Keep in mind that you do not have to supply service to equal all the breakers that are installed in your panel. You can size your panel based upon connected load, and you can make some assumptions based upon the profile of the equipment or actually survey the actual use. You could for example assume that the electric furnace and the air conditioner would never run at the same time and you would not need to size the panel for both loads. The more retentive you get about circuiting a house or shop, the greater the diversity factor and the more you can undersize the service without affecting reliability. If you were to check my breaker panel you would find over 400 amps of branch circuit breakers installed in a 200 amp service, but the peak load of my panel seldom is over 100 amps! I have many lighting circuits and general purpose circuits that have little or no load on them. I would get an electrician that is willing to analyze your loads properly before shelling out big bucks for a service that is way too big. To give you an idea, I feed a 3600 sqft house and over 1800 sqft of air conditioned shop with welder, Air compressor, and all the normal tools that are associated with such a shop and feed the entire setup with a single 200 amp service! I do have natural gas for all water heaters, furnace and dryer, but this is still a lot of circuits.
Regards, John McGraw
