with daylight on two walls are wonderful. Transition spaces, such as verandas, improve the quality of the spatial experience. Smooth transitions from outside to inside soothe our souls.

    And what’s more sustainable than adobe clay, sun-baked clay tiles for the room, and timber cut from the immediate area. Trees, when managed properly, are a very renewable resource.

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If you would like to read more articles about house and home design, please visit my other website, www.about-home-design.com.

    House design mistakes are all around us. Unfortunately, we tend to look right by them. But I’m on a mission to point some of these out, just to raise the bar on what we “demand” of the marketplace in terms of house design. Often, the mistakes could have been easily avoided, if only someone bothered to think about what they were doing. Here’s the photo of DHF #2 again:

Dream House Fumble #2

    What caught my eye here was the little roof above the garage door. This kind of a roof that’s attached to a wall is what I’ve always called a “pent eave.” That might be an old, northeastern building expression. Now that I live in the south, I hear this type of roof called a “watertable.” No matter what it’s called, it should be positioned lower on the wall so it can look like it’s doing its job of sheltering the garage doors. In this application, not only does it deny its purpose, but it interferes with the geometry of the gable roof above it. I suppose the architect was intent on getting wall-mounted light fixtures above the garage doors so they had to move the roof up to do it. Or maybe the lights were added to fill up wall space once the problem of the pent eave roof location was discovered. Who knows!

    There are other problems with this house that we could discuss, such as the lack of a proper entry experience by presenting the garage doors first instead of the front door, the “glued-on” brick front, the troublesome little downslope of the driveway that directs rainwater into the doors, and even the questionable use of keystones above the long, flat garage door heads. But we’ll save those topics for future posts.

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If you would like to read more articles about house and home design, please visit my other website, www.about-home-design.com.