Testing Electrical Capacity of New Offices?

An anonymous reader asks: "Running a small graphic design studio, we've hit a snag that I'm sure many tech-reliant small businesses have hit before: our small flock of file servers, multi-processor machines and 22" monitors draws more electricity then the wiring in our current space can take. We're looking for a new space for this and other reasons, and as we look around we're generally forced to take the word of landlords as to what sort of amperage an electrical system can provide. Does anyone in the Slashdot community know a reliable way to test and see if an electrical system can support the needs of a computer-reliant business?"