What is a Sufficient Number of Receptacles? A historical review.

There are code provisions that determine what the minimum spacing of receptacles needed. We refer to this as the “6 and 12 rule”. Where there will be no space greater than 6 feet from a receptacle measured horizontally. There should be at least one receptacle on any wall space that is 2 feet or greater. This requirement applies to habitable rooms (Habitable: any room used or intended to be used for sleeping, cooking, living or eating purposes.) Note that the NEC does not define “Habitable Rooms” but does reference the term in the code.

Let us get started, in 1923 convenience outlets first appear NEC section 1404: "Receptacles for attachment plugs (convenience outlets) are strongly recommended in order to facilitate the use of electrical appliances which, otherwise, must be connected to sockets designed primarily only as lamp holders."  I can’t help but always think of “A Christmas Story” when the “Old Man Parker” is trying to light up the Christmas tree and sparks are a flying.

The 1933, NEC section 2012, The following was  recommended  for all single family dwelling having provisions for cooking (electrically or otherwise) that have a total floor area for a single family of more than 400 square feet square feet.  Every kitchen, dining room, breakfast room, living room, parlor, library, den, sunroom, recreation room, and bedroom should have a sufficient number of receptacle outlets that no point on the wall be more than 15 feet distance from such outlet. At least one receptacle outlet to be installed near to each permanently installed laundry tub or set if such tubs.

In 1935 the recommendation was slightly modified and it was “required”  in NEC section 2010 to have at least one receptacle outlet in each 500 square foot floor area.

Now in 1937 per NEC section 2010 it was now “required” that there could be no more than 10 feet of wall space from a receptacle in every kitchen, dining room, breakfast room, living room, parlor, library, den, sunroom, recreation room, and bedroom. At least one receptacle outlet to be installed near to each permanently installed laundry tub or set if such tubs.

 

Then in 1940 NEC section 2110 the requirement was changed to one receptacle per every 20 feet or major fraction thereof  of a total distance around the room as measured horizontally along the wall  at the floor line. In 1947 a receptacle in the floor that was not close to the wall would not count towards this requirement.

1968 brought a new term “Family Room” which was added to the listed rooms types.

 

In 1971 it required at least one receptacle installed outdoors, adjacent to a bathroom basin, and in each basement, attached garage as well as fixed room dividers.

Here comes the 1990’s and with it the explosion of kitchen appliances.  In 1990 NEC Section 210-52 (C) Counter Tops; “In kitchen areas and dining areas of dwelling units a receptacle outlet shall be installed at each counter space wider than 12 inches.  Receptacles shall be installed so that no point along the wall line is more than 24 inches, measured horizontally from a receptacle outlet in that space. Island and peninsular counter tops 12 inches or wider shall have at least one receptacle for each four feet of counter top. Counter top spaces separated by range tops, refrigerators, or sinks shall be considered as separate counter top spaces.”

 

There are more minor tweaks in the following code cycles but this does get us to what our modern requirements are.