Waste factors

[Elizabeth Grove]

Do you know where the IMPACT waste factors come from? Do the BRE use the WRAP database for example?

[Rich Haynes]

Hi Elizabeth,

We’ll have to check with BRE. The datasets are pretty much a black box, very little in the way of documentation.

Rich

[Calum8410]

Does the waste factor add to the quantity input into the tool? For example. If I input 10m3 of concrete with a waste factor of 10%, is the carbon measured on 11m3 or 10m3?

[Laura6380]

I second this question; I’m trying to work out if we should be putting the total volume of concrete expected to be supplied to the project (i.e. 11m3 in this example) as the project quantity, or if it should be the amount used in the final building (i.e. 10m3).

Essentially, does the 10% waste factor increase the amount of concrete above what we include as the input quantity, or does it take a portion out of what we specify as waste?

[Laura Campos]

Hi Calum & Laura,

The construction waste factors are automatically calculated by the software. This is assuming that your source data is giving you the finished building quantities.

From the example you mentioned, 10 m3 would be your input and the actual material used, plus 1 m3 for waste.

I hope this answer you question.