GENERAL CHAPTER 1. SCOPE AND ADMINISTRATION 101 GENERAL SCOPE

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1 GENERAL The commentary is designed to provide guidance for the implantation of the National Green Building Standard (NGBS) (ICC ). Where appropriate, the commentary includes basic background information that helps in understanding the intent of a given practice and how the practice works. The commentary is not intended as a substitute for the provisions of the NGBS or as commentary that provides guidance on building design or engineering or building code requirements. The final interpretation of the provisions of the NGBS is in the purview of the Adopting Entity. CHAPTER 1. SCOPE AND ADMINISTRATION 101 GENERAL SCOPE The provisions of the NGBS apply to all types of residential construction inclusive of the building, site, lot, and accessory structures. Where only a part of the building is for residential use (mixed-use buildings), the NGBS applies only to the residential portion(s) of the building. (See Section 304 for additional guidance.) The NGBS applies to new residential construction projects and renovation of existing residential buildings, including historic buildings. The renovation provisions apply to all types of residential buildings including multi-unit buildings and residential portions of mixed-use buildings. The NGBS does not provide specific provisions for renovation of accessory structures. Therefore, renovation of an existing accessory structure has to result in a structure that complies with applicable provisions for new construction to achieve compliance with the NGBS. The building s occupancy is established in accordance with the governing local building code. Where the ICC family of building codes is adopted, chapter 3 of the International Building Code (IBC) is used to establish the occupancy category. All four types of residential occupancies addressed in the IBC are included in the scope of the NGBS: R1, R2, R3, and R4. Residential occupancies include buildings where the occupants are transient in nature (e.g., hotels) and buildings where the occupants are primarily permanent in nature (e.g., apartment buildings). The scope of the NGBS also includes one- and twofamily dwellings as defined in the International Residential Code (IRC). Buildings or portions thereof classified as institutional are not included in the residential occupancy and cannot seek compliance under the NGBS. Section 508 of the IBC provides additional requirements for mixed-use buildings, including provisions for height, allowable area, separation, incidental uses, etc. The NGBS and its criteria are also applicable to subdivisions and building sites intended for the eventual construction of buildings or additions thereto classified as residential occupancy. The terms subdivision, site, and lot are defined in chapter 2 of the NGBS. The terms subdivision and site are used interchangeably in the context of chapters 3 and 4 of the NGBS and apply to the compliance method for green subdivisions covered in Section 302. The term lot applies to the chapter 5 land development practices included in the compliance method of Section 303 for green buildings. The NGBS and its criteria further apply to alternations, additions, and renovations of existing single-family and multifamily residential buildings. Renovation is the more encompassing term and includes the process for restoring or improving an existing building or dwelling unit that may include changes to the landscape. The term alternation covers any construction and renovation to an existing structure that requires a permit. Alternations do not include additions. The term addition refers to an extension or ICC National Green Building Standard Commentary 1

2 increase in the floor area or height of a building or structure. The NGBS is applicable to all of these types of construction activities INTENT The NGBS establishes criteria for rating the reduction of environmental impact and the related performance improvements expected from implementing environmentally preferable design and construction practices. The criteria is expressed in terms of points assigned to individual green building practices and the minimum point thresholds required to achieve one of the four performance levels. (Refer to the chapter 3 commentary for additional information on the compliance method.) In addition, the NGBS assigns mandatory status to practices viewed as essential to the green building designation. All mandatory and optional practices are grouped into seven universally recognized green building categories, which are organized by chapters in the NGBS. These include: Chapter 4 Site Design and Development Chapter 5 Lot Design, Preparation, and Development Chapter 6 Resource Efficiency Chapter 7 Energy Efficiency Chapter 8 Water Efficiency Chapter 9 Indoor Environmental Quality Chapter 10 Operation, Maintenance, and Building Owner Education These green building categories are aligned with the primary guiding principles driving any green building project. Each category is associated with its own specific intent that serves the overall green building goals of reduced impact on nature s resources by providing: Land development practices that preserve and restore site features to the extent possible while reducing the effects of storm water runoff and enhancing the performance of buildings Design and construction practices that result in resourcing efficient building systems, minimizing material waste, and improving durability of materials and systems Building technologies and design techniques that aim at reducing the energy and water consumption needed to operate the building Materials and design features that improve the quality of the indoor environment Educational and operational resources that help owners and occupants achieve optimum longterm building performance Where appropriate, the NGBS and this commentary include focused intent statements to provide additional insight into the basis for the green building practices. Because new green building techniques and technologies are emerging at a rapid pace, the NGBS recognizes that flexibility is needed to permit innovative approaches and techniques not specifically enumerated by the provisions. Therefore, where warranted and consistent with the intent of the NGBS, the Adopting Entity (see Section 103) may award points to encourage the recognition of such technologies. The implementation of this guiding principle is further explained in Section Alternative Compliance Methods and Section Awarding Points. ICC National Green Building Standard Commentary 2

3 Practices selected from the NGBS must not violate the provisions of statutes and regulations governing construction of a given project in a given jurisdiction. The NGBS is intended to provide a method for improving a project s environmental performance beyond typical minimum practices or minimum code requirements. However, inclusion of materials or practices in the NGBS does not infer local code acceptability. It is therefore the responsibility of the building designer to ensure compliance with all applicable regulations REFERENCED DOCUMENTS Referenced documents are included in the provisions of the NGBS to provide additional criteria for compliance with prescribed measures and, in some cases, to provide alternative compliance criteria and methods (e.g., ENERGY STAR for homes as an alternative compliance for bronze-level energy requirements). All applicable requirements of the reference document must be met in order to demonstrate compliance with a mandatory provision of the NGBS or to receive points for a nonmandatory practice. Where a provision of the NGBS refers to a part of a specification, standard, or code, compliance with that specific part of the reference document is sufficient to meet that provision. Where a provision of the NGBS refers to a referenced document in its entirety, all of the relevant criteria of that document must be met to achieve compliance with that provision. The NGBS references the specific version/year of the document as listed in chapter 13. New editions of referenced documents do not supersede the referenced documents for the purpose of complying with the NGBS APPENDICES The 2012 NGBS includes five appendices: Appendix A Ducted Garage Exhaust Fan Sizing Criteria (referenced in Section 901.3(1)(c) of the NGBS); Appendix B Whole Building Ventilation System Specifications (referenced in Section of the NGBS); Appendix C Climate Zones Appendix D Examples of Third-Party Programs for Indoor Environmental Quality Appendix E Accessory Structures Appendices A and B are part of the NGBS and contain design information for mechanical systems. To qualify for points under Sections 901.3(1)(c) and of the NGBS, the design of the applicable mechanical systems must comply with the criteria of the corresponding appendices. Both appendices are extracted from ASHRAE Standard and are included with the NGBS to facilitate the design process. To facilitate the application of the practices that depend on the climate zone of the construction site location, appendix C provides climate zone designations by state, county, and territory. The climate zone designations are consistent with those published by the ICC. Appendix C is part of the NGBS. Appendix D provides a list of third-party certification programs that meet the intent of the NGBS for several practices in chapter 9 addressing source emission control. Appendix D is not part of the NGBS, and the listed programs are only examples of compliant programs. This list is not intended to be comprehensive. Because the updated NGBS includes substantial revisions to the third-party credentialing requirements, the consensus committee decided to provide this complimentary list to help users with interpretation and application of the new provisions. Other programs that are not listed in the appendix but comply with the requirements of the provisions can be used to achieve compliance with the applicable practices. ICC National Green Building Standard Commentary 3

4 Appendix E provides compliance criteria for accessory structures. It is not the intent of the NGBS to require compliance for accessory structures in order to achieve compliance for the primary building. The user should refer to Section of the NGBS. Appendix E is part of the NGBS only if specifically adopted by the Adopting Entity. Based on the compliance rules setup by the Adopting Entity, compliance with appendix E can be voluntary or mandatory. The intent for including provisions for accessory structures was to align the scope of the NGBS with the scope of minimum green building codes (e.g., International Green Construction Code, local green codes) where the NGBS is or can be referenced. Separating the provisions for accessory structures into a standalone appendix provides a wide degree of flexibility for the adopting entity with regard to establishing compliance rules based on the market preferences and requirements of locally adopted minimum building codes. 102 CONFORMANCE MANDATORY PRACTICES The NGBS is a rating system, which provides a menu of options for achieving a specified rating level expressed in terms of a minimum number of points. In addition to the minimum point thresholds, the NGBS designates select practices as mandatory. These practices are viewed as essential and universal for any project seeking a green rating (i.e., without these practices a home could be not considered green in the view of the consensus committee). Combining mandatory provisions with a point system provides the users with flexibility in selecting construction technologies appropriate for their projects, markets, and customers. All applicable mandatory practices must be implemented to qualify for any performance level of the NGBS. Certain practices in the NGBS are mandatory only at higher rating levels (e.g., Section 801.5). (Refer to the commentary in chapter 3 for additional information on the compliance method and mandatory practices.) CONFORMANCE LANGUAGE The NGBS is written in language conducive to implementation in design and construction and, as appropriate, verification of compliance. Chapters 1, 2, and 3 provide framework for the entire NGBS and are mandatory as reflected by use of the term shall. To comply with the NGBS, a project must satisfy all applicable provisions of chapters 1, 2, and 3. The practices in chapters 4-11 are mandatory only if the user claims the associated points toward a rating level or the practice is designated as mandatory. The practices in chapter 12 are mandatory as applicable to the scope of the specific remodeling activity as defined in that section. In those chapters, the practices use various forms of to be DOCUMENTATION In accordance with Section 103, administration of the NGBS is within the purview of the Adopting Entity. The Adopting Entity establishes an applicable verification protocol, including requirements for the documentation of compliance with the provisions and practices of the NGBS. The intent of this section is to provide flexibility for the Adopting Entity and the individual responsible for documentation in determining the type and method of compliance verification; the required documentation does not need to be excessive and should not create an unnecessary burden on the user or the Adoption Entity. Section of the NGBS provides a list of documents that the Adopting Entity may use for verification of compliance. In many cases, documentation that substantially verifies compliance with applicable green building practices may be provided by reference to common construction documents (e.g., plans and ICC National Green Building Standard Commentary 4

5 specifications listing products, written certifications by the builder indicating compliance with the specified practice). Additional methods acceptable for adequately demonstrating compliance include product specifications, manufacturers information, proof of purchase, and a wide variety of other documents. Where third-party certifications or accreditations are required by a practice to qualify for points, applicable certificates verifying conformance should be provided (e.g., Section 901.6(2)). Some practices in the NGBS specify the documentation required to qualify for points (e.g., Section requires documentation of the energy cost performance analysis) ALTERNATIVE COMPLIANCE The NGBS allows the Adopting Entity to recognize practices not explicitly listed in the NGBS. Section 301.2(3) establishes rules for assigning points to innovative products and practices. An alternative practice should meet the intent of another practice already listed in the NGBS or a broader intent of one of the chapters. It is not the intent of this provision to allow adoption of practices that provide a benefit not currently recognized by the NGBS. For example, sound control is not currently recognized by the NGBS as a green feature and does not fall under the alternative compliance clause. The Adopting Entity should establish a formal process for evaluating the suitability, applicability, and compliance of a proposed alternative practice with respect to the intent of the NGBS and the assignment of appropriate points. 103 ADMINISTRATION This section requires the Adopting Entity involved in administration of the NGBS to establish a verification process to validate claims of compliance to the specified rating levels. According to the definition in chapter 2, Adopting Entity is the government jurisdiction, green building program, or any other third-party compliance assurance body that adopts this standard, and is responsible for implementation and administration of the practices herein. The NGBS does not provide specific criteria for establishing a verification process. However, the framework for verification processes that are part of product certification services and building inspection procedures is well established in the construction industry. These processes follow accepted industry standards and typically include all or several of the following elements: 1. Criteria for maintaining independent third-party status 2. Review of design 3. Review of construction documentation 4. Review of performance data provided by other third parties in support of compliance claims 5. Inspections 6. Documentation of the review and inspection results 7. Educational requirements for inspectors/verifiers 8. Internal third-party procedures to ensure data quality and integrity 9. Procedure for awarding certification of compliance 10. Ongoing monitoring and continual improvement (e.g., continuing education of inspectors, audits of inspectors, internal reviews) 11. Oversight (e.g., by an accreditation agency) ICC National Green Building Standard Commentary 5

6 The Adopting Entity may perform all third-party functions with in-house staff, or it can have an arrangement with other independent organizations and/or individuals to provide some of the services. The NGBS certification program administered by the Home Innovation Research Labs is an example of a national program designed to meet the provisions of Section 103. Home Innovation serves as an Adopting Entity for the NGBS and establishes specific rules and procedures for demonstrating compliance. More information on the Home Innovation s verification program can be found at ICC National Green Building Standard Commentary 6