Holm House 5 in Warsaw

installation of a 5000 l per day greywater-recycling-system (GWI 5.2-5.000)

The Holm House 5 project in Warsaw’s Mokotów district (developed by Skanska) is a prime example of how greywater-recycling has successfully transitioned from office buildings to high-end residential construction. Here, Skanska continues to implement the sustainability strategy it previously perfected in its flagship office towers.

Holm House 5 is particularly noteworthy because it demonstrates Skanska’s ability to scale technologies—once considered profitable only for massive office complexes (such as Edge Elbside or Centrum Południowe)—for the residential sector.

A New Standard for Residential Sustainability

Holm House 5 is part of a modern residential development and was among the first in Poland to receive the prestigious BREEAM certification for residential buildings. A central pillar of this recognition is its innovative water management system.

1. Greywater Recycling

While greywater systems in hotels or offices are often centralized, Holm House 5 utilizes an integrated solution designed to directly reduce operating costs for apartment owners.

• Functionality: Wastewater from showers and bathtubs is collected via a dedicated secondary drainage system.
• Treatment: In the building’s technical center, the greywater is filtered and biologically treated. The result is clear, odorless service water.
• Reuse: The recycled water is pumped back into the building to be used exclusively for toilet flushing in the apartments.
• Result: An average household at Holm House can reduce its potable water consumption by up to 30%.

2. Rainwater Harvesting

In addition to greywater recycling, Holm House 5 utilizes architectural features to support the “Sponge City” effect:

• Cisterns: Rainwater from roofs and balconies is stored in underground tanks.
• Irrigation: The park-like inner courtyards and communal gardens are irrigated exclusively with this harvested rainwater.
• Infiltration Surfaces: Specialized paving allows excess water to infiltrate the ground directly on-site, preventing the Warsaw sewage system from being overwhelmed during heavy rainfall.

3. Smart Home Solutions

Water management at Holm House 5 goes beyond treatment; every apartment is equipped with smart metering technology:

• Residents can monitor their water consumption in real-time via an app.
• The system detects unusual consumption patterns (e.g., a leaking faucet) and alerts owners before high costs or damages occur.

4. Certification and Benefits

Thanks to these systems, the building meets the stringent requirements for:

• BREEAM “Very Good”: A rating that remains rare in the Polish residential market.
• Reduced Utility Costs: By saving potable water and reducing sewage fees (as greywater remains in the loop), monthly costs for residents are noticeably lower.

Holm House 5 proves that ecological responsibility in residential construction is not a luxury, but an investment in the future viability of urban living spaces.

Realisation: 07/2024

Partner: Green Water Solutions

Investor: Skanska

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