How to Run Electricity to a Shed

Running wire to a shed is an excellent way to turn a simple outbuilding into a multi-functional space. Powering a shed involves several steps but is within the capabilities of the typical weekend warrior.

Wiring involves careful planning, as you have many options to choose from in terms of method and materials – here’s how:

  • Plan and prepare the job
  • Plan the circuit
  • Draw shed wiring diagram
  • Select type and size of wire
  • Choose the right conduit
  • Dig the trench
  • Install switch box
  • Run the conduit
  • Pull the wire
  • Connect circuit to main box and switch
  • Wire the shed
  • Call an electrician

An important note to consider is that although you are wiring the shed yourself, you must get approval from a licensed professional. Otherwise, you risk fines or potential damage to your property.

How to Run Electricity to a Shed

Wiring a Shed Regulations

When working with electricity, you are going to need a permit. Believe it or not, but nearly any electrical repair you make in your house or shed requires one from your municipality. Installing a new light fixture in your living room?

Probably going to need a permit. What about putting in a new dimmer switch? Also requires a permit.

Have a look at this document from the City of Atlanta as an example of when a permit is and is not required by most cities and states. If you live in a rural area and are not within the limits of a municipality, you only need to follow NEC guidelines.

Most of us won’t get a permit for installing a dimmer switch or a pot light or two as any DIY novice can safely complete those jobs. But for bigger jobs, such as running power to a shed, a permit is a must.

A permit protects your shed in case of fire. If your shed burns down due to wiring, insurance will not cover your loss if you neglected to get a permit.

Secondly, when you go to sell your home and you’ve done electrical work without a permit, this will be an issue for potential buyers. Thus, you could lose value on your home. Spend the money to get a permit, and you’ll maintain value on your home and peace of mind.

Running Power to Shed without Permit [Risks and Consequences]

Before you run your wire without a permit, consider this: building permits are a matter of public record. Why is that important? Let’s say you live in a dense area where space is at a premium.

You are running wire near a neighbor’s property. The neighbor decides he’s going to be a pain. One simple phone call to the town hall is all it takes for him to find out if you have a permit.

Then what? If a building inspector comes by and sees you’ve done work without a permit, he’ll shut you down until you obtain that permit, and likely levy a nice fine in the process. Some inspectors will even order you to tear down the work you’ve completed.

Another issue to consider is when you go to sell your house. It is not mandatory to disclose what you renovated and did or did not get a permit for when you sell.

However, a discerning home buyer or agent may check to see if you’ve taken out any building permits. If not, a buyer may hesitate before purchasing a property that hasn’t been given clearance by a local building department.

If you wire your shed without a permit and then sell your home, you are liable for any issue that might arise for the new owner unless you’ve clearly stated and signed a document stating you’ve completed work without a permit. A lawsuit may occur if you’ve falsely declared, or neglected to declare that you’ve completed work without a permit.

Lastly, running power to a shed without a permit is unsafe. Permits exist to keep people safe. An inspector will ensure you’ve done the job correctly.

If you don’t get a permit, and you’ve wired your shed improperly, a fire could result and insurance won’t cover the damages.

Do I Need a Sub-Panel for My Shed?

If you are thinking about running more than one circuit in your shed, then yes, you need a sub-panel. Remember, a circuit is just a group of receptacles, fixtures, or switches connected by a path of electrical wire.

Some sheds will have more than one circuit, particularly if the shed doubles as a workshop. Lights and 15A receptacles are typically on one circuit, while another circuit may have a 20A breaker for heavier tools such as a table saw, small air compressor, or a grinding wheel.

NEC requires any outbuilding to have a shut-off switch or breaker that shuts off power to the building. If you put more than one circuit in your shed without a sub-panel, then that would require you to run more than one wire from your home to the shed.

This is against code. Only one wire is allowed to run between your house and an outbuilding.

On the other hand, if you only plan to use a miter saw and a couple of lights in your shed, then you could likely get away with a single 20A circuit. In this case, a sub-panel would not be necessary and you would only need a single switch at the entrance of your shed to toggle shed power and meet code.

Run Power to Shed Options

When running power to a shed, you have several options. Your location, how far away your shed is, what type of ground you have, and more are considerations that affect what type of cable you run and how you run it to your shed. Below are options for running power to your shed.

Extension Cord

An extension cord is likely the most common way people run power to their shed. The problem with this is that it is not permanent and is also not safe in bad weather.

When you go to sell your house, you cannot advertise your shed as “wired” because an extension cord cannot act as a permanent power source.

Pros:

  • Cheap
  • Simple to set up and remove
  • No permit required

Cons:

  • Not permanent
  • Unsafe in wet weather, and a general ground hazard
  • Does not add value to your property

Cable Above Ground

Electrical wires must be buried or strung overhead, out of reach of curious humans. If you live on bedrock but want permanent power to your shed, then burying cable from your home to shed isn’t an option.

You need to use a cable above ground. While not typical, this is a viable method of running power to a structure.

Pros:

  • Solution for compact ground-types
  • Permanent, code-approved solution
  • Does not require digging

Cons

  • May require an electrician
  • Permit required
  • Requires heavier gauge wire than burying

Direct Burial – UF (Underground Feeder) Cable

Direct burial cable is made to be buried directly in the ground without conduit. The casing around the wire is thicker, keeping water out and makes for a fairly stout connection between home and shed.

On the other hand, you’ve still got a wire without any external protection inches from the surface of your yard. While code allows UF cable, it may not be a good fit in all locations.

Pros:

  • Simple installation
  • Cheap – no conduit required
  • Best option for stable soil types

Cons

  • Susceptible to damage from earth movement
  • Harder to replace than conduit

Underground Conduit

Wire Encased in PVC Conduit is wire run from the house to shed within PVC tubing. The PVC tubing begins at the house as it exits through a header, masonry, or another part of your home.

It then extends underground, unbroken, all the way to your shed, where it reappears and runs up to your switch.

Wire in Rigid Metal Conduit acts the same as PVC but is stronger because it is metal. In areas where high traffic or digging is expected, this may be the best option.

Wire Encased in Flexible Metal Conduit is when you need something stronger than PVC, but have to route the wire in a trench that has many bends or curves. In this instance, a flexible metal conduit may be more practical.

Rigid metal would require numerous fittings, whereas the flexible conduit would need only one piece since it can flex with the contour of the trench.

Pros:

  • Added layer of protection
  • Easier to replace wire in conduit

Cons:

  • More expensive
  • Time-consuming installation

How to Run Electricity to a Shed Guide

Running power to your shed requires thorough planning. Once you determine how you will run the power to your shed, and what materials you’ll need, then the job can be accomplished relatively quickly. Unless you are digging a 100 ft. trench, but even then you can rent a tool for 4 hours to complete the job.

Required Tools

  • Wire strippers
  • Pliers
  • Screwdrivers’
  • Cordless drill
  • Electrician’s fisher tape
  • Shovel (optional)

Required Materials

  • Wire
  • Switches, receptacles, and boxes
  • Circuit breakers for panel
  • Conduit (optional)
  • Sub-panel (optional)

Step 1: Planning and Preparation

First, you need to see if your current electrical panel has enough space to run the wire to a shed. If you have a small house and a 200A panel, then you most likely have enough space.

On the other hand, if you have 100A panel, you might not have enough space to run power to a shed safely. In that case, you need to hire an electrician to upgrade your electrical service to 200A.

Once you determine your panel can support power to a shed, you’ll want to figure out how much power you are going to supply to your shed. What tools or machines will you operate in your shed that will require power? Will it include a freezer? Do you have a large compressor or welder?

Even though you will not likely use multiple tools at once, it is better to overestimate the number of amps you’ll need.

Next, you need to figure out how you will run power from your main panel to your shed. Remember, you are only running one wire. If your panel is in the basement, you will be running the wire through the header to reach outside.

Since you will be digging a trench to cover the wire, you’ll want to dig the shortest possible trench to save your back. This usually means a straight line; thus, you’ll have to get your inside wire to the point in your house that is closest to the shed. That’s where you’ll drill a hole to run your wire externally.

It’s important to note that everyone will have a different experience when wiring a shed because no two homes are alike. If you have a finished basement or a crawl space, then you might find an alternative way to get your wire from your main panel to the outside. However, the principles in this guide still apply.

Step 2: Plan the Circuit

As mentioned in step 1, you will only be running one wire to your shed. But what if you are going to have more than one circuit? You will need a sub-panel. A shed sub-panel allows you to have multiple circuits up to the capacity of the shed breaker in your main panel.

If you install a 60A breaker for your shed sub-panel, then your sub-panel can handle three 20A circuits or four 15A circuits. You want to ensure you’ll have enough power for the life of the shed.

On the other hand, if you plan only to have one circuit that includes a few lights and receptacles, then no sub-panel is needed. In this case, you’ll only need lights, receptacles, wire, a switch, and maybe some conduit.

Another point to consider is if you want to supply 240V instead of 120V to your shed. All lights, most outlets, and appliances operate at 120 volts.

Larger equipment needs 240 volts, like a dryer or electric range. Running 240 volts to your shed requires using a different type of breaker in your main panel, different wire, and a sub-panel in your shed.

A wire that reads 6/3, for example, is good for 240 volts. It will have two hot wires, one black and one red, as well as a neutral and ground wire. On the other hand, 6/2 wire is for 120V only and has just one hot.

If you want to use your shed only for one purpose, like welding and you want one 240V circuit, there are lights that are rated for 240V, negating the need for a sub-panel.

Once you plan your circuit(s) in the shed, you’ll want to assemble the materials. Calculate the amount of wire you’ll need, as well as staples, receptacles, boxes, lights, and switches.

Step 3: Draw Shed Wiring Diagram

A wiring diagram is a map for an electrical system. Not only will a wiring diagram allow you to properly assemble all the materials you’ll need to complete your shed wiring job, but it will also make visible any issues with circuits.

When doing electrical work such as installing new circuits in a space, it is easy to forget load amounts and amp ratings. Writing it all down on paper ensures circuits are not overloaded and allows you to choose the most efficient route for installing the wiring.

Keep in mind that installing a sub-panel to run your wiring is not as big of a job as it sounds. A sub-panel is a vehicle to install more circuits in your shed in the future. Take a look at these diagrams to get an idea of what a wired shed sub-panel can look like.

Step 4: Select Type and Size of Electric Wire

You cannot run any type of household wire to your shed. Your first consideration needs to be what gauge of wire to run. Gauge refers to the thickness of the metal within the wire. The heavier the gauge, the larger the load that can be carried.

When considering what type of wire to run, a chart like this is important. If you are running a couple of circuits to a max of 30A, and the length of the run is about 50 feet, then you’ll need this type of wire. Consult the chart to see which gauge of wire you need.

Another point to consider is the voltage drop. Voltage drops as it runs through the wire.

Typically, this drop is very low and doesn’t affect service within your house. If you are running wire to a shed and you have to go longer than 100 feet, then voltage drop may be an issue.

Use this calculator to see if the voltage drop between your shed and house is enough to recalculate the type of wire you use. If it is less than 3%, then you are within NEC recommended drop and are good to proceed.

Step 5: Choose the Right Conduit

If you do not want to use direct burial cable, then you will be running your wire through conduit. Conduit is just another word for tubing in which the wire sits for added protection. Extra wet, cold, or busy environments should consider conduit.

PVC conduit is a cost-effective way to run wire. It is cheap, easy to cut, and can bend to fit slightly curved trenches. The main drawback with PVC is that NEC states that it must be buried at least 18″ deep. If you only have yourself, a shovel, and 150′ trench to dig, then this could be a problem.

On the other hand, a metallic conduit only needs to be 6″ deep. More sturdy than PVC conduit, the metallic conduit will stand up to the most rugged environments and you don’t have to dig an extra foot.

The downside is that the metallic conduit is much more expensive. There are two types: flexible and rigid. Not all flexible metallic conduit is rated for outdoor use, so check the labels carefully before purchasing.

Confusingly, conduit comes in many different sizes. Go by the rule of thumb that your wire shouldn’t take up more than half the space within the conduit.

Since you are only running one wire through your conduit, 1″ conduit should be more than enough. You’ll have to pull the wire through the conduit, so going wider makes it easier to pull your wire through.

PVC conduit comes in different thicknesses, called schedules. The higher the schedule, the thicker the PVC.

If you are installing your PVC conduit in areas where it might get damaged, a higher PVC schedule is a good idea. Your wires will be harder to pull, however, so upgrading the diameter of the conduit is advised.

Step 6: Dig the Trench

Once you’ve planned your wiring and purchased your wire and conduit, it’s time to dig your trench. As stated above, PVC conduit must be at least 18″ deep. Metallic conduit needs only be 6″ deep, at minimum.

You have options for how the wiring enters your shed. You can run the wiring underneath the shed and have it go through the bottom stud and up into the structure, or you can have it run up the exterior wall and then go in through the wall.

It depends if you want a switch or panel on the exterior of your shed. Either way is acceptable.

If you are installing a sub-panel, then NEC states that you’ll need a grounding rod to ground your sub-panel properly. A grounding rod is an 8 to 10′ piece of copper or galvanized metal driven into the earth and connected with a single copper ground wire to your sub-panel.

Lastly, remember to call 811 before any digging or go to their website. If you live in an urban area, or you aren’t sure, then you need to protect yourself before you start digging and hit a gas line.

Step 7: Install Switch Box

Once you’ve dug your trench, it’s time to install your switch or sub-panel, depending on what type of circuit you have decided to install. Your switch or panel can go on the inside or outside of the shed. If going outside, make sure it is rated for outdoor use.

Step 8: Run the Conduit

When running the conduit, you’ll first need to start inside your home where the wire runs to the outside. The wire running from within your home to an external source needs a weatherproof exit.

If run through the header of a house, you will drill a hole the same diameter as the conduit you intend to use. A short piece of conduit to an external junction box will suffice.

Remember, your wire should run from your main panel to your shed. Using regular Romex indoor wire and then switching to the exterior wire at the point of exit is not recommended.

Be sure to caulk around the exterior opening. The junction box will then allow the conduit a 90-degree turn to go down into your trench. An elbow piece in the trench will turn the conduit 90 degrees again to run the length of the trench.

If using PVC conduit, there is PVC cement that will bond conduit to fittings. Be sure to apply thoroughly, as it will create an impermeable seal that will make your conduit weatherproof.

Step 9: Pull the Wire

Once you’ve got your conduit set up, running from your home to the shed, you’ll need to pull the wire through your conduit using electrician’s fishing tape. If you’ve never used it before, picture a long, skinny, metal wire with a hook at the end.

Feed the tape through the end without the wire. When it gets to the other end, attach it to the wire. Pull the tape. It might take some persuasion, but it will come.

When attaching the wire to the eye of the fishing tape, be sure you secure it with a tight loop. Also, stagger the individual wires that you loop through the eye. This creates a more aerodynamic shape for the wire, allowing it to travel through the conduit better.

Step 10: Connecting the Circuit to the Switch and the Main Box

The main service panel of your home will have a dedicated breaker devoted to your shed. Ultimately, this is where you determine how much power your shed is going to have. If you want your shed to be 60A, then you’ll install a 60A breaker in your service panel.

Also, the amount of voltage you supply your shed occurs at the service panel. A 120V service to your shed involves using only a single-pole breaker. A single-pole breaker has only one hot terminal, as opposed to a double pole breaker which has two hots, allowing you to draw double the voltage or 240V.

Whatever you choose, make sure you install the appropriate wire for the job, consulting the charts linked earlier in this guide. When installing a new breaker, shut off power to your house and carefully install the breaker into an empty space in the panel.

On the other end, you’ll install your wire into either a sub-panel or a switch. If you’ve already connected the wire to the main panel, ensure the breaker is in the off position. Wire the switch accordingly and be sure it is rated for 240V or 120V, depending on what type of power you run to your shed.

If using a sub-panel and wiring for 240V, be sure to disconnect the metal bridge connecting the neutral and ground bars. Neglecting to do so risks electrifying all metal components of your shed’s electrical system. Wire your panel to a ground rod using copper ground wire of appropriate size.

Important: your shed needs a shut-off switch either at the sub-panel or immediately after for each circuit. Sub-panels themselves do not require a single shut off, but you need to make sure each circuit has a switch that can turn the entire circuit off. Code mandates the switches must be easily accessible in case you need to turn off all power in a hurry.

Step 11: Wire the Shed

Now it’s time to fully wire your shed. If you’ve chosen to use only one circuit, then the wiring is fairly straightforward. If you are using a 20V breaker, then 12/2 wire is recommended. If your circuit is only 15A, then you can install 14/2.

Be sure to use wire staples, where applicable. Wire staples keep your wiring flush to the middle of your studs. In case of a stray nail or screw into the studs later on, the staples keep the wiring safely out of the way.

Sheds require the use of GCFI receptacles. These receptacles install the same way as traditional outlets but cost a little more. Or you can use GCFI breakers instead, which will make all receptacles on that circuit GCFI.

Step 12: Call an Electrician

Once you’ve wired up your shed, you need to call an electrician to get everything checked out. The electrician will ensure all work completed is safe and up to code. Once the electrician has come to check your work, the way should be clear for the building inspector to give his final inspection.

This is the most important step. You can plan and take your time, but inevitably you are going to make a mistake. Mistakes and electricity can have disastrous results.

Wiring a shed involves messing around in your main service panel, an area that is critical to the operation of your home. Do yourself a favor and pay a little extra to get the added security of a professional’s stamp of approval.

How Much Does It Cost to Run Electricity to a Shed?

The great part about wiring up your shed on your own won’t cost you an arm or a leg. The major cost will be your wire. If you are using copper wire, which is common, you’ll have to pay more for thicker gauge wire. Since you are running power some distance from your house, a heavier gauge than typical house wire is going to be a necessity.

If running a moderate length of wire, say 100′, then a coil of 8/3 direct burial wire is going to cost you around $170. Heavier gauges don’t typically come in smaller coils, so if you are running 100A to your shed at a distance, you may need something like this. At over $600, the cost of that wire may have your rethink your power priorities.

Sub-panels themselves are not expensive. This one is rated for outdoor use and is under $40. GFCI receptacles, boxes, and switches are also cheap. Be sure switches and light fixtures are rated for the proper voltage if you are running a 240V circuit.

Lastly, your conduit can be expensive if you are using rigid metallic conduit. 100″ of 1″ rigid metallic conduit will run around $100. Flexible steel conduit of the same length and diameter is double the cost of rigid conduit. PVC is the cheapest option and clocks in at around $75 for 100′ of 1″ conduit.

Conclusion

The most important aspect of this job is safety. Switching off your main power breaker when doing panel work is an obvious must. As is keeping the power off when wiring your shed. But the most important part is acquiring a permit and getting an electrician to check your work.

After you’ve taken all the safety precautions, be sure you’ve thoroughly thought through your power requirements for your shed. Overestimating is always a better idea than underestimating.

So if you have even a little doubt that one 15A circuit is all you’ll need for your shed, then you better reconsider. It’s easier to do it right the first time.

As always, thank you for taking the time to read this guide. I hope it helps you when you go to run power to your shed. If you have any questions or comments, please feel free to drop me a line, below.

Leave a Comment