The Basics

Home energy use: what is it? That might seem a little too basic, but don’t worry, I’m not going to take us back to high school physics and whether an electron is a particle or a wave. The point here is that if you have at least a rough idea of where energy is going in your home, it’s easier to understand when and how you can effectively reduce that energy use.

Obviously every home is different, but the U.S. government periodically conducts a residential energy data survey that provides a good foundation for understanding where you’re using the most electricity and natural gas, or potentially propane or heating oil. (You’ll notice that this website deals only with the United States, since that’s the country I know the most about. But it’s also because we’re among the world’s biggest greenhouse gas emitters on both a total and per capita basis — lots of room for improvement here.)

The most recent federal data, from 2015, shows that the three main uses of energy by residential customers were space heating, cooling, and hot water heating. For those with a home swimming pool or hot tub, the associated pump and heater are also big energy hogs. Otherwise, lighting, refrigerators, and televisions round out the top tier, with other individual appliances and electronics well behind. So as you’re prioritizing your efforts to reduce your climate footprint – and to save money – the key items to think about are:

HVAC (heating, ventilation, and air conditioning)

Hot water heater

Pool or hot tub pump/heater (if applicable)

Lighting

Refrigerator

Television

I’m not saying to ignore the rest entirely, but if you’re not inclined to mess around with monitoring individual appliances and don’t want to worry about when you plug in your cellphone, you can probably look to this list as the best place to focus any conservation efforts and spending. Of course, use your common sense; if you’re mining Bitcoin in your basement, your energy usage may look fairly different.

The When

I’ve enjoyed spending thousands of hours of my life pondering energy issues, but let’s be honest — I’m weird. Most of you have better things to do with yourselves. The good news is, there are really just a few specific times when it’s most important to focus on how you can lower your household energy use (details on the how coming up below). Those are:

1. When you move.

2. When you buy a new appliance or home electronics.

3. When your utility (or someone else) offers to help pay for something.

Of course, if you’re stuck in line at the hardware store and your mind just happens to wander to whether you need to go buy LED Christmas lights ahead of the holiday rush, go for it. But the takeaway here is that you should always try to find a few minutes to think about energy conservation at these three key junctures.

The How

A New Home

Let’s begin at the beginning: a new home. Trust me, I know energy efficiency is not generally the top priority when you’re looking for a new place to live. Even if you’re really dedicated to reducing your climate footprint, maybe it’s fifth or sixth on the list. But there are two things to keep in mind here. First, high utility bills can be a hidden cost that may make your home less affordable than you think — you don’t want to blow your monthly budget when you find out your August air conditioning bill is a hundred dollars more than you anticipated. It’s good to know if you’re getting a lemon or a Cadillac, to mix the home and car metaphors. Second, even if your dream home has a few flaws on the energy front, knowing those when you pick up the keys means you’ll be ready to plan (and save) for any important efficiency improvements once you move in.

Is It a Lemon?

For the baseline issue of whether your new home is efficient or not, there’s unfortunately not necessarily going to be any great reference point. If you’re extremely lucky, you’re looking at a home that has been evaluated and assigned a Home Energy Rating System rate or a Home Energy Score. Both of these types of scores offer an evaluation of a building’s relative energy efficiency — sort of a “miles per gallon” rating for a home — based on its specific characteristics, and are worth asking about; you can also look up homes by street address or zip code in the U.S. Green Building Registry to check on publicly available Home Energy Scores in your area. If you’re looking at a larger multifamily building, it may have an ENERGY STAR certification or score through the U.S. Environmental Protection Agency. Certification is reserved for the top-performing buildings (at least the ones where the owners are willing to go through the certification process), but any score above 50 means the building is above-average based on standard energy usage metrics.

Of course, the vast majority of homes you look at aren’t going to have these types of ratings available. A more likely avenue is to try to get your hands on the utility bills for the home you’re looking at - ideally at least a year’s worth — by asking the property owner or real estate agent.

Then the question becomes: what do those bills mean? Is $50 a month for natural gas a lot or a little? Is 15,000 kilowatt-hours of electricity usage per year a crazy amount? Wasn’t it really hot last August when these people spent $300 on utilities? What is going on here?!

This is part of why energy efficiency is hard. But don’t give up! I can provide a few helpful pointers to get a high-level sense of whether the home you’re looking at is an energy efficiency star or a real lemon. First, you should check out a great calculator put together by HVAC guru Nate the House Whisperer (more on him in Step Two). This tool lets you plug in the square footage, annual electricity usage, and annual usage of other fuels like natural gas or propane, then spits out — based on real data, I swear — a conclusion as to where the home sits on the energy efficiency spectrum for your region. Note that this is most applicable for a single family home and overall isn’t an exact science, but other than a HERS score this is about the best resource out there.

One more place to look is a 2016 analysis by the real estate listing company Trulia which looks at median utility costs by zip code. You can pretty easily crunch the numbers from this to get a median utility cost per square foot for comparison to the home you’re looking at — but remember your water bills, since they included those in addition to electricity and natural gas, and again keep in mind that this is a rough cut for a median home.

Beyond these options, you may need to be a bit of a home efficiency detective. How old is the home? Often, older means less efficient, since over the decades building codes have raised the bar on requirements for insulation and overall home efficiency. Likewise, how old are the appliances? If there’s a brand new hot water heater or HVAC system, those are likely to be pretty efficient. Is the seller or landlord trumpeting a big insulation upgrade within the last few years? Not a bad sign. Of course, if you’re looking to take on some efficiency improvements or appliance purchases yourself, this may not matter much to you, but you always want to know what you’re getting into. Last but not least, some “anecdata” can come in handy, if your friends and family nearby can offer their take on whether the utility costs seem high or in line with what they’d expect.

Can You Make Lemonade?

You’ve signed on the dotted line and gotten that huge sofa moved in – congratulations! Now it’s time to make a plan to tackle your home’s energy usage. 

This is when I’ll introduce you to a key motto of any energy nerd anywhere: “you can’t manage what you don’t measure.” In other words, it’s a good idea to bring in a professional to do a home energy audit using tools like a blower door test and infrared imaging to check on where you may have gaps in insulation, “leaky” doors and windows, or other issues that result in wasting energy on heating and cooling, that biggest category of energy usage for most households. This process will result in a report identifying some of the easiest steps you can take to improve your home’s efficiency, as well as any larger investments you can make like new insulation. In many places you can get a discount on an audit through utility or state programs, often at a savings of hundreds of dollars. If you can afford it, this is the best way to get a snapshot of whether your home is a good candidate for some cost-effective investments in energy efficiency.

If you’re a renter – especially in an apartment or multifamily building – the picture is somewhat different. In a few places there are programs that will provide an energy audit for your home or unit, but for the most part your best option will be to invoke the time-honored power of any tenant: complaining to the landlord. As we all know, the squeaky wheel gets the grease; or in this case, the leaky window gets the weather-stripping. Even if you don’t pay the utility bills for your rental, as I noted before, many of the same efficiency investments that will lower a home’s energy usage will also make it a more comfortable place to live year-round.

For those of you who are masters or mistresses of your own domain: if you can wrangle an energy audit, great. You’ll then be in the hands of an actual energy professional who has a handle on what your home’s strengths and weaknesses might be. Listen to them for what to do next! They may recommend some quick, relatively easy items like air sealing to reduce leaks or filling in gaps in your insulation; or maybe they’ll suggest more significant investments like a new AC unit or a big insulation revamp. It’ll be up to you to ask some questions and then figure out what makes sense for you based on your budget to make your home comfortable and climate smart. A few ideas for what you might want to find out:

• How much will each item cost? Pretty much what you’d want to know for any home improvement, so I don’t think I need to elaborate on this one.

• What’s the “payback period”? This is the geeky term for how long it will take for your bill savings from making your home more efficient to offset the costs of the efficiency investment you have in mind. It can be as short as a year or two if you’re making a big improvement — e.g. from incandescent to LED lighting — but 5 or 10 years is not unusual. That’s why knowing an estimated payback period may be important depending on whether you plan to be in a home for the short- or long-term. Keeping in mind that this is always an estimate since it’s hard to predict energy costs and utility rates very far in advance, this information can give you a sense of whether you have a realistic chance of saving money overall by spending some up front. Also, keep in mind that in Step Three you’ll get some pointers about how certain “smart” home technologies can help you maximize your bill savings along with your climate impact by shifting your electricity use to times when energy supplies are cheapest and cleanest.

• Will this make my home more comfortable? If an efficiency investment will pay for itself during the time you’ll be living in your home, and you have the financial resources to afford it, that’s what we call a no-brainer. The harder decisions are when you’re considering something like replacing insulation that may cost a few thousand dollars and pay for itself over 8 or 10 years, but you’re planning to have kids and move to a better school district in a few years, or you don’t love your neighbors and think you might do some house-hunting down the line. If you’re not sure an efficiency improvement is a good idea based on dollars and cents alone, it’s still worth thinking about whether it’s worth it in terms of your quality of life. The same problems that cause energy waste (especially with respect to heating and cooling) can also make your home an uncomfortable place to live, whether it’s because of mold, indoor air quality issues, or annoying hot or cold spots. (I speak from experience here!)

• Will this improve my home’s resale value? Okay, no home performance contractor or energy auditor is likely to be able to answer this one with a ready yes or no. But if you’re thinking about pulling the trigger on a big-ticket item even though you may move before it pays off , it could be worth a conversation with a local realtor about whether your home might be more marketable with some targeted efficiency improvements.

• Is this a good use of my “climate budget”? New concept alert! Here’s the deal: making your home “climate smart” may cost money at each of these steps. Part of why you’re here is probably because you realize that and want to spend your money wisely, at least until that whole lottery ticket thing works out. That means it’s worth thinking about how much you feel comfortable spending toward the goal of reducing your climate footprint. That will be a different number for each person, and involve not just financial questions but potentially some deep thinking about your life philosophy. I have some suggestions about the key questions to ask when figuring out your climate budget here — but it’s ultimately up to you to come up with the answers.

A New Purchase

Don’t worry, this one’s fairly simple (with a couple caveats, because if it were really that simple then you wouldn’t be bothering with this website). Bottom line: if you’re buying something new for your home — especially one of the “top tier” from above (HVAC, hot water heater, pool/hot tub pumps and heaters, lighting, refrigerator, or television), then you should buy a model that’s not going to needlessly waste energy. In the United States, the federal ENERGY STAR label offers a pretty reliable guide to purchasing the most efficient models of many products. If you’re buying an ENERGY STAR-certified product, that means it can produce significant energy savings without sacrificing product performance, those savings levels have been certified, and the U.S. Environmental Protection Agency has crunched the numbers to calculate that any price premium is made up for by the savings in energy costs over a reasonable period of time.

Before you start your online shopping, though, a few quick notes. For the HVAC and hot water heater categories (and pool/hot tub heater if applicable), you should make sure to go read Step Two first because you’re going to want to look at electric options. Likewise, check out Step Three for an explanation of why to consider whether certain purchases (e.g. a pool pump) have “smart” or “connected” capabilities.

Finally, you should also read the next section below — because you may be able to save some time and effort in picking a doohickey of whatever sort by getting some expert advice. There’s a whole behind-the-scenes infrastructure that’s probably not on your radar involving a bunch of engineers, economists, and yes, some lawyers like me, all trying to figure out whether it makes sense to offer incentives for consumers to switch to cleaner and/or more efficient technologies. They can’t make your decision for you, but they may be able to help.

A New Discount

Whether you’re a baby boomer, millennial, Gen Z, or whatever arbitrary demographic category we come up with next, you’ve probably learned not to trust advertising. I’m with you. Even with products you may actually like, it can be hard to see an ad and not get an uneasy feeling that they’re trying to put one over on you with a catchy jingle or a heartwarming story. But there’s at least one context where you should try to suspend your disbelief: when you’re offered an incentive by your utility or a similar entity to buy something that’s more efficient/energy-saving/whatever the tagline. All over the United States and beyond, there are many experts (some of them are friends of mine) who spend a lot of time trying to figure out how to make our energy systems less costly and more environmentally friendly. Sometimes, that requires a little help from you — for example, in using less energy to reduce high demand that drives up prices for everyone. (Think about what happens to gas prices at popular travel times like Memorial Day or Labor Day weekend.) Sometimes, the benefits of reducing energy use are so great that these experts decide it’s worth spending money to give people a small “nudge” — through a product rebate or a contractor incentive — to get them to make energy-saving choices that lower overall costs for everyone.

The end result of that decision may be a flyer with your utility bill, an email with a discount code or link to an online offer, or a “home energy report” recommending available programs to reduce your energy use. I’d recommend you actually glance those over instead of immediately putting them in your recycling or your trash folder. Or if you’re even vaguely considering whether you could do something to make your home more efficient, you should check out whether there are any relevant offers on the website for your local utility or state energy agency - some utilities even have an online “marketplace” where you can buy a product and get an instant rebate. In the U.S., the easiest place to start is with the federal ENERGY STAR product rebate finder. (That site won’t necessarily cover incentives for other categories like home energy assessments or audits, special rates (more on those later), or refrigerator recycling, so make sure you cast a wide net in your search.) You may see promotions at your local big box or hardware store, or there are even businesses that can help you search offerings from a range of retailers and identify applicable rebates or incentives, like Enervee.

Are these incentive programs necessarily going to be the right fit for you? No. There may be a clothes dryer rebate when you just bought a new one, or a discount on insulation for a single family home when you’re in an apartment building. The main point here is that these programs and promotions don’t exist just to try to sell you something. They’re out there because someone smart has done a fair bit of math and engineering analysis to decide that they make sense to save energy for a lot of people. Often that same someone has even calculated that it’s worth chipping in a bit of financial help to help you make a change sooner rather than later, because of the resulting benefits for all energy users who get a cheaper price or cleaner air when your home is more efficient. The moral of the story: it’s worth taking a hard look at energy efficiency programs even if a new smart thermostat wasn’t on your to-do list for the month. But ultimately, for this and all the other decisions we’ll talk about, you have to be the one to figure out what’s a smart choice for you. Just make sure you know all the options first.