I am currently building a detached 250 sq feet studio in my backyard. The studio will have a tiny bathroom with a tankless water heater, a baseboard heater, and a few lights, a mini split (ac), of course a few plugs and switches. The electrical will come from the main box on our house. The current box is rated 150 Amps. We will get a service upgrade to 200 amps, a new 200 amp box and a sub panel of 100 amp. The sub panel will feed the studio. Here are the specs if what will ge in the studio: Tankless water heater, 60 amps, 240v Baseboard heater 20 amps, Mini split 20 amps, 220v Lights, switches, Potientially a ceiling fan
The question is, if i currently have 150amps, will the service upgrade to 200 amps with a 100 amp sub panel be sufficient to feed the right power the studio?
I appreciate your insights.