Water efficiency requirements for new constructions (and major rehabilitations) in Portugal are established by the Water Efficiency Regulation (REH), which is the primary legal instrument that implements these obligations. The REH imposes the installation and compliance with specific performance targets, aiming to reduce water consumption. Here are the essential technical requirements:
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Mandatory Technical Requirements (REH Decree-Law):
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Faucets and Showers: Installation of reduced flow devices (for example, aerators and flow limiters) is mandatory. The REH establishes specific targets, such as a maximum flow of < 9 liters/minute for showers and lavatory faucets.
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Toilets: Installation of dual-flush toilets (for example, 3/6 liters) is mandatory, which allow choosing the volume of water to use, reducing consumption per flush.
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Water Recovery Systems:
- Rainwater and Gray Water: In large buildings (high coverage area or high consumption) or in areas with specific municipal regulations, it may be mandatory to install rainwater or gray water (from showers and lavatories) recovery systems for non-potable purposes, such as irrigation and toilets.
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Support Programs:
- The implementation of water efficiency measures is complemented by financial incentive programs, such as the Support Program for More Sustainable Buildings, which offers subsidies for the acquisition and installation of high-efficiency equipment.