Not strictly DIY, but anyway....

A friend of mine has an office, in that office there is quite a lot of
halogen lighting, and probably 20 PCs, and 4 servers.
They are soon to get aircon in the "Computer Room" (Basement!)
The electricity meter is rated at only 40A (Single Phase) - The little disk
inside is spinning at quite a high rate! (I think it was about twice per
second, or thereabouts when I looked)
They seem to have two consumer units, each about 20 way - both have a 100A
isolator
I have a clamp meter, so will test the load on it when I am next there.
Should this be uprated, as I know my house supply is 80A!
Would this usually be done free of charge by the electricity company?

I was also going to suggest looking into getting Economy 7, so the
electricity used at night (Servers and A/C and people who leave their PC's
on!) would be on cheaper electricity.

Sparks...