one water meter for two units

[Leonard Lee]

I have a house and garage apt on one water meter. The units have diff number of tenants. How do I split the h2o cost fairly ?

[Account Closed]

I work for a utility management company and there are various methods of way to "bill" residents for their usage. Common equations to determine billing that we use are as follows:

Ratio based on Square footage: = Bill total * (Unit Square Footage / Total Square footage)

Example: Unit 1 has 1000 Sqft, Unit 2 (garage) has 500 sqft. Water bill for the month is $100.
Unit 1: $100 * (1000 sqft /1500 sqft) = $66.67
Unit 2: $100 * (500 sqft/1500 sqft) = $33.33

Ratio based on Number of occupants: = Bill Total * (Number of Occupants in Unit / Total Number of Occupants)

Example: Unit 1 has 2 tenants, Unit 2 has 3 tenants. Water bill for the month is $100.
Unit 1: $100 * (2 tenants / 5 tenants) = $40.00
Unit 2: $100 * (3 tenants / 5 tenants) = $60.00

Ratio based on half square footage, half occupants (50/50 method): = (Utility bill * 1/2)*( Unit Tenants / Total Tenants) + (Utility Bill * 1/2)*(Unit Sqft / Total Sqft)

Example: Unit 1 has 2 tenants, 1000 sqft. Unit 2 has 3 tenants, 500 sqft. Water bill for the month is $100.
Unit 1: ($100 * 1/2) * (2 tenants / 5 tenants) + ($100 * 1/2) * (1000 sqft / 1500 sqft) = $63.33
Unit 2: ($100 * 1/2) * (3 tenants / 5 tenants) + ($100 * 1/2) * (500 sqft / 1500 sqft) = $36.67

This method is much more complex to do, but a simple Excel spreadsheet can help alleviate the headache of doing this monthly.

Because of the situation, and a majority of the time with a single family residence (even with a garage apartment) the utility company won't install a second meter to service your property. Some other options that you could have is to install a water sub-meter system. These could be quite pricey, and are more common for larger multi-family units with one meter servicing an entire building. With a sub-meter ( a meter you install on the property side of the water meter) you can track usage of each unit, and know exactly how to bill a property.