According to Section 210.52 of the US National Electrical Code, there shall be an electrical outlet in every kitchen, bedroom, living room, family room, and any other room with devoted living area. They must be spaced at least six feet apart along the floor line. If there is not enough space for a conventional outlet, then you can use a powered phone system or networked control devices instead.
The NEC requires that all outlets have their own breaker or fuse panel and be controlled by one switch or rocker/dial mechanism. This ensures that if one power point goes bad, you will still have electricity flowing to other points on the circuit. However many homes from the early 20th century- today do not have separate breakers for each outlet, but rather only one master breaker that controls all outlets on the circuit. This is known as a "single-control" circuit and should never be done without a licensed electrician overseeing the work.
If you are lucky enough to have house wiring that is already configured this way, then there is no need to change anything. But if your home was built after 1990 and has single-control wiring, you will need to get these changes approved by a licensed electrician before they can be made safely.
There's a good explanation behind this. If you want to know how big your wall should be so it has an outlet, just measure the distance from the center of one outlet to the center of the next and multiply that by two.
For example, if you measure 12 inches between outlets, then you need a 24 inch wide wall space for an outlet box. The outlet will need to be located on the interior side of the wall.
You should also know that only one electrical connection can go into each outlet, so make sure you don't have anything bulky plugged into both sides of the outlet.
The reason why this is important is because electricity is transmitted through wires. Where those wires are placed affects how far they can transmit that current. So if you put a lot of weight on an extension cord or try to plug several things into one outlet, it could cause the wires inside the extension cord or power cord to break down before everything gets its share of electricity.
Also see our post about how many outlets should be required by law.
Every kitchen, family room, dining room, living room, sunroom, parlor, library, den, bedroom, recreation room, and similar room or area must have a receptacle outlet installed so that no point along the wall space is more than 6 feet, measured horizontally along the floor line, from a receptacle outlet [210.52 (A)]. (...) Other rooms, such as bathrooms, laundry rooms, and storage areas do not require receptacles if they are not used as sleeping quarters or for storing valuable items.
If you are not sure whether your room meets this requirement, check the manufacturer's instructions or contact an electrician to be safe.
The term "receptacle" is any device that accepts electrical power from a plug and provides it to another plug or circuit. Receptacles include outlets, light switches, and heaters but not power strips or fuse boxes. A replacement part for a receptacle is called a plug. Wall-mounted lights are available in several styles including flush-mount, semi-flush, and exposed. These options determine where you will find the housing for the screw terminals that connect to the wires of the lighting fixture. The choice between types of connections should be based on how you plan to furnish your home. If you want to keep the walls bare, go for the flush-mount option. They are the easiest to install and remove if you decide to change its content later on. The exposed type needs to be accessible for repair purposes though. The semi-flush type lies in between.
210-52 NEC Receptacle outlets in habitable rooms shall be positioned in such a way that no point along the floor line (measured horizontally) in any wall space is more than 6 feet from an outlet in that space. Each wall area of 2 feet or greater in width must have an outlet installed. The number of outlets in a room should be proportionate to the number of lights and appliances being plugged into them. For example, if six 100-watt lamps are plugged in, there should be six 100-watt receptacles.
As you can see, this depends on how many lights and appliances you have plugged in. If you have few light bulbs and small appliances like cell phones and cameras, then you can get by with just one 120-volt outlet for all your needs. But if you have several large appliances like heaters and air conditioners, you will need at least two 120-volt outlets for their power. And if you have lots of lights too, you will need at least three 120-volt outlets.
In conclusion, the necessary wiring requirements for outlets on walls depend on the size of the room as well as its contents. If you are not sure about the requirements for your specific situation, it's best to ask an electrician for advice.
How many electrical outlets should there be in a room? A bedroom should have one outlet for every 12 feet of wall space and at least one outlet on each wall, according to today's requirements. It's possible that this is an older structure that predates modern electrical requirements. If so, then assume there will be enough outlets.
A bathroom should have one electrical outlet for each fixture you plan to use. That's usually one outlet for the shower, one for the toilet, and sometimes another for a hand-held hair dryer or other small appliance. If these items require more than one outlet, then add them to your list.
If you want to be safe, though, you should also include a spare outlet just in case something goes wrong with one of the others. Spare outlets can be mounted in a cabinet or enclosed in a metal box on the floor or wall. They're usually available where cable TV enters from outside the house, such as at a front door or back patio door.
You should also check local regulations regarding electrical outlets. Some cities and counties may not allow you to install more than one electrical outlet in any given room unless it has a dedicated circuit breaker panel. If you know you'll be adding devices later that might require more outlets, make sure to ask about permit requirements before you start work.
A general rule of thumb is to have a maximum of 10 receptacle outlets per circuit and a minimum of one circuit every 500 square feet of floor space. The National Electrical Code requires that all cable connecting to a outlet be no more than 22 inches long. Any longer and there's a risk of electrical shock if you touch the cable while it's live.
You can install up to 100 outlets on a single 20-amp circuit. If you need to supply more than 100 devices, such as lamps, appliances, and equipment, you'll need additional circuits. Each additional circuit requires its own breaker or fuse block. You should also plan for enough power outlets to meet the needs of everyone who might want to use them at once.
People love to talk about the benefits of being wired for "surge protection". What they're really saying is that they don't want lightning to strike their house and set their electronics off. But unless you have a surge protector capable of handling a power surge from a storm channeling its energy through a nearby structure, your home wiring isn't going to save you. A surge protector will reduce but not eliminate the risk of damage to your belongings.
The best way to avoid having your outlets used beyond what you expect is to use only those devices that are needed at any given time.