Replies

1. 
   Danno | Jul 17, 2006 03:32am | #1

   I'm no electrician, but I belief the numbers are in terms of lineal feet of wall. If you can figure the lineal feet of all your walls added together and divide by the number of feet between outlets you'd get a ballpark figure. I also think that walls that are less in length than the number needed between outlets also have to have one. And, I think kitchens may require outlets closer spaced than in the rest of the house. I suppose one you have figured a couple houses that way, you could calculate what that comes out to per squre foot, but I don't know how useful the number would be. Would probably depend on how open a floor plan each house has.

   I just got out my code book (Michigan) and it has outlets spaced "so that no point along the floor line in any wall space is more than six feet, measured horizontally, from an outlet in that space. Recpetacles shall, insofar as practical, be spaced equal distances apart." Basically, that means receptacles 12 feet apart.

   
   

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   Edited 7/16/2006 8:46 pm ET by Danno

2. 
   BarryO | Jul 17, 2006 03:36am | #2

   There are standards for # receptacles per square foot in commercial buildings, but not residential.  There are other standards for residences, which includes the maximum distance along walls to a receptacle in many rooms, as noted by the other responder.

1. 
   MrBill | Jul 17, 2006 04:26am | #3

   STream,

    The other thing to do is imagine yourself living in the house and think about where you would like to have receptacles. Our present house meets code, but for instance, there is a landing a the top of the stairs that does not have a receptacle which would be nice for the vacuum. Also, I would personally want an outside receptacle on all four sides of the house.  Look at placement in the bedrooms too. Having receptacles is one thing, but if they are located on the wall where the dresser will be, they are pretty much useless because they will be hidden. Etc Etc. I am sure others will have suggestions. Bill Koustenis

   Advanced Automotive Machine

   Waldorf Md

3. 
   Danno | Jul 17, 2006 01:58pm | #4

   I re-read your post and see that you are building your own house--or having it built. Isn't there an electrical plan--floor plan with all the lights and switches and outlets, etc. marked out on it? That would be the way to go, then the electrician can just take off from the plan and give you an estimate, and you will know where everything is going and can make changes on paper--lots cheaper than changing things in the actual house!

4. 
   JonE | Jul 17, 2006 02:10pm | #5

   There's no number on receptacles per SF.  It's based on the maximum distance from any receptacle.  A well-thought-out electrical plan will be the best help to determine your costs, because I know a lot of electrical contractors price jobs by the box.

   FWIW, I have 100 receptacles in my new house, including the basement so far.  There will probably be another 12-15 when the basement is finished.  4300 square feet including the basement, so that's about 3 per 100 sf.  But you really need to look at it in terms of code.  A house with smaller rooms and a lot of short walls will have many more outlets than an open floor plan with large spaces.   I built a timber frame, so my outlet count is probably low.  I put them in some strange places just to get outlets near where I needed them.   A large 2-story colonial with separate living/dining/kitchen spaces and no open loft space could probably double my number for the same SF.

   Two places I have found them to be exceptionally convenient - as another poster said, top and bottom of stairs and at each stair landing.  Also, I tried to place an outlet directly underneath every wall switch for a room, at standard height.  Usually a wall switch is not blocked by furniture so it will always be a convenient place to plug something in like a vacuum.

    

1. 
   junkhound | Jul 17, 2006 04:24pm | #6

   FWIW, I have 100 receptacles ....

   Agree, A person cannot have too many outlets.

   Go with spec grade also, as they hold the plugs much better.

   On own house tried to have less than 4 ft from any outlet, also have about 10 ea 12 outlet plugmold strips in garage and shop, never too many. MBR also has a plugmold strip on the back of the bed (clocks, radios, lamps, elec blankets, toys.....). Computer areas have about 10 outlets plus a couple of plug strips......  

   Started to try to count, 22 dual outlets on 4 different circuits in the kitchen alone (about 300 sq ft) = about 7 outlets per 100 sq feet. (or, 14 plug in spaces per 100 sq ft.

   The garage/shop where I do most of the mechanical work is about 500 sq feet with over 15 dual  outlets and 5 plugmold strips, over 18 plug-in spots per 100 sq ft.

   BTW, if you are not planning that way already, have your lights on separate breakers form outlets.

1. 
   BarbaraD | Jul 26, 2006 08:44am | #12

   "BTW, if you are not planning that way already, have your lights on separate breakers form outlets."

   I'm wondering why. 

1. 
   Jer | Jul 26, 2006 01:57pm | #13

   So when one trips you have light or power for light to fix the problem.  If you can it's always best to categorize your circuits.  The kitchen, the bathroom, the LR etc.  Also lighting is usually put on a 15A and many or most outlets in new work anymore are run in 20A. 

2. 
   pickings | Jul 26, 2006 05:20pm | #14

   "BTW, if you are not planning that way already, have your lights on separate breakers form outlets."

   I'm wondering why. 

   I think it's code now.....but makes sence, as stated above.

1. 
   cap | Jul 26, 2006 08:10pm | #15

   No, it's not an NEC (or other national Code requirement) to put general lighting outlets on separate circuits than convenience receptacle outlets. 

   For certain areas like kitchen counters, laundry, and others, the receptacle circuits cannot have lighting on them.

   In a properly designed system that combines lights and plugs on a circuit, you're not likely to have breakers trip.  Granted, if someone overloads a circuit, it'll happen.  If a house has central heat and air, it's not likely that a convenience receptacle/lighting circuit will ever be overloaded; the most common reason for overload is plug-in space heaters.  The trend is towards appliances that use less power, so how could someone overload a bedroom circuit, if it's properly designed?

    I wire lights and plugs on the same circuit where cost is the primary consideration; it takes less cable, and less time to install, circuits that combine lighting outlets and general convenience receptacle outlets.

   Cliff

5. 
   WayneL5 | Jul 19, 2006 04:53am | #7

   I agree with Danno.  You should have an electrical plan and have the contractor quote on that.  The more stuff you make up as you go along the more expensive and less functional the home will be.

6. 
   ncarey | Jul 26, 2006 03:32am | #8

   The NEC's general requirement (there are special requirements for bathrooms, kitchens, etc.) is that

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   No uninterrupted stretch of wall may be more than 6 feet from an electric
   outlet — ergo, outlets can be at most can be 12 feet apart. Any stretch
   of wall two feet long or longer must have an electric outlet.

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   My own thoughts are that, on top of the minimum requirements,

   1. You can never have too many electric outlets.
   2. There should be an electric outlet at each corner of a room.
   3. There should be an electric outlet at each window in a room. Depending on context, you might prefer to place the outlet to the side of the window, in which case, put an outlet to either side of the window.
   4. Bedrooms should have at least one outlet at each side of the head of the bed.
   5. No outlet should be more than 6 feet from the next.

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7. 
   TLE | Jul 26, 2006 03:41am | #9

   Again, you can't have too many outlets.

   I also like to put two gang boxes in locations that seem to always require more outlets than available. Like behind the TV/ entertainment center, in the bedrooms in the general area of a night stand, near the largest piece of countertop in the kitchen, work bench areas, and so on.

   Don't just put in the code minimum number of outlets.

   Terry

1. 
   BryanSayer | Jul 26, 2006 06:59am | #11

   I was going to mention the double duplexes near the bed also. A pair on either side. Between the lamps, clocks, electric blanket, etc. it is most useful.

8. 
   Jer | Jul 26, 2006 04:19am | #10

   Outlets run every 12' in a room.  You can do more, but I think that's minimum.