so it's a house that's split up into suites, i'm guessing? i had more of an apartment building scenario in mind.
sorry if i wasn't clear. what i meant about "included" and the "power company not caring" was with the assumption that you didn't have a "friendly" landlord. what i mean is, IF you were in an apartment block, say, and the power was included in your rent, the heatiness from high power consumption would shift from you to the landlord, BUT, your landlord might notice pretty quick when your powerbill starts hemorrhaging money. on the other hand, if you pay for your own power (AND it's in your name), your landlord might not come knocking because of your power bill but the power company might (depending where you are and how cooperative they are with the local law enforcement blahblahblah).
either way, the point is moot (and thanks for clarifying).
and i'm not familiar with the cannabis laws in the uk...... if there is an iota of a chance (legally) that the owner can lose the house over a grow, i would strongly suggest against a high power op.