Service in a 27,000 square-foot mansion

[jeff48356]

I'm watching a documentary on TV that shows all these huge mansions, and one in particular is a 27,000 SF mansion with 10 bedrooms, 14 bathrooms, and a bunch of other stuff that no ordinary house would have. I was just thinking, how would you wire something like that?

What kind of service would such a house have? How many amps total? I know that residential panels come in 200A max, and I imagine that just one would not be nearly enough. What size main service conductors would they have to use? I imagine that they would have to use a wireway at the point of entrance, with taps of 4/0 AL conductors leading to each 200A panel.

Have any of you ever wired a mansion like this? How much did the entire job cost the owner?

 

[Dennis Alwon]

It would depend on the load. Many houses today use all LED and very efficient a/c units and appliances. If the heat is electric strip heat then the load will be high but I could see a 600 or 800 amp service working -- I can also see a 1200 amp service needed. I am doing a 12,000 sq. ft house now and a 400 amp service is more than adequate

 

[John120/240]

What Dennis said. Here a 12,00 sq ft home with gas heat had a 400 A service. Two 200A panels in the basement & a sub panel on the first & second floors.
5,000 sq ft home with electric heat required Two 400A services side by side. Plus the 5,000 sq ft one had electric heated hot water heat in the basement floor.

 

[elf friend]

I wired a house a couple years ago that was about 12000 square feet with an eight car attatched garage (four above and four below). The house had all in floor heating with electric stove, dryer, and water heater. Installed a Seimens 400 amp three wire panel that had 46 slots. I did need to add a 40 slot sub panel but only because I like to put each bedroom on its' own circuit and there where about 10 20 amp circuits in the kitchen.
I have installed a 400 amp service on numerous houses that have geo therm heat with the resitive back-up heating as these require almost 200 amps by themselfes.