Retrofitting Your House for a Post Petroleum World

We all will long to live in a house that’s designed from the bottom up to be comfortable without using tons of energy. However, too many of us have invested too much in our existing houses. We may not like it, but we will be forced to make them work. So what can we do with our energy-consuming monsters to allow us to survive in them?

retrof1What steps will depend more than anything else on whether your primary challenge is staying cool or staying warm. You probably already know, but if you don’t, do this: look at the sum of your electric and gas bills. If they’re higher in the summer months than in the three winter months, your primary challenge is to stay warm. If they’re higher in the three summer months, your primary challenge is to stay cool.

When Your Primary Challenge is to Stay Cool

Understand the basic philosophy of passive solar. Your basic task is to keep the house as cool as possible during the summer.

Start with the Roof

If you must replace it, and you will eventually if you live in the house long enough, replace it with a reflective, light-colored roof. It’s startling how much more electricity people in the southern U.S. are using just because they have a dark roof that soaks up and retains the heat of the midday summer sun.
retrof2Install a ridge vent. There’s simply no reason why any house where the primary challenge is to stay cool shouldn’t have a ridge vent running its full length. If your house doesn’t already have them, and too many don’t, cut intake vents near the bottom of the roofline. This allows the ridge vent to pull in fresh cool air from the outside near the bottom of the roof and vent it at the top.

When you deal with a ridge vent, beware of screening designed to keep bugs out of your attic. These vents are out of sight, out of mind, and there’s no practical way to make sure they’re still working. Over time, any screening that’s too restrictive will clog up, robbing the vent of its ability to do the job you installed it to do. Some screening (for larger critters like wasps) is appropriate, but anything smaller than 1/8 inch or so will eventually clog up with dust, cobwebs, insect wings, etc.

Consider adding a solar water heater. Adding PV panels to your roof for the direct generation of electricity is probably not a good financial investment, but adding a solar water heater probably is.

Adding insulation between the attic and your living space is probably the easiest, quickest step you can take to reduce your air conditioning load. Think in terms of an R value of 40 or higher, even though that may be more than your electric company is recommending.

If you can do so gracefully, add an attic fan. You can use an attic fan on all but the hottest summer nights to pull in cool air from the outside. Yes, it will be humid, but it will allow you to avoid turning on the air conditioner, and that’s the name of the game.

If you have a metal roof, but it’s rusty, here’s a procedure that will make a world of difference.

Retrofit Your Windows

You’ll need most of them to open. Too many houses in hot, humid climates have windows that look great but won’t open and close. It will cost a lot, but if anyone is  going to live in your house in the post-petroleum age, they will need windows that open and close. And make sure they have screens. When you replace the windows, consider replacing them with the kind that have enclosed blinds. The neat thing about blinds inside a double or triple pane window is that the sun’s heat gets bounced away before it reaches the living space.

Windows on the north side of the house won’t take on much heat in the summer from direct solar gain, but windows on all three other sides of the house present problems. On the east and west, you don’t have much choice. Because the sun comes in from so many angles during the day, you simply must have blinds you can close on the east side in the morning and on the west side in the afternoon. Ideally, someone will figure out how to make an exterior blind so the heat will never reach the living space, but we haven’t seen it yet.

The south side of the house will receive heavy, direct sun all day, but it will receive it from high in the sky, so you can shade your south windows with an overhang. If you have a two-story house, the upper south windows may already be shaded, but you’ll need to add an exterior overhang between the first and second floors to shade the lower level windows. Nobody’s making these commercially yet, but don’t worry; they will.

If your house is one of those unfortunate enough to be built facing in an intercardinal direction (northeast, southeast, northwest, or southwest), you’ll need to improvise and compromise with your cooling strategy. Read all about passive solar and think through where you’re taking on the most heat, then fashion remedies that are designed to reduce as much of that heat as you can.

Get Reacquainted with Your Basement

In the post-petroleum era, people who live in big petroleum era houses are going to move around within the house. We will do most of our living in our basements to stay warm or cool during the most extreme seasons of the year and then enjoy the rest of the house during the milder seasons.

If you’re using your basement for storage now, and most of us are, begin thinking about where to move all the stuff that’s stored there. Chances are you don’t need most of it, but some of it is important, and you don’t want to have to live with it in your living space.
retrof1If you’re one of those who has a bathroom stubbed in in your basement but has never installed it, begin thinking about adding it. You’ll be grateful for a toilet close at hand when you’re living several weeks at the time in the basement. And when you install the fixtures in your basement bathroom (or anywhere else in your house, for that matter), make sure it’s a dual flush toilet. These toilets have two flushes available, a quick splash for liquid waste only and a more robust flush (typically twice the volume) for solid waste. You could also consider a composting toilet.

Begin planning now for getting light to your basement. You want to get light and heat in during the coldest months of the year, and if possible, you want some thermal mass to hold on to that heat. If you don’t have south facing windows in the basement, consider adding them, or at least avoid doing anything inconsistent with adding them. And if you do have south facing windows, begin thinking about how you would avoid taking in lots of heat from them in the summer. The easy way to do this for most of us is a shelf overhang that’s tilted in the direction of the winter sun but articulated to block the summer sun.