USGBC LEED-AP-BD+C - LEED AP Building Design + Construction (LEED AP BD+C)

For LEED BD+C Materials and Resources (MR) Credit: Building Product Disclosure and Optimization – Sourcing of Raw Materials, Option 2, a product contributes based on its cost and sustainability attributes.

Given the bamboo entrance doors are Rainforest Alliance certified, and the glass inserts contain 100% pre-consumer recycled content, these materials qualify under the Leadership Extraction Practices.

The total material cost per door is $200.

The glass inserts ($150) are 100% pre-consumer recycled and count fully.

The bamboo ($50) also qualifies due to its sustainability certification.

Since only the glass contributes to the calculation, the total value contributing to the credit is $100 per door, or $100.00 total for both doors.

(Source: Official LEED BD+C Reference Manual)

Detailed Explanation:

The design charrette is a collaborative, multidisciplinary session aimed at optimizing green strategies throughout the project. This early-phase effort allows stakeholders to explore synergies among building systems, identify sustainability opportunities, and align project goals with LEED requirements. It is a prerequisite for the Integrative Process, fostering holistic design and operational performance improvements.

According to the LEED v4: Building Design + Construction Guide, the location of CO2 sensors in naturally ventilated spaces to comply with the Indoor Environmental Quality Prerequisite, Minimum Indoor Air Quality Performance is between 3 ft. and 6 ft. (1 m and 2 m) above the floor. This is one of the requirements for Option 2. Naturally Ventilated Spaces, which applies to projects that rely on natural ventilation for all or part of the occupied spaces. The CO2 sensors must be located in each zone with natural ventilation openings, and must be capable of generating an alarm when the CO2 concentration exceeds the design value1.

The other choices are not correct, because:

At least 6 ft. (2 m) above the floor is the location of CO2 sensors in mechanically ventilated spaces, not naturally ventilated spaces1.

At least 3 ft. (1 m) away from windows is a general guideline for locating CO2 sensors, but it does not specify the height above the floor2.

On the ceiling 3 ft. (1 m) away from adjacent walls is not a recommended location for CO2 sensors, as it may not reflect the actual CO2 concentration at the breathing zone of the occupants2.

The Solar Reflectance Index (SRI) is a measure of the roof’s ability to reject solar heat, as shown by a small temperature rise. It is defined so that a standard black (reflectance 0.05, emittance 0.90) is 0 and a standard white (reflectance 0.80, emittance 0.90) is 100. SRI is calculated using the roof surface’s Solar Reflectance (SR) and Thermal Emittance (TE). SR is the fraction of solar energy that is reflected by the roof, and TE is the relative ability of the roof surface to radiate heat. Therefore, SRI includes the measure of a material’s ability to reflect solar radiation, but not its ability to absorb or emit thermal radiation.

The intent of the Sustainable Sites Prerequisite. Construction Activity Pollution Prevention is to reduce pollution from construction activities by controlling soil erosion, waterway sedimentation and airborne dust generation. The LEED v4 Reference Guide for Building Design and Construction states that "construction activities can have significant negative impacts on the environment, both at the project site and beyond. Erosion and sedimentation can degrade water quality, damage aquatic habitats, and increase flooding risks. Airborne dust can affect air quality, human health, and visibility. Construction vehicles and equipment can generate noise, traffic, and greenhouse gas emissions"1. The project team must implement an erosion and sedimentation control (ESC) plan that conforms to the 2012 U.S. Environmental Protection Agency Construction General Permit or local equivalent, whichever is more stringent. The ESC plan must cover all construction activity on the project site, including clearing, grading, excavating, and demolition.

Interior paint must always be included in Materials and Resources credits. This is because interior paint is considered as a permanently installed product, which is defined by the LEED v4 Reference Guide for Building Design and Construction as "a product that is installed in a project permanently or semi-permanently, such that removal would require demolition or substantial renovation."1 Permanently installed products must be included in the calculations for the following Materials and Resources credits: Building Life-Cycle Impact Reduction, Building Product Disclosure and Optimization - Environmental Product Declarations, Building Product Disclosure and Optimization - Sourcing of Raw Materials, and Building Product Disclosure and Optimization - Material Ingredients.1 The other options are not always included in Materials and Resources credits. Faucets (option A) and fire suppression systems (option D) are considered as mechanical, electrical, and plumbing components, which are excluded from the scope of Materials and Resources credits unless they are specifically addressed by the credit requirements.1 Furniture (option B) is considered as a non-permanently installed product, which is optional to include in Materials and Resources credits, except for the Building Product Disclosure and Optimization - Material Ingredients credit, where furniture must be included if it is within the project scope.1 References: LEED v4 Reference Guide for Building Design and Construction, p. 5791; LEED v4 Reference Guide for Building Design and Construction, p. 5801; LEED v4 Reference Guide for Building Design and Construction, p. 5811; LEED v4 Reference Guide for Building Design and Construction, p. 5821; LEED v4 Reference Guide for Building Design and Construction, p. 5831

The Energy and Atmosphere Credit, Renewable Energy Production rewards projects that use renewable energy systems to offset building energy costs1. According to the LEED Reference Guide for Building Design and Construction2, the credit has two options: Option 1. On-Site Renewable Energy and Option 2. Off-Site Renewable Energy. Option 1 requires the project to use renewable energy systems that are located on the project site and that produce electricity or thermal energy for the project. The amount of renewable energy production is calculated based on the percentage of the annual energy cost that is offset by the renewable energy systems. Option 2 requires the project to use renewable energy systems that are located off the project site and that are owned by the project or have a long-term contract with the project. The amount of renewable energy production is calculated based on the percentage of the annual energy use that is offset by the renewable energy systems.

Therefore, among the given options, only Option D is relevant to the credit requirements, as it implies that the solar photovoltaic system is located on the project site and that the produced electricity is consumed by the project. The other options, such as carbon offsets, daylighting strategies, and passive solar strategies, are not directly related to the credit requirements, although they may have other benefits for the project.

Detailed Explanation:

To earn 5 points under the Materials and Resources (MR) Credit for Building Life-Cycle Impact Reduction, at least 50% of the surface area of the existing building structure and envelope must be reused. This strategy preserves the embodied energy in the building materials, reducing the environmental impact of new material extraction, processing, and transportation, which is a core focus of LEED's sustainable building strategies.

SRI generally decreases with age

The Solar Reflectance Index (SRI) is a measure of the ability of a surface to reflect solar heat, as shown by a small temperature rise. It is calculated using the values of solar reflectance and thermal emittance of the surface. The higher the SRI, the lower the heat island effect. However, SRI generally decreases with age due to factors such as weathering, dirt accumulation, and biological growth. Therefore, the Sustainable Sites Credit, Heat Island Reduction takes into account both new and three-year aged SRI values for roofing material to ensure that the material maintains a high level of reflectance over time.

According to the U.S. Green Building Council (USGBC) and U.S. Department of Energy, buildings account for approximately 40% of total energy consumption in the United States.

This includes electricity, heating, and cooling loads across residential, commercial, and industrial buildings.

Buildings are the largest energy consumers, surpassing transportation and industry sectors.

LEED emphasizes energy efficiency to help reduce this 40% energy demand.

Buildings account for 40% of all energy consumption, making Option C the correct answer.

(Source: Official LEED BD+C Reference Manual)