Blu Roofs

A roof system designed to provide temporary or permanent water storage that gradually releases stored water - typically rainfall - over time.

Key Advantages of Blu Roofs


Manage stormwater runoff without occupying surface-level space


Well-suited for sites at which roofs make up a large fraction of the total
impervious area, and for sites with ground-level space constraints


Typically require no additional sewer connections besides the ones already
provided for the building 


Can cost less than other SMPs


Readily coupled with other SMPs, such as Green Roofs


Easy to install if structural and waterproofing requirements are met


Require no excavation


Can provide educational benefits, especially when used at public and/or highly
visible sites such as schools, recreation centers, libraries, etc. 

23% Project Cost Reduction

In 2010, New York City estimated that updating the city's stormwater system to control combined sewer overflows using Grey Infrustructure would cost approximately $6.8 billion over 20 years. By blending Grey and Blu-Green Systems, the city reduced its estimated cost by $1.5 billion.


$1.5 Billion Saved

Blu Roofs VS Smart Blu Roofs


Blu Roofs

Blu roofs or controlled-flow roof drain systems, are detention and retention stormwater management practices (SMPs) that provide temporary storage and slow release of rainwater on a rooftop. Blu roof systems are an effective practice for controlling runoff from buildings with flat or mildly sloped roof surfaces.


Smart Blu Roofs

On Smart Blu Roofs, water is detained on the roof surface more effectively. The release of detained and retained stormwater is precisely managed by a Smart Flow Control (SFC) and a Weather App. Smart roof drain valves (Smart Flow Control or SFC) operate entirely autonom, powered by solar/battery, and with emergency release. SFC is in applications around the world and have proven high reliability, fast payback, and low maintenance.

Similar Systems Provided:

Is A Blu Roof Good For My Project?

Expanding the footprint of existing structures or renovations often come with the desire to reduce the stormwater load of the sewer system, and simultaniously reduce city's service fees.

Such projects often have limited structural capacity and don't allow the installation of Green Roofs, Amenity Spaces, or Garden Decks.

Blu Roofs are considered as temporary load or live load and a perfect solution in such cases. Ideally, a Blu Roof can be an architectual design element creating unique perspective and can make a project stand out.


531 S. Water Street                     
Milwaukee, WI 53204