Metering of Water Charges in Apartment Complexes: Sub‐Metering and RUBS

by Venkat

The increasing demand for water and the general understanding that water is becoming scarce have resulted in a competition among the water users. One of the most serious issues of water management is the question how to allocate the water resources to guarantee sufficient amount of water for all demands. That is why, it can be expected that allocation management will gain further importance in the future. It is not exaggerated to declare that “the issue of allocation overshadows all other aspects of water management”.

This article tries to create an awareness as to various possible methods that the water can be conserved, where there is a single master water meter from the utility supplier ( Ex : BWSSB, in Bangalore) , or the water is purchased through tankers or extracted from bore-wells within the site.

Why do we need to start thinking on Conservation, Allocation, Sub-metering, there are many reason, here is some of them (from BWSSB) for the residents of Bangalore

1. Primary source for water for BWSSB is Cauvery
2. Cauvery can support BWSSB’s expansion plans till 2012 only, beyond which there simply is no water available
3. Currently BWSSB caters to around 60% of the city’s demand of 1500 MLD, the rest being groundwater (via bore-well, tanker)
4. Groundwater levels of Bangalore are fast depleting

These reasons are good enough to start thinking about conservation.

Conservation : Three key things that come to mind when we talk about conservation are

1. Rain Water Harvesting
2. Recycling of waste water
3. Controlled usage of water through paying as much as use (sub-metering or bill division)

Rain Water Harvesting

Rainwater harvesting is the accumulating and storing, of rainwater. It has been used to provide drinking water, water for livestock, and water for irrigation or to refill aquifers in a process called groundwater recharge. Rainwater collected from the roofs of houses, tents and local institutions, or from specially prepared areas of ground, can make an important contribution to drinking water. In some cases, rainwater may be the only available, or economical, water source. Rainwater systems are simple to construct from inexpensive local materials, and are potentially successful in most habitable locations.

Recycling of waste water

There are two types of waste water Grey water & Black Water. Greywater is wastewater generated from domestic activities such as laundry, dishwashing, and bathing which can be recycled on-site for uses such as landscape irrigation and constructed wetlands. Greywater differs from water from the toilets which is designated sewage or blackwater to indicate it contains human waste. Greywater composes 50–80% of residential wastewater generated from all of the house’s sanitation equipment (except toilets).There are many vendors in the market which provide solutions in this area.

Controlled Usage

There are other options which also help conservation such as “Controlled Usage” and is not much explored area by the residents and association. This approach promotes conservation by controlling the usage. Studies have been done in other countries to better understand how billing methods affect water consumption patterns, it is found

1. That the residents who pay for their water use less
2. Billing type is a more important influence on consumption patterns than either the cost of water/sewer or the age of the building.
3. There are two main methods of allocating the charges to the residents

a. Sub –Metering

Sub-Metering : Sub-metering a master-metered building is unlike virtually any other energy conservation measure that can be undertaken by a building owner. Sub-metering as a conservation measure enlists both management/association and residents in the effort and generally produces a conservation savings of 20 to 40%. With advancements made over the past years, there now exists a wide range of technologies available to accomplish sub-metering for water, gas or electric for almost every property configuration. A typical sub-metering system consists of a meter to measure usage of a specific utility for each unit and a wireless system to transmit the data to a central computer to allow for remote reading. A third party billing company is normally used to read the meter data and format a bill that is sent to the tenants.

Through Sub-metering:

* Residents Pay for Actual Usage
* Reduce utility usage 20% – 40%
* Less legal complication
* Enhances property value

RUBS (Ratio Utility Billing System) : RUBS is a method of allocating water and sewer costs in apartments, condominiums, offices, shopping centers and other multi-housing communities. The actual utility bill for the property is distributed to each resident based on an allocation formula. Factors in the formula can include one or a combination of the following:

* Number of occupants
* Square footage
* Number of bathrooms
* Number of water fixtures

Through RUBS

* Allocation is Consistency
* Cost – Little or no upfront investment
* 15% to 20% reduction in usage
* May be implemented where Sub-metering is difficult
* Excellent means of starting program

RUBS Vs Sub-metered

Advances in metering technology have made it possible to economically convert multi-unit properties to individual metered service using sub-meters. However, the plumbing configuration in many properties makes it too costly, and in some cases, impossible to install individual sub-meters. RUBS is a way to help residents understand the true cost of utility service in properties where meters cannot be feasibly installed. By allocating a portion of the property utility costs, residents can see the connection between usage and cost. By separating utility costs from rent, water conservation is encouraged. This helps keep resident total housing cost as low as possible and also promotes environmental conservation.

For more details regarding RUBS and Sub-metering, please feel free to contact

Note: This Article has been contributed to ADDA by AnCenergy Technologies Services Pvt Ltd.

AnCenergy has more than 16 years’ of experience in United States providing solutions for Sub-metering and RUBS, in addition to other Energy Management Services In India , starting with Bangalore, AnCenergy wants to create awareness and also help in providing solution for Sub-metering , RUBS and also provide consultancy for Rain water Harvesting and Waste water recycling. AnCenergy also provides solutions for managing the billing of Common Area Expenses ( both utility and non-utility) for apartments, condominiums, offices, shopping centers and other multi-housing communities.

Contact Information: Vinod Damodaran | AnCenergy Technology Service | Bangalore | Mob : 89040 68003 | Land : 080 41642282
Website :

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