GIMME SHELTER- Retro green: Making a '70s gem energy savvy

Alec Cargile
Lithic Construction


Q: I'm thinking of buying one of those simple, "modern," open-floor-plan houses built in the early 1970s. Unfortunately, it was built when gas was 50¢/gallon, and it's about as energy efficient as a chicken coop– big single-pane windows, high ceilings with no attic space, thin layers of old fiberglass insulation. Is there a way I can upgrade the house to make it more energy efficient without completely breaking the bank?

A: Installing new weather stripping on your windows and doors is an inexpensive first step, but if you really want to make the house more energy efficient, you'll have to accept some financial sacrifice. There are a lot of variables to work with, so it's important first to know how much you have to spend. To reduce costs, it's best to avoid any extensive renovations.

Where you can get to your existing insulation– crawl spaces, attics, etc.– you'll want to replace the fiberglass insulation with some kind of spray foam insulation. Back in the '70s, people with little or no training usually installed the fiberglass insulation, and given that builders and home buyers weren't as concerned with energy efficiency back then, there wasn't the same attention to detail. Unfortunately, if you have fiberglass insulation in your walls, you're going to be stuck with that unless you opt to tear them out. Recently we put spray foam insulation in the attic and crawl spaces of an older house, and it made a dramatic difference in terms of energy efficiency.  

Windows are a huge point of heat and cooling loss, so investing in storm windows is a good idea. You'll also want to replace those big single-pane windows with double-insulated glass. This can be expensive, but you get what you pay for, as the energy loss from single-pane windows is also huge. 

If you don't have an attic, you might want to think about stripping the roof, putting down foam board, and then re-roofing. That's not cheap either, and design-wise it can be difficult not to make your house look like it's wearing a bad sombrero, as it raises the roof about three inches. But there's a lot of energy lost through a poorly insulated roof. 

If you haven't blown your budget, you may also want to look at the mechanical systems. Is your duct work properly insulated? Are the connections tight? A poorly designed duct system can waste a lot of energy.

Finally, with high ceilings, you need to be able to mange air flow in the house, either by installing fans or calling in a pro to analyze how air flows. Air flow is important when it comes to using energy efficiently.