generator sizing

[arnettda]

When sizing a generator for the whole house. Optional stand by system.
Do I use the VA sg ft method as you would for sizing the service?
Or can I count the lighting fixtures and use there wattage and then use something per outlet?
What would I use for a VA ratting per outlet 180?
This is for an automatic transfer switch. When I use the VA per Sq ft it seems to be way more than the home draws.
Thanks

 

[bob]

Code in general says the generator should be sized for the load connected calculated from NEC section 220. If you have a 200 amp service, an inspector might require you to have a
48 kw generator. You may install an emergency panel with the loads that you need to be energized. This would allow for a much smaller generator. Check with the inspector and the Gen MFG for assistance.
This is a calculator to assist you with the load calculations http://www.kohlerpower.com/resident...=TC|16177|+generator++sizing||S|b|14488536570#