Can Big Houses be Energy Efficient?

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  • Transcript

    LESLIE: Well, big houses sometimes get a bad rap from an environmental perspective, with some complaining that they’re energy hogs compared to smaller, more efficient homes.

    TOM: Yes. But size might not matter as much as people think. What matters is how we operate them. Here to help set the record straight is a guy with experience remodeling homes of all sizes: This Old House host Kevin O’Connor.

    Welcome, Kevin.

    KEVIN: Hi, guys. Great to be back.

    TOM: So, the current sort of tiny-home craze notwithstanding, American homes have generally gotten bigger over time, right?

    KEVIN: They have gotten bigger over time and they are continuing to get bigger, despite that tiny-home craze.

    Think about this: the average size of a home in 1950 was 983 square feet. Fast forward to 2013 and the average size was 2,598 square feet.

    TOM: Wow.

    KEVIN: So they are definitely …

    LESLIE: That’s insane.

    KEVIN: It’s insane. They are definitely getting a lot bigger. And while they’re getting bigger, the number of people living in those houses is going down. In 1950, the average household had about 3.38 people. In 2014, it was 2.5, so a lot more room person.

    LESLIE: That’s crazy.

    TOM: But we don’t build them like we used to, do we?

    KEVIN: No, we don’t. And I think this is the thing that’s behind the premise that a big house isn’t necessarily bad. And again, let’s look at some statistics. Homes that were built after 2000, they consume only 2 percent more energy than homes that were built prior to 2000, despite the fact that on average, they are 30 percent larger. We are building better houses. And the only reason that the total home energy consumption isn’t down in those periods is because we’re using a lot more electricity for all of our electronics and gadgets. We use 21 percent less energy for space heating in today’s homes than we do in older homes, despite being so much bigger.

    TOM: So it’s not so much the house that’s wasting energy, it’s all the people living in the house that’s using energy.

    KEVIN: Well, it’s using energy but the point is that we can make a bigger house that uses less energy than a smaller house. And so the size – well, the size is kind of a moot point. What’s important is really how you operate the house. That’s the thing that you really have to look at.

    LESLIE: And I think, you know, you bring up an interesting point. We’re remodeling houses to make them larger. There’s not really a lot of new home stock happening out there.

    KEVIN: Did you build a new house, Leslie?

    LESLIE: No. I’m in a 100-year-old house.

    KEVIN: You bought – there you go.

    How about you, Tom? Did you build …?

    TOM: Yeah, mine’s been in the family since 1886.

    KEVIN: Well, there you go. The first house I bought was built in 1895 and the second house I bought was built in 1950. Very few of us build a new house. Less than half of 1 percent of new – of our existing housing stock are new houses built every year. So the vast majority of the 112 million homes are homes that we buy that are already there. So there’s very little we can do about their size. What we can do is think about how do we operate these houses efficiently.

    And if I move into a big house – let’s say I buy a 3,500-square-foot house but then I go and I add a ton of insulation and energy-efficient equipment, aren’t I taking a lot of housing stock and making it more efficient? I’ve actually improved the efficiency of a big house, which is necessarily a good thing. So you have to think about not the size of the house but what you do with it.

    TOM: So bottom line, Kevin, really, for any size house, if you want to make it more efficient, what are the top things to consider?

    KEVIN: It’s a pretty short list. And as you say, it doesn’t matter what size the house is. This list applies to all houses.

    And the first thing you want to do is you want to make sure that you add insulation. If the house doesn’t have any, there’s a great opportunity to add tons of it. If you’ve got some in there, you often can add to what’s there and improve on what’s there.

    After insulation, you want to think about air sealing. You want to stop the moving air from going in and out of the house, around windows and doors. And around the sill is certainly a place. You can also upgrade your mechanical equipment. Mechanical equipment these days can be 90-, 95-percent efficient. So new equipment will be super-efficient. And then the easiest thing is your electrical load. You can reduce your electrical load very quickly using things like LED light bulbs all throughout the house.

    All of those things will take a big house or a small house and make it more efficient.

    TOM: Great advice. Kevin O’Connor, the host of TV’s This Old House, thank you so much for stopping by The Money Pit.

    KEVIN: My pleasure.

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