Weekend warriors, this one’s for you! A more energy efficient house may sound like a big, vague goal, but it’s actually made up of a lot of small changes and updates—many of which can easily be accomplished on a 48-hour timeline. In fact, many of the most effective projects take less than a few hours, which is a pretty small commitment, to say the least, especially when you consider that these home renovations often represent thousands of watts in energy offsets. Besides the instant energy savings, researchers have consistently found that energy-efficiency projects add a sales premium to homes when they close. In one such study, green-rated homes commanded a nine percent sales bump; others have found that there’s about a $15 to $20 premium for every one dollar of energy savings. With money like that on the line, it’s almost like you can’t afford not to make these improvements. Here are our picks for the best weekend-worthy home updates with the biggest energy savings—and the best return for your dollar.

Caulking and Weather-stripping Windows and Doors

Most people think of weather-stripping as a wintertime project, but truthfully, air sealing endeavors like this benefit homeowners any time they run their HVAC unit, not just when it’s windy outside. Sealing leaks in your home’s building envelope buffers drafts, sure. But it also keeps heating and cooling from slipping out cracks in the interior. Excellent air sealing means closing off gaps around any openings in your home, and the area around your windows is a good place to start, since caulking can become cracked and fail with age. To boost your windows’ resistance to air leakage, scrape out any old sealant and apply a new bead of weatherproof silicone caulk around the window glass. Meanwhile, use weather-stripping foam around the moving parts of the window for extra protection. Foam tape works great for doors, too, so hit those up with some weatherproofing while you’re at it.

Install a Ceiling Fan

If you run to the thermostat every time you feel warm, you could be missing out on some valuable energy savings. Ceiling fans cost about 36 times less to operate than central air conditioners—and they’ll actually cool you down faster than dialing down the thermostat. When you come in sweating and hot from the outdoors, the circulating air from a ceiling fan activates a wind chill effect on your skin, so you cool off fast. And ceiling fans are fairly easy for the average homeowner to install. Meanwhile, you’ll save a lot more energy by using your thermostat responsibly: since your AC unit is actually a temperature regulator, switching the dial down to plunging temperatures doesn’t cool you off any faster—it only ensures that the total will be higher when you get your energy bills.

Clean Your AC Condenser Coils

Speaking of your AC unit, there are obviously days where a ceiling fan alone just doesn’t cut it. However, your air conditioner will waste less energy—and keep you cooler—if you give it some regular TLC. In particular, in the spring and fall, most units can use a little attention on their condenser coils. Cleaning this component ensures that your AC’s refrigerant is working up to snuff, but many times outdoor units can become so covered in dust, pollen, and pet hair that they don’t have the same cooling power as before. To keep yourself in the clear, open the unit and give the coils a onceover with a soft-bristled brush. If the coils look extra sodden, however, you may want to call out a professional AC repair person to give them a more thorough treatment.

Turn Down the Temperature on Your Water Heater

This one’s about as easy as they come. Most home water heaters come set to a default temperature of 140 degrees Fahrenheit. But for most homes, about 120 degrees is really all you need—and the excess heat costs your home money and wastes energy. According to the Department of Energy, overworked water heaters are responsible for around $400 on average in unnecessary annual energy expenses. And turning the temperature down to 120 is as simple as finding the thermostat and adjusting the settings. Each water heater is different however, so your best bet is to read your manufacturer’s guide before you get started. Keep in mind, too, that you may have two dials if your unit has an upper and lower heating element. This switch literally takes minutes and can save you from an accidental scalding, too!

Replace Your Thermostat

It seems like everything in homes is getting the “smart” treatment lately—with somewhat mixed results. A Bluetooth toilet? Who needs it? A thermostat that can track your energy use and adjust temperatures on the fly? Now that’s more like it! Smart thermostats help you decipher the temperature algorithm that will net optimal energy savings—without sacrificing comfort in the process. Many of these devices include “learning” features that monitor your manual adjustments to create the perfect self-regulated temperature schedule. And they often include programs that offer tips and adjustments to help you save even more energy. In fact, in certain areas, you can even schedule heating and cooling use during low-demand energy hours, which will save you money if your utility has implemented time-of-use pricing. That could literally represent hours of energy savings and lots of value when you resell. Not bad for a day’s work!

By, Guest Blogger

Erin Vaughan is a blogger, gardener and aspiring homeowner.  She currently resides in Austin, Texas, where she writes full-time for Modernize, with the goal of empowering homeowners with the expert guidance and educational tools they need to take on big home projects with confidence.