50% of a new LEED home exterior is clad with salvaged brick; the remaining 50% is clad with wood. In order to earn a point under Materials and Resources Credit, Environmentally Preferable Products, which of the following must be true?

The LEED for Homes v4 rating system, under MR Credit 2: Environmentally Preferable Products, allows projects to earn points by using materials that meet specific environmental criteria. Siding is one of the eligible product categories. To earn the first tier of points (0.5 points) for this category, at least 50% of the product, calculated by cost or area, must be an Environmentally Preferable Product (EPP). The prompt states that 50% of the home's exterior is clad with salvaged brick. "Salvaged" or "reclaimed" materials are a primary type of EPP. Therefore, the project already meets the 50% threshold with the brick alone, qualifying it to earn a point.

A. All of the siding is FSC-certified: This is incorrect because 50% of the siding is brick, which is a masonry product and cannot be Forest Stewardship Council (FSC) certified.
B. Cladding combinations cannot earn points: This is incorrect. The LEED rating system is designed to accommodate mixed material assemblies and provides calculation methodologies for such combinations.
D. At least half of the wood siding is both reclaimed and local: This is not a requirement. While this would contribute to the EPP calculation, the project already qualifies for points based solely on the 50% salvaged brick. ---

1. U.S. Green Building Council. (2018). LEED v4 for Homes Design and Construction.

Page 109, "MR Credit 2: Environmentally Preferable Products, Step-by-Step Guidance, Step 2. Identify EPPs": This section lists the attributes that qualify a product as an EPP. The first attribute listed is "Reused or salvaged materials," which directly applies to the salvaged brick in the scenario.

Page 111, Table 11, "MR Credit 2: Environmentally Preferable Products": This table outlines the points available for different product categories. For "Siding," it explicitly states that a project earns 0.5 points if ≥50% of the siding is an EPP, and 1 point if ≥90% is an EPP. The scenario meets the 50% threshold.

2. Krygiel, E., & Nies, B. (2016). Green BIM: Successful Sustainable Design with Building Information Modeling. Sybex. (Note: While a commercial book, its detailed breakdown of LEED credits is often used in university courseware for architecture and sustainable design).

Chapter 7, "Materials and Resources": This chapter explains that the EPP credit in LEED for Homes is calculated based on meeting percentage thresholds for specific building components, such as siding. It confirms that salvaged materials are a key compliance path and that calculations are based on the total component assembly, allowing for combinations of materials.