Here at New Dawn, our services extend well beyond just installing permeable paving. We have assisted numerous architects, engineers and planners in successfully implementing permeable paving into projects large and small.
But why do you need to use permeable paving? Typically in new developments, it is in response to specific planning regulations and restrictions. Here’s just some examples of how permeable paving can be utilised to get the most out of your build.
Permeable space (or site coverage)
One of the major limitations in designing a development is permitted site coverage. Planning overlays impose a minimum percentage of permeable space that must be maintained. Impermeable (non-permeable) surfaces in this calculation include the building footprint, concrete driveways, swimming pools, and any other surface or structure that does not allow water to drain into the ground beneath. Permeable surfaces include landscaping such as garden beds and lawns, and permeable paving.
Given that in most metro developments space is at a premium (and even more so in planning a new subdivision!) anything that you can do to reduce your impermeable coverage will allow you to design a building with a bigger footprint. So changing a concrete driveway (impermeable) to a permeable paved driveway will decrease your site coverage without changing the functionality of the site.
The start of a permeable basement ramp on a small block in Armadale VIC in order to increase the permeable space of the development.
Stormwater management objectives
Melbourne Water and the Victorian planning regulations set a series of stormwater management regulations that new residential subdivisions must meet (Clause 56.07-4 of the Victorian Planning Provisions). Each council has a slightly different way of assessing compliance with these requirements, but it usually involves using a computer model to assess the compliance.
Basically, the planning regulations require stormwater run-off from impermeable areas (roofs, driveways etc.) to be “treated” to reduce the rate at which it enters the stormwater system and to reduce the amount of particulate matter and pollutants it carries. Typically this is achieved through a combination of water storage, retention systems and rain gardens or pavement buffer strips.
Permeable areas (such as permeable driveways) do not need “treatment” and by increasing permeable space on the site, can reduce the amount of other treatments that might be required.
Permeable driveway in Essendon VIC to achieve compliance with the development’s STORM assessment.
When assessing new building proposals, council will often insist on the retention of significant trees, as they provide a variety of environmental benefits, including in combating the Urban Heat Island effect. During construction, they must be protected as per Australian Standard AS4970-2009 (Protection of Trees on Development Sites). If you want to build within the Tree Protection Zone (TPZ) then typically a maximum incursion of just 10% is permitted. This includes impermeable hard surface coverings such as normal driveways. However, use of permeable surfaces that allow water infiltration into the rootzone is permitted. Therefore, if you want to build a driveway through a tree protection zone then it needs to be constructed in permeable paving.
Furthermore, when installing a permeable driveway within a TPZ, extreme care needs to be taken during excavations. AS4970-2009 has several restrictions on excavations in a TPZ so it is essential that the permeable paving contractor is experienced in how to successfully prepare the subgrade whilst complying with the restrictions on excavations. A supervising arborist is sometimes also required onsite, especially if the pavement is to be installed in the Structural Root Zone.
Permeable footpaths and driveway through a tree protection zone in Reservoir VIC.
What’s the best way to meet these requirements?
Honestly, the best way to achieve a perfect result with permeable paving is to ensure you use a specialist for your project!
Here at New Dawn, we pride ourselves on permeable paving perfection. We’re committed to ensuring your project achieves compliance and works for the end user. We are always available at the planning stages to answer questions or provide further information as required. During installation, we ensure the pavement installation complies with the various planning requirements, and on completion provide a certificate of compliance for the works and any further information required for sign-off.