Permeable Paving; not just a trend, a necessity

Wherever you look, urban development in Melbourne is booming. Strict planning restrictions apply to new single dwelling builds as well as townhouses and subdivisions, in an effort to ensure the demands of Melbourne of the future are met today.

A key limiter in many developments, especially on small blocks in inner suburbs is site coverage – restrictions placed on how much of the site can be covered with an impermeable surface (such as a house or concrete driveway). This is one of the key factors in determining maximum floor space.

But what’s the drive for limiting impermeable surfaces? Put simply, it’s all about stormwater management. Impermeable surfaces drain water into the stormwater system, whilst permeable surfaces allow water to drain back into the ground. This is a key concept of Water Sensitive Urban Design (WSUD), which all Australian councils have implemented policies governing.

What does this have to do with paving? Permeable paving is paving where water drains through and soaks back into the ground, just as it does when it rains on the lawn at home. Because of this function, it counts as a permeable surface when calculating your site coverage. It’s also a critical tool in meeting WSUD criteria.

An additional benefit of fully permeable concrete is that it allows paving subgrades to be engineered to support heavy commercial applications. While the permeable concrete cannot be finished like normal concrete, a layer such as a resin bonded aggregate or engineered pavers should be applied as a hard wearing and aesthetically pleasing top course.

Why not use use permeable concrete?  There are many limitations to its use that make it unsuitable for use in WSUD applications.  These include; compromising aesthetics, strength and durability compared to normal paving or concrete applications. The combination of reinforced permeable concrete with an extensive range of paving finishes makes circumventing these challenges possible.

With Melbourne’s relentless urban development and increasingly strict planning requirements, the use of permeable paving will continue to grow and become more important in meeting site coverage requirements and WSUD criteria.