4.1 Intended Use—The intended use of this guide is to provide general information to practitioners in the fields of vegetative (green) roof design and construction. The guide encourages innovative but responsible vegetative (green) roof design, with a focus on performance and quality assurance. Numerical ranges, practical minimums, and benchmarks that are incorporated in the guide are intended for reference. Design requirements for specific projects vary and therefore qualified professionals may prepare designs with features that may vary from the recommendations contained in the guide. In all instances, vegetative (green) roof system designs shall conform to the applicable code requirements of Federal, State, Provincial or local agencies with jurisdiction.

4.2 Users—Users of this guide include: planners, developers, architects, landscape architects, engineers, general contractors, subcontractors, owners, facility managers, financial organizations related to building industry, building materials and product manufacturers, government agencies including building officials, and other building professionals.

1.1 This guide identifies terminology, principles and fundamental concepts including those related to sustainability, technical requirements of construction, and types of vegetative (green) roof systems used on buildings.

1.2 The considerations for sustainable development relative to vegetative (green) roof systems are categorized as follows: environmental, social, and economic as consistent with Guide E2432. (See Appendix X1.)

1.3 This guide discusses technical requirements for vegetative (green) roof systems pertaining to the following categories: plants, media, wind scour resistance, soil reinforcement, separation or filter layers, drain layers, water retention layers, protection layers, and root penetration barriers.

1.4 This guide addresses intensive and extensive vegetative (green) roof systems for roofs up to 15 % slope. Roofing/waterproofing membranes and insulation are key components of vegetative (green) roof systems, but technical requirements regarding their role in such roof systems is beyond the scope of this guide.

1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.