You might be able to get by with sub metering just the basement then deducting the basement usage from your utility meter readings. 

The amount of common area usage may be determined by actual measurement or, when such measurement is not possible, it may be determined not likely to exceed 1,752 kilowatt hours per year by a licensed tradesperson or a housing inspector.

When they break it's there problem not yours .Also, increase the rent by 30- 40 a month to compensate for water usage 

If gross, do you know what their usage will be? 

They will pay for the purchase, installation, usage and maintenance of the tub.

Eligible for multiple usages including STR. 10% CAP. - Triplex, Albany Oregon $505k with 3% seller concession: Turn-key, vacant, 2-2/1 + 1/1 with 10% no PMI investor program. - 6 Plex, Lincoln City Oregon $635k, mixture of units, seller preferred cash only, financed with local CU with 25% down.

The others would be limited for vacation rental usages by HOA's or local restrictions.

You might be able to reach out to your local power company and ask them for an energy usage report.

Water company will tell you if meter is/hass run constantly for x number of days. they should be able to tell you water usage compared to history for that building and compared to neighbors (make sure it’s same number of units.)In some areas they will send a team out to replace faucets, toilet valves and such to save water. 

The water usage is the same, the common electric/heat is the same, the licensing is the same, the trash refuse fee is the same, annual fire alarm certs are the same and labor to address tenant repairs should generally be the same.