I told him the address, then proceeded to the house with gas for the chainsaw. 

It might be able to be done without even losing a bedroom, but even if it goes from 4 bed 2 bath to a unit with 2/1 and a 1/1 unit, the rental income (or sale price) should be higher than a 4/2 SFR in the area.That said I'm not sure if there's something I may be overlooking.It already has 2 exterior doors positioned nicely with separate porches and room to have cars parked on different sides of the house (it's on a street corner).I looked up the zoning regs for how the plot is classified and it is allowed by right (don't need to apply special allowances or rezoning) to have multi-family housing on the plot.The rehab would already have it gutted enough that the changes to plumbing and electrical would be easier.I don't have any idea how hard it is to get separate metering for water/gas/electric. 

My apologies - I didn't mean to be so abrupt and short with my answer but honestly, the email you received just hit a chord with me.Imagine a gas station sending you an SMS telling you that they would no longer sell gas to you if you don't start driving more.

I kept pointing out to them that this isn't supposed to happen and there is obviously a leak somewhere. 

For feelings of dread I have also heard of that being a gas leak situation, so there are multiple options depending on what the tenant wants to do and what you are willing to do for them.

Those big windows in the shower are very poorly placed... they ALWAYS end up leaking at the sill creating all kinds of wet rot inside the wall, plus they're a privacy problem.We replaced them with a "gun slit" approx. 30"-48" wide and 6"-10" high, centered in the wall.

People expect a gas or charcoal grill too. 

Everything cost money in this business from gas to ink for your printer. 

If it's not from the ductwork it is likely a roof leak, but being that it is concentrated around the return that would be what I would look at first. 

Unless I'm mistaken there's nothing that would prevent you from buying a house with an oil tank that was leaking 25 gallons a day much less a decommissioned one.