Cost savings through the re-use of secondary aggregates.

The reuse of local or secondary aggregates can provide a cost saving during the construction of the roofs within a development.

The cost of growing mediums is in the region of £10-£15/m². Although there will be a cost incurred if materials such as brick and concrete are used from site in terms of crushing to the required grade, screening and transportation within site this will be minimal.

A 1000m² green roof could potentially save the developer £10,000 off the cost of the materials needed on the roof. Inverted roofs require hard landscape features such as paving slabs to prevent the possible flotation of the insulation. The cost of paving is in the region of £15/m².

The required weight to prevent flotation can be achieved by the use of secondary aggregates in a green roof system thus leading to a cost saving by eliminating the use of paving slabs.

The re-use of local aggregates can mean that green roofs are competitively priced with conventional inverted methods.