We are currently doing a tenant improvement project on a building that has a central core of bathrooms that does not use any water saving fixtures. The tenant improvement space will be adding two new restrooms that will use water saving fixtures. These two new restrooms will not meet the code requirement for total fixtures required and as such the central core restrooms will need to be used by the occupants. The requirement for Water Efficiency Credit 1.1, LEED for Commercial Interiors, states "Based on tenant occupancy requirements, employ strategies that in aggregate use 20% less water ". Under Frequently Asked Questions it is stated "Water Efficiency credit 1 is based on the planed occupancy of the space, regardless of when the restrooms are constructed, who pays for them or where they happen to be located." Since the tenant improvement space does not provide enough restroom fixtures and the occupants will need to use the central core restrooms, will the central core fixtures need to be upgraded to get the water reduction credit 1.1? Our interpretation is the central core does not need to be upgraded as this tenant improvement project only has control over the new fixtures.
LEED for Commercial Interiors, Water Efficiency Credit 1.1, requires that the design case achieve a 20% reduction in aggregate water use from the calculated baseline for the tenant space. The calculations of this credit need to include all fixtures necessary to meet the needs of the occupants. The baseline calculation is dependent on fixtures meeting the Energy Policy Act 1992 standards; however, the design case calculation demonstrates actual or predicted water use and might be achieved using strategies exclusive of upgrading the central core fixtures. The project team should first establish the water use baseline by including all fixtures to be used by tenants, including the central core restrooms, using the EPAct 1992 values. The design case calculation will be based upon real values, enabling the project team to determine the water volume that must be reduced to satisfy the credit. Once the water volume is determined, the project team can then decide how to achieve the necessary percent water use reduction. Applicable Internationally.