The calculator designed to measure the Difference you can make using TRUEGRID Permeable Pavers.
The information below gives the basis for the Environmental claims made by the calculator for a sample area of 100m2 of Pro Plus but excludes the information provided on the Product page for material requirements.

CO2 Saved:

The table below has been taken from https://www.boral.com.au/sites/default/files/media/field_document/17677_ENVISIA_Technical_BroUpdate_LR_0.pdf as it is indicative of the amount of carbon produced by the concrete industry in Australia for every cubic meter of concrete supplied.

Allowing for a conservative outcome with the use of 20% fly ash in place of cement and based on other research the amount of CO2 in placed concrete has been defined as 290kg/m3.

To confirm the estimated cubic metres of Concrete to be placed we choose a slab depth for the square metres of TRUEGRID to be supplied as per the examples below based on 100 sq mts:

1. Standard yard hardstand for distribution centre Concrete 180mm deep–uses 0.18m3 concrete per m2 surface area, times by 290kg = 52.2 kg/m2 surface area–100m2 = 5,220kg CO2 avoided.

2. Normal Roadway Concrete 150mm deep – uses 0.15m3 concrete per m2 surface area, times by 290kg = 43.5kg/m2 surface area–100m2 = 4350 kg CO2 avoided

3. Standard pathway Concrete 100m deep–uses 0.1m3 concrete per m2 surface area, times by 290kg = 29kg/m2 surface area–100m2= 2900kg avoided.

For the example shown for the calculator example 3 is used for the analysis as it is the best-case scenario.

The comparison for trees planted the variance in sourcing adequate information on the immediate impact of CO2 Sequestered in saplings varies based on species type and density.

The table below produced by the EPA in the USA gives an overview of the amount of variance based on years of growth, type of tree, rate of growth and of course survival rate of the tree.

See: https://www3.epa.gov/climatechange/Downloads/method-calculating- carbon-sequestration-trees-urban-and-suburban-settings.pdf

One Tree Planted (https://onetreeplanted.org/blogs/stories/how-much-co2-does-tree-absorb)

Notes:

To determine the amount of carbon dioxide a tree can absorb, we combine average planting densities with a conservative estimate of carbon per hectare to estimate that the average tree absorbs an average of 10 kilograms, or 22 pounds, of carbon dioxide per year for the first 20 years.

This was determined by reviewing the planting density of our projects around the world, with an average planting density rate of 1,000/trees per hectare. With carbon estimates, we like to err on the side of being conservative to avoid over inflating the potential benefits, which is why we selected 10 tons per hectare per year. Dividing 10 tons per hectare by 1,000 trees per hectare gets us an average value of 10 kilograms/22 pounds per tree per year. This is a little less than half of the commonly cited 48 pounds per tree per year, which gives us confidence that we are in the same ballpark as the accepted, de facto number, but are now being more conservative, and have a way to back it up. Vague to make this number meaningful.

This average is due to the increase over time as the tree matures, for example under the EPA table a 20-year-old fast growing Hardwood tree would absorb nearly 19kg per year and a slow growing tree the same age only 5kg per year.

To remain conservative given the variables involved the Calculator works by taking the first 10 entries for a fast-growing Hardwood tree on the EPA table above and then dividing the number by 10 to give a starting average.

This equates to 9.5lbs (4.3kg) per tree which in the Calculator example above for 100m2 gives 2,897kg CO2 / 4.3kg = 673 established trees required for 1 year to offset the CO2 for the equivalent area in Concrete.

Plastic Out of Landfill:

Each individual piece of Pro Plus weighs 2.342kg and is made from 100% by weight of recycled HDPE. The calculator converts the weight to Kilograms per m2 by multiplying by 2.7503 which is the number of pieces of TRUEGRID per m2. For the example above 100m2 = 2.342 * 2.7503 * 100 = 644Kg of HDPE.

To allow the consumer an opportunity to make a comparison we use Milk Bottles to visualise the weight removed form landfill.

Visy’s HDPE and HDPE plastics are used extensively by the dairy industry for milk, and each bottle on average weighs 0.059 kg.

For the example above, Bottles = 644/0.05982= 10,764 (allowing for rounding)

HDPE Plastic bottles could be used to manufacture TRUEGRID, but the source product is contaminated by the range of PET and other materials used in the Milk Bottle industry.

Stormwater Detained:

For the product calculators the detention quantity is based on the type of surface and depth of subbase chosen. For the Environmental calculator the formula is as follows:

Detention Capacity = TRUEGRID area*Total Aggregate Depth * 40% Void space

For the 100m2 Example chosen= 100m2 * 247(200mm base+47mm fill in TRUEGRID) * 40%= 9.88m3 = 9,880 litres.

Please note that formulas are subject to rounding errors that may have a marginal effect on the final number shown.

Disclaimer

The online calculator is provided for illustrative purposes only, and the information obtained by using the online calculator is not and should not be taken as professional advice to any person or company. Whilst every effort has been made to ensure the integrity of the formulas in these calculators the accuracy of the results depends totally on the accuracy and comprehensiveness of the information entered by the user. The online calculator is not a substitute for obtaining professional advice and TRUEGRID accepts no liability whatsoever for any losses or liabilities allegedly arising from the use of the online calculator by any person or company.