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Permcalc – Free permeable pavement designs from Brett Landscaping


Landscapers, architects and developers can now create accurate, fully costed design suggestions for permeable paving solutions quickly and easily thanks to PermCalc, an innovative free-to-use online tool designed in-house by Brett Landscaping.

Accessed via the Brett website (www.brettpaving.co.uk/permcalc), PermCalc is ideal for any project which requires Sustainable Drainage System (SuDS) and creates authoritative data to enable decision makers to make informed choices about the benefits of permeable paving.

“A lot of people are unsure about the cost implications of permeable pavements, so PermCalc has been developed to demystify the process by providing a true, like-for-like, comparison with non-permeable solutions” explains Andrew Gill, Marketing Manager at Brett Landscaping.

PermCalc users are taken through a step-by-step process which is based on the current British Standard guidance for designing permeable pavements. This requires them to enter structural and hydraulic data about the proposed site as well as average rainfall, the type of vehicle load the paving must withstand and any known pollutants that will impact upon water quality.

PermCalc can also be used to create different proposals based upon the likelihood of severe weather in order to produce a design that will withstand and safely manage the passage of water in a ‘worst case scenario.’ The design methodology of PermCalc also enables users to input an excess based on anticipated future changes, reflecting the importance to planners of climate change in long-term drainage management.
Crucially, PermCalc undertakes a range of tasks automatically for the most comprehensive design suggestion of a project. Unlike alternative permeable pavement design methodologies, Brett Landscaping believes it is essential to advise on potentially ‘hidden’ aspects that can affect the performance of a permeable paving solution since no site is a truly isotropic plane.

“Slopes, adjacent roofs, additional non-permeable areas around the perimeter of a site – all of these factors can alter the flow of water, it is therefore crucial that architects and developers provide a full picture of the site layout,” confirms Andrew Gill. “Users are prompted at each stage to enter all relevant site information, this is then factored in to the PermCalc calculation process to create the optimal design suggestion.”
At the end of the design process, PermCalc provides the user with fully costed design suggestions for the project. This enables planners to gain an accurate comparison with non-permeable solutions. Most importantly, designs can then be edited so that users can tweak volumes and prices to suit their specific requirements and create various differing scenarios.

“We are aware that permeable paving is still a relatively new proposition for some designers and planners, therefore an integral element of the PermCalc philosophy is that it will help designers with developing quick ‘what if’ scenarios,” underlines Andrew Gill.

“We invite users to try the software for themselves to test the many options available and so determine the optimum permeable pavement solution for their own projects.”

Permeable paving from Brett Landscaping has been specifically designed to provide manageable, environmentally-friendly surface water management systems that are fully SuDS-compliant. Permeable paving meets the requirements of landscapers in terms of the fast dispersal of water from surfaces, as well as the removal of pollutants before the water is drained into the soil.

By removing the need for filtration traps, permeable paving from Brett Landscaping requires minimum maintenance. Recent tests – as demonstrated on the Brett Landscaping YouTube channel – confirm that the company’s permeable paving solutions continue to perform even on a lightly maintained, eight-year-old site. The video clearly shows how, when 400 gallons of water was poured onto a small area of permeable pavement no ponding or run-off occurred and the surface of the site was dry within an eight minute period.
At the same time, Brett’s commitment to eye-catching design and high-quality installation support means that specifiers and landscapers can make permeable paving an integral part of aesthetically pleasing paved environments.

In order to fully support PermCalc within the market Brett Landscaping can now also offer three levels of free training to design consultants and local authority personnel, as follows:-
1) How to use Brett PermCalc – I hour Training session
2) Permeable pavement design and construction – 2 hour training session
3) Permeable pavement design, construction, adoption and maintenance – 3 hour training session

This training is especially relevant to highway engineers and those already working within, or establishing, the new SuDS Approval Bodies (SABs) envisaged under the 2010 Flood and Water Management legislation – contact Brett Landscaping on projectdesigner@brett.co.uk to find out more.