Blue-Green roofs for future-proof cities.
Multifuntional roof systems allow people to live in a healthy environment, while enjoying the ecological and economic benefits of blue-green infrastructure.
Solution
From grey to healthy green.
Space for green infrastructure is disappearing in ever denser cities all around the world. Yet, cities feature vast areas of unused and unexploited rooftops. These empty spaces can be reclaimed for stormwater management in combination with plant growth by creating blue-green roofs and roof gardens.
Rooftops can be transformed into functional landscapes or roofscapes, designed to conserve and generate energy, manage rainwater, create space for biodiversity and space for people to enjoy or any smart combination thereof.
With this approach, roofs are no longer just there to keep out the rain. They become an integral and functional part of the building they are on and the city they are in. A transformation from unexploited capital to functional space.
Process
How does it work?
In order to deliver ecosystem functionality, vegetated roofsystems need water. Too often water is missing in conventional green roofs during prolonged dry spells in summer; exactly when the urban cooling capacity of vegetated roofs is needed most. Based on scientific peer reviewed research by KWR Water Research Institute we have evolved the conventional green roof to a naturally functioning blue-green roof. By incorporating significant stormwater retention volume and capillary functioning in the design, full smart water management is now possible. Improving ecosystem functionality in water sensitive design.
System functionality
The hollow Permavoid subbase makes it possible to store more rainwater in lightweight geocellular units underneath the soil in podium decks, blue-green roof systems and roof gardens. This stored rainwater is made available to the plants by capillary rise through capillary fibre columns in the Permavoid units. This nature- based solution of capillary irrigation eliminates the need for drip lines, valves, hoses, pumps and the associated maintenance requirements. Water is available for the plants when they need it, naturally, on-demand, and most importantly without the use of energy; just like in nature.
Water is the key to successful green infrastructure at any level, in every green design. Keep rainwater out of the sewer and put it to work to support, biodiversity and help cool the urban environment.
Benefits
Strong benefits for rooftops.
Water is available for the plants when they need it, naturally, on-demand and most importantly without the use of energy. Just like in nature.
Irrigation water savings
The total amount of water needed for irrigation can be reduced without hampering plant growth, because capillary irrigation does not experience surface evaporation losses. Independent research by STRI in Australia, the UK and the Gulf region showed irrigation savings up to 60%.
Versatile mounting platform
A reliable connection to attach complementary elements to the Permavoid capillary system is available with the addition of the PermaLock in which bolts can be screwed. No more drilling into the roof to attach fencing, solar panel systems or wooden decks.
Plant growth & biodiversity
The reliable capillary availability of water for vegetation enables the landscape architect to choose from a wider array of plant species. Permavoid Project Smartroof 2.0 in Amsterdam scored highest on flower count and bee-species diversity in an ecological study including 21 different green roofs and roof gardens in the summer of 2018 and 2019.
Cooling down
Stored water can be used for a myriad of functions, from drinking water generation to flushing toilets and grass irrigation or synthetic turf cooling, conserving water, keeping water out of overloaded sewer systems during peak events and at the same time creating a valuable urban cooling effect.
Water is key to successful green infrastructure in every design. Keep rainwater out of the sewer and put it to work to improve city life.
Systems
Solutions for every rooftop.
Water availability is the key of successful multifunctional blue-green roofs. Because without water, functional performance of this urban green space grinds to a halt. The Permavoid capillary system can be set to retain any amount of rainwater from 20 up to 300 mm, which in a temperate climate suffices for a long period of unrestricted plantgrowth without supplemental irrigation. Capillary irrigation creates a stable soil moisture content. Therefore, the designer is no longer restricted to just sedum or drought tolerant species. It's possible to create an annual or perennial species composition from seeds, even in limited soil depths on the Permavoid capillary subbase.
Water availability is the key of successful multifunctional blue-green roofs. Because without water, functional performance of this urban green space grinds to a halt. The Permavoid capillary system can be set to retain any amount of rainwater from 20 up to 300 mm, which in a temperate climate suffices for a long period of unrestricted plantgrowth without supplemental irrigation. Capillary irrigation creates a stable soil moisture content. Therefore, the designer is no longer restricted to just sedum or drought tolerant species. It's possible to create an annual or perennial species composition from seeds, even in limited soil depths on the Permavoid capillary subbase.
Though our aim is to store and reuse rainwater on roofs, every now and then it's impossible to do so due to for example the limited load-bearing capacity or slope of a specific roof. We believe a green roof, with limited waterstorage capacity is better than a grey roof, collecting heat during hot summer days. Therefore Permavoid offers a range of products that can be used under a mixed Sedum (succulent) vegetation in a light set up with shallow soil.
Ask for the Permavoid basic product line and learn about your options.
The high loadbearing capacity of the Permavoid subbase facilitates not only the formation of vegetated roof systems but paved parking decks or access roads also. Combining the functions of stormwater management and traffic saves space and manages rainwater at source, preventing overloaded sewer systems.
Conventional end-of-line solutions are converted to Source-Control designs. Combined with oil absorption and natural bacterial treatment in the Permafilter geotextile the system not only reduces water quantities, but also to improved water quality in SuDS designs.
The Permavoid lightweight system makes it a superb subbase beneath sports facilities on rooftops or podium decks. Roofs often have a limited load bearing capacity, using crushed stone for subbase drainage is often impossible or impractical in these locations in these applications. Most surfacing types of sports can be used atop Permavoid including amongst others natural grass and synthetic turf. Running track surfacing or fall arrest safety surfacing used around playground equipment for children and athletes can also be used.
Sports with a view.
Inspiring projects
Get inspired by these projects.
From small scale private rooftop gardens to parks on top of a trainstation; we are proud of the projects we have realized with our partners throughout the years.
Have a look at a selection of the Permavoid multifunctional rooftop projects installed globally and learn more about the technology in our rooftop brochure.
TKI Project Mannoury | The Netherlands
Project Mannoury: our award winning smart roof experiment
Maankwartier Heerlen | Netherlands
Award winning tree project in Heerlen
Bloc Roof Manchester | UK
Smart Blue-Green Roof
Greenwich Wharf London | UK
Podium level attenuation and planter irrigation
TKI Project SmartRoof 2.0 | Netherlands
Blue-green Permavoid roof independently tested
Orlysquare Amsterdam | Netherlands
BlueGreen roof on top of a train station
Find your local distributor nearby.
Permavoid source control ensures that no precious water goes to waste by catching, storing and reusing stormwater for irrigation, evaporation and infiltration. Find your local Permavoid distributor here to learn more about the technology and become part of the international movement.
