The Step-by-Step Guide to Installing an Outdoor Electrical Outlet

Disclaimer: The method described below involves tapping a pre-existing indoor outlet for easy access to electricity. Other options, such as running power cables directly to a new breaker, are possible but should only be performed by a licensed electrician. Always be safe and practice caution when working with electricity. 

Want to bring more power to your backyard? Installing an outdoor electrical outlet can bring light, entertainment, greater access to power tools, and more to your outdoor living space. 

Below, we’ll walk you through one method of installing an outdoor outlet: going through an existing indoor outlet in your home. This project is manageable for DIY enthusiasts, but if you’re unsure about any step of the process, always contact a professional electrician.

How To Install an Electrical Outlet Outdoors

This ten-step process will tell you everything you need to know to turn an indoor outlet into a two-way indoor and outdoor wall plug. Using the access to power already there will make the job much easier and more manageable for a DIYer.

1. Choose a Location

This project begins with selecting the right location for your outlet. The location of this kind of outlet will depend on where you have existing wall plugs in your home, but there are also other factors to consider:

• Convenience: The spot should be accessible outside where you expect to need power. For example, if you have a porch, this could be an excellent place for an outdoor outlet to set up outdoor lighting, power tools, etc. 
• Indoor access: The most basic requirement here will be a spot where you already have an indoor outlet on the other side of the wall. You can mark these spots on your external wall to understand your options.
• Height: To protect the integrity of the outlet and keep it away from water or snow accumulation, position your outlet at least 12 inches above your outdoor ground.
• Local codes: Before installing it, check local building codes to see if there are any specific requirements around outdoor outlet placement to ensure you don’t break any rules.

2. Turn Off the Power Supply

To keep yourself safe through the process, you first should completely shut off the power supply of the area you’re working in. To do this, find your home’s circuit breaker box. These are often in the garage. Then, locate the circuit that powers the indoor wall plug you’ll tap into. Turn the switch on the corresponding breaker to shut off the power. 

Before touching a wire, use a voltage tester on the indoor socket to ensure the power is turned off as it should be. You must never skip this step to save time or cut corners. Even if you feel confident in your home’s breaker system, it’s always better to be safe than sorry about electricity.

3. Remove the Indoor Outlet

With the outlet’s power turned off, remove the cover plate using a flathead screwdriver of the appropriate size. Unscrew the outlet and gently pull it out from the electrical box, exposing the wires behind it. 

Before you do anything else, snap a photo of the wire connections behind the outlet or draw a diagram so you know how to reinstall it correctly later.

Once you have the connection layout saved for later via photo or drawing, start disconnecting the wires from the outlet by unscrewing them from the terminal screws.

4. Drill Through the Outlet Space to the External Wall

Go into this step with a mindset of precision and care. First, knock out a hole in the back of the electrical box or beneath it. Use a stud finder to avoid studs as you drill or cut. Next, find your drill and attach an 18-inch drill bit about ¼ inch wide. 

Approaching the back of the outlet hole at a downward angle, drill through the exterior wall and siding until you reach the other side. The goal is to mark a spot for the exterior outlet just behind and below the indoor wall plug so there’s enough space in the wall to add both electrical boxes back in at the end.

5. Create the Outdoor Outlet Hole

You’ve marked the spot for your new outlet hole. Once you’ve done that, you can swap out the drill bit for a hole saw attachment on your drill to finish cutting the full hole through the exterior wall. 

Try to match the size of the hole to your outdoor electrical box (usually about 2 ⅛ inches wide). For precision, hold the outdoor socket box flush to the exterior wall where you want to insert it and create an outline using a pencil. 

Clean up any debris on the inside and outside created by cutting the hole.

6. Run the Right Cable Through It

Find the suitable NM cable. For a 20-amp circuit, a 12/2 NM-B wire is best, while a 14/2 NM-B wire is better suited for 15-amp circuits. Don’t know what wire to use? Check the amperage listed on the circuit breaker.

Feed it through the hole from the indoor electrical box, and pull it through to the outdoor hole you made until about a foot of cable hangs through on the exterior side.

7. Install the New Outdoor Outlet

Now you’re ready to set up your new outdoor power source:

• Install your weatherproof electrical box from the exterior side of the wall, feeding the cable through it. Attach it in place using screws. (If you’re mounting, this is the point where you can mount it by screwing the clamping tabs tightly until it’s snug up against the wall.)
• Trim the exterior end of the cable so it extends about 4 inches from the box, and use wire strippers to strip about ½ inches from the ends of the wires.
• Connect the wires to the new outdoor outlet following the appropriate color codes:
  • Attach the bare copper ground wire to the green screw of the new outlet
  • Attach the exposed white (neutral) wire to the neutral (silver) screw
  • Attach the exposed black (hot) wire to the common (gold/brass) screw
  • Push the wires and the wall plug into the box.
  • Screw the mounting tabs into the out, add on the cover gasket, and install the cover.

8. Reinstall the Indoor Outlet

Now that the outdoor outlet is all set, get back inside to reconnect your indoor wall plug to your power source. First, use your photo or diagram to connect existing wires to the corresponding terminals on the outlet. Then, add the new wires from your outdoor cable, connecting the black wire to the brass screw, the white wire to the silver screw, and the ground wire to the green screw. 

Tuck the wires back into the box carefully, then screw the outlet back into place along with its outlet cover.

9. Test the Outlets

Turn the power back on from your circuit breaker and use a circuit tester to check indoor and outdoor outlets. Plug in a small lamp or other appliance to test that they function as they should.

10. Enjoy Your New Outdoor Power Source

You’ve successfully installed an exterior electrical outlet, and now you can enjoy this addition to your space.

If you want to maximize the function and comfort of your outdoor space, consider complimenting your new outdoor outlet with other outdoor-friendly power solutions, such as EcoFlow Solar Panels or EcoFlow Solar Generators. 

It could include EcoFlow Rigid Solar Panels, such as the robust EcoFlow 400W Rigid Solar Panel, and an expandable solar generator that can grow with your outdoor power needs. You can even use these solar generators to power your outdoor outlet or connect them to your home.

Want to integrate your solar power into your home more comprehensively? Check out the EcoFlow PowerKits 5kVA or EcoFlow Smart Home Panel.

Frequently Asked Questions

Final Thoughts

Installing an outdoor electrical outlet is a practical DIY project that can transform your backyard into a functional outdoor living space. This guide walks you through one way to do that: leveraging the power access available in your existing interior sockets. Always be safe when working with electrical wires, and refer to a licensed professional with any questions or concerns. 

If you’re on a mission to maximize your outdoor power, consider other options to complement your new outdoor outlet, like EcoFlow’s Solar Generators, which provide flexible and sustainable energy for all outdoor electricity needs.