The intent of the Materials Petal is to induce a successful materials economy that is non-toxic, transparent and socially equitable. Throughout their lifecycle, materials are responsible for many adverse environmental issues including illness, squandered embodied energy, pollution, and resource depletion. The Imperatives in this section aim to remove the worst known offending materials and practices. When impacts can be reduced but not eliminated, there is an obligation not only to offset the damaging consequences associated with the construction process, but also to strive for corrections in the industry. At the present time it is impossible to gauge the true environmental impact and toxicity of the built environment due to a lack of product-level information.

The Living Building Challenge envisions a future where all materials in the built environment are replenishable and have no negative impact on human and ecosystem health. The precautionary principle guides all materials decisions.

The Materials Petal has five Imperatives:
11: Red List
12: Embodied Carbon Footprint
13: Responsible Industry
14: Appropriate Sourcing
15: Conservation +Reuse

Additional clarifying information on these Imperatives can be found via the online Dialogue, as well as our Materials Petal Handbook.

11: Red List

The project cannot contain any of the following Red List materials or chemicals42.

  • Asbestos
  • Cadmium
  • Chlorinated Polyethylene and Chlorosulfonated Polyethlene43
  • Chlorofluorocarbons (CFCs)
  • Chloroprene (Neoprene)
  • Formaldehyde (added)
  • Halogenated Flame Retardants44
  • Hydrochlorofluorocarbons (HCFCs)
  • Lead (added)
  • Mercury
  • Petrochemical Fertilizers and Pesticides45
  • Phthalates
  • Polyvinyl Chloride (PVC)
  • Wood treatments containing Creosote, Arsenic or Pentachlorophenol

There are temporary exceptions for numerous Red List items due to current limitations in the materials economy. Refer to the Dialogue for complete and up-to-date listings.

Red List Footnotes

12: Embodied Carbon Footprint

The project must account for the total footprint of embodied carbon (tCO2e) from its construction through a one-time carbon offset tied to the project boundary.46

Embodied Carbon Footprint Footnotes


13: Responsible Industry

The project must advocate for the creation and adoption of third-party certified standards for sustainable resource extraction and fair labor practices. Applicable raw materials include stone and rock, metal, minerals,
and timber.47

For timber, all wood must be certified to Forest Stewardship Council (FSC)48 100% labeling standards, from salvaged sources, or from the intentional harvest of timber onsite for the purpose of clearing the area for construction or restoring/maintaining the continued ecological function of the onsite bionetwork.49

Responsible Industry Footnotes

14: Appropriate Sourcing

The project must incorporate place-based solutions and contribute to the expansion of a regional economy rooted in sustainable practices, products and services.50
Source locations for materials and services must adhere to the following restrictions51:


* Zone designation refers to the location of the manufacturing facility only; raw material sourcing is not

Appropriate Sourcing Footnotes

15: Conservation + Reuse

The project team must strive to reduce or eliminate the production of waste during design, construction,operation, and end of life in order to conserve natural resources.
The project team must create a Material Conservation Management Plan64 that explains how the project optimizes materials in each of the following phases:

  • Design Phase65, including the consideration of appropriate durability in product specification
  • Construction Phase, including product optimization and collection of wasted materials
  • Operation Phase, including a collection plan for consumables and durables
  • End of Life Phase, including a plan for adaptable reuse and deconstruction.

During construction, the project team must divert wasted material from66 to the following levels:

Hazardous materials in demolition waste, such as lead-based paint, asbestos, and polychlorinated biphenyls (PCBs), are exempt from percentage calculations. For all Typologies, there must be dedicated infrastructure for the collection of recyclables69 and compostable food scraps. For a Neighborhood project, there must be onsite compost facilities to accommodate all food scraps.

Conservation + Reuse Footnotes