400 amp service needs upgrade?

[magictolight.com]

I am working on a proposal for a new residential addition to a home which has a 400 amp service with a 400 amp 320 continuous meter socket feeding two 200 amp main breaker panels which are full. I have calculated the service demand at 357 amps. Will we have to change out this meter socket and install a ct cabinet and meter? Will we run into any problems adding one more 200 amp disconnect to this service to allow the addition of a new sub panel located at another location in the home? I have to set one more 200 amp panel because of the loads that we will be adding, indoor swimming pool, dehumidifying equipment and such.

 

[augie47]

O.H. service or UG lateral and who's responsible for the lateral would be two questions that arise here.
If the UG lateral and meter socket is POCO responsibility, then advise them of the added load and see what they say.
As far a the meter socket, I have seen them use 400s on that load and locally one POCO has a self-contained 600 amp, another would CT if they deemed the load required. Likely they may not be concerned about a 357 amp calculated load but the length of the lateral/drop may be an issue to them.
If the service conductors to the meter are your responsibility, you need to assure they are adequate for the load, if they belong to POCO, their responsibility,.

 

[Sierrasparky]

if the demand is under 400 what is the problem. Why can't you add a sub to the existing setup?