How do I get my brother’s girlfriend to start paying for all the hot water she uses?

Dear Urban Diplomat,

My brother and I own a duplex together. The units aren’t separately metered, so we split all utility bills—water, gas and hydro. Four months ago, his girlfriend moved in and she’s a hot-water hog. Naturally, the utilities increased, especially with the recent spike in hydro bills. I proposed that we start splitting the costs into thirds, but my brother balked. How do I convince them to pony up?

—Wrong Division, Don Mills

Somehow, the adage “blood is thicker than water” seems less salient when that H2O is pouring down the drain. If your brother refuses to admit his ­lady love is driving up the bills, suggest having Toronto Hydro install independent meters for each unit (a.k.a. suite metering). If your households continue to grow—they have a kid, a partner of your own moves in—the split will stay fair. There’s a $600 Hydro fee for the service, plus another $400 or so for an electrician to install the system. But, considering those steep hydro bills, you’ll break even on the investment in no time.

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