Starting from scratch here. A transformer on the street, no buildings on the land yet.

I want to order temporary electrical service now, for use during construction. So we don't have to dig the street up twice, I want to have the wiring installed for the permanent service, too.

What should I ask for?

This is strictly residential.

EDIT I intend to use gas for domestic hot water, dryer, and range. Our summers are mild, so no air conditioning. I don't have any plans for any big loads, although I'd like to keep my options open.

  • What type of big load items (electric oven, jacuzzi, central air conditioning) are you planning to have in the house? – Jeff Widmer Nov 5 '10 at 11:27

Most houses have either 100 or 200 amp service. 200A service costs about 30% more, and I'd assume that cost is higher if you want to upgrade later.

What you need really depends on a few things, but the simple ones are: if you have electric heat or hot water, then go 200A. The other big loads are things like electric dryers, ovens, air conditioning, and hot tubs. Most of those are constant, but air conditioning power depends on the size of the house, and of course in general a bigger house will use more power (more lights and other electrical devices).

Here's a site to help determine the electrical service you need.

I would definitely install 200A service in a house >2000sqft, or if there was electric heat/hot water. If money was tight and none of those conditions are true, I might try to get by with 100A.

Right now I have gas hot water/heat, in a ~1500sqft house with A/C, and don't have any problems. I upgraded my panel from fuses to breakers, but still stuck with 100A because I just don't need more.

  • Cost will definitely be higher if you want to upgrade later -- the entire service will need to be re-run. – Mike Powell Nov 5 '10 at 13:20
  • To clarify, you're saying running the 200A service is 30% extra? How much extra (roughly) is the monthly payment for having 200A available? And is there a downside to having cables buried for 200A service, and only getting 100A over it (besides having paid too much for the wires)? – Steve Armstrong Nov 5 '10 at 14:16
  • 2
    I don't think there is any difference in the monthly payment, other than theoretically you can use much more electricity with 200A service. The only difference is the wiring, your breaker panel, and possibly the meter the electric company installs. If it's underground, you should at least put in wiring for 200A to the meter, as otherwise that would be by far the highest cost in upgrading (you'd probably end up paying as much or more than installing a totally new service). – gregmac Nov 5 '10 at 16:33
  • Unless the house is absolutely tiny, I'd go 200A. That said, I'm doing fine with 100A. Wishing it was 200A for the extra headroom, but I'm a pretty small consumer so it's working out OK. – Brian Knoblauch Nov 5 '10 at 18:44
  • I honestly can't remember the last time I saw a detached house w/ only 100 amp service. Maybe a mobile home? – kkeilman Nov 5 '10 at 20:48

As a homeowner, I'd go for 200A service, so that you don't have to re-run later if you get a big-use item like a hot-tub or something. It will cost a bit more up front, but it shouldn't cost you any more per month (you just pay for what you use), and it gives you plenty of headroom for anything you'd like to do later.


Without a building and a place for the perm service, I dont think you can have the wiring installed for both. I guess you could have them run the line for 200A service to the temp pole, and have it close enough to the final service entrance that you could disconnect it from the temp and move it over to the perm.

I take it the transformer is on the other side of the street? Another thing they might be able to do is lay both a temp and perm supply lines in the trench. Then leave the main perm supply disconnected at the transformer and lay it on the ground near where the perm service will be. The temp service supply line would be connected at first and then later abandoned.

  • Yes, the transformer is across the street. – Jay Bazuzi Nov 5 '10 at 23:37

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