LEED Point Rating System
Materials Credit 4
The requirements of this credit state: "use materials with recycled content such that post-consumer recycled content constitutes at least 5% of the total value of the materials in the project OR combined post-consumer and one-half of the post-industrial recycled content constitutes at least 10%."
This percentage is determined by multiplying the cost of an item by the percent of recycled materials (on a mass basis) that make up that item. Supplementary cementitious materials, such as fly ash, silica fume, and slag cement are considered post-industrial. Furthermore, using recycled concrete or slag as aggregate instead of extracted aggregates would qualify as post-consumer.
Although most reinforcing bars are manufactured from recycled steel, in LEED, reinforcing is not considered part of concrete. Reinforcing material should be considered as a separate item.
This credit is worth 1 point for the quantities quoted above and 2 points for an additional 5% post-consumer recycled content, OR an additional 10% combined post-consumer and one-half post-industrial recycled content.
Examples of LEED credits that can be earned by utilizing concrete in the construction of parking areas:
(Sustainable Sites Credit 6.1)
(Materials Credit 2)
(Materials Credit 4)
(Materials Credit 5)
(Sustainable Sites Credit 7.1)