Commercial building load estimates

[amcengineers]

I work for a small MEP firm that mainly does tenant finish out work and remodels and electrical loads are straight foward to calculate for these. In the future we have several shell building designs that we will be doing, retail, office, and light industrial. Many of the shell MEP plans I see have a kva load estimate per sq-ft based on the occupancy to size the service, but these numbers are all over the place. As most times the tenants are unknown I need some type of reference. I have some numbers that I use as reference based on how I was taught but I am looking for some type of reference manual. Does IEEE or some other organization provide this type of information or does anyone have a good reference book to recommend. I can do estimates by making certain assumptions, but looking for something more definitive.

 

[davidbeach]

What does the electrical engineer on the project have to offer for advice? Or is he too busy designing the HVAC system while you ponder the electrical loads?

 

[lansford]

I understand your frustration.
In the past we were able to locate a key person with the local utility who had a lot of this information at hand.
The trick is to find the "correct" person.
JIM

 

[ykee]

Calculate as a standard office building to determine the service size to the shell. If a tenant needs a significant upgrade because they are say a computer training centre, then they will need to pay for that under their TI's. An oversized service is of little value to most building owners, unless they are targeting a specific type of occupancy. If the owner is targeting a known audience for their building, then calculate the load accordingly.

As for specific W/ft2 to use, check your local electrical code, it will provide guidance and various min/max values.....something which I'm sure the electrical engineer sealing the drawings will be familiar with.