There is no international standard. State and local codes may vary. Refer to Some typical recommendation about receptacles installation as followings:
1. Receptacles must be located so that no point on the wall is more than 1.8 m horizontally from a receptacle measured along the floor line. This means that the distance between receptacles along a continuous wall must not exceed 3.6 m. Do not count wall space occupied by:
a) doorways and the area occupied by doors when fully opened;
b) windows which extend to the floor; and
c) other permanent installations that would limit the use of the wall space (e.g. fireplaces, clothes closets, etc.).
These receptacles are normally installed 300 - 400 mm above the floor.
2. All 15 amp and 20 amp receptacles must be the tamper-resistant type unless they are dedicated for microwaves, refrigerators, freezers or kitchen counters or located in attics or crawlspaces.
3. A switch controlling a receptacle or lighting fixture must be installed for every room. If only one half of a duplex receptacle is switched, it will also qualify as one of the receptacles required in item 1.
4. The maximum over-current device permitted for lights and receptacles is 15 amperes (fuse or circuit breaker) and a maximum of 12 outlets (lights and receptacles) may be connected to each 15 ampere branch circuit.
5. Circuits supplying receptacles in sleeping rooms must be protected by an arc-fault circuit interrupter (AFCI). An AFCI is a device intended to provide protection from the effects of arc-faults by de-energizing the circuit when an arc-fault is detected.
6. At least one branch circuit must be provided solely for each receptacle installed to supply power to a central vacuum system.
7. At least one branch circuit must be provided solely for each receptacle installed to supply power to a sump pump.
For Bathrooms and Washrooms:
a) Ground fault circuit interrupter protection must be provided for any receptacle located within 1.5 m of a wash basin, bathtub or shower stall.
b) Bathrooms and washrooms must have a receptacle installed within 1 m of the wash basin.
c) Receptacles and switches installed in bathrooms must
a) Kitchen counter receptacles must be located on the wall behind the counter work surface so that no point along the wall is more than 900 mm from a receptacle. This generally requires that receptacles be spaced 1.8 m apart.
b) Sinks, built-in equipment, and isolated work surfaces less than 300 mm long at the wall, need not be included when calculating the spacing of counter receptacles.
c) At least one receptacle shall be provided at each permanently fixed island counter and at each peninsular counter space, that is 300 mm x 600 mm or larger.
e) A receptacle must be installed for a refrigerator and must be supplied by a branch circuit that does not supply any other outlets except that of a recessed clock receptacle.
f) Receptacles installed within 1.5 m of sinks shall be protected by a ground fault circuit interrupter.
a) All receptacles located outdoors and within 2.5 m of ground or grade level must be protected by a ground fault circuit interrupter (GFCI) of the Class A type.
b) At least one receptacle, supplied by a separate branch circuit, must be provided outdoors for the use of electrical appliances.
c) At least one receptacle, supplied by a separate branch circuit, shall be provided for each driveway.
d) At least one receptacle, supplied by a separate branch circuit, must be provided for each car space in a garage or carport. Garage/carport light fixtures and a garage door opener may also be connected to this circuit.
Also teach children not to touch electric cords and outlets. Install protective covers on all electrical outlets; preferably the type with shutters that require insertion into both holes simultaneously. Block wall outlets with furniture if possible, use ground-fault circuit interrupter (GFCI) outlets in the bathroom, kitchen and yard. Replace frayed wires and keep electrical cords out of reach. Prevent children from swimming or paying outside during electrical storms and supervise children when they play with toys that run on electricity.