LEED (Leadership in Energy and Environmental Design Certification) Materials and Resources 4 — Questions and Answers
Question 1: A LEED project team is tracking construction waste. They generated 100 tons of waste and diverted 65 tons through recycling. What is their diversion rate?
- 35%
- 55%
- 65% (Correct answer)
- 75%
Correct answer: 65%
Diversion rate = (diverted waste ÷ total waste) × 100 = (65 ÷ 100) × 100 = 65%.
Question 2: Which of the following is considered 'pre-consumer' (also called 'post-industrial') recycled content?
- Crushed glass from recycled wine bottles
- Steel made from scrap collected at automobile junkyards
- Fly ash from coal combustion used in concrete (Correct answer)
- Reclaimed brick salvaged from a demolished building
Correct answer: Fly ash from coal combustion used in concrete
Pre-consumer (post-industrial) recycled content includes manufacturing byproducts diverted from waste streams before they reach consumers — fly ash from power plants is a classic example.
Question 3: In LEED v4, the 'Interiors Life Cycle Impact Reduction' credit for interior projects rewards teams that reuse existing building elements. Which element would qualify as a reused interior component?
- A newly manufactured countertop made from recycled glass
- An existing raised access floor system retained from a previous tenant (Correct answer)
- A carpet tile with 50% post-consumer recycled content
- A bio-based acoustic ceiling tile with low VOC content
Correct answer: An existing raised access floor system retained from a previous tenant
Reusing existing interior elements — such as raised floor systems, interior walls, doors, or ceiling systems — avoids the manufacturing impacts of new materials and counts toward life cycle impact reduction.
Question 4: What LEED credit category specifically addresses the potential for materials to release harmful chemicals during a building's operational phase?
- Materials and Resources — Sourcing of Raw Materials
- Indoor Environmental Quality — Low-Emitting Materials (Correct answer)
- Sustainable Sites — Site Assessment
- Energy and Atmosphere — Fundamental Commissioning
Correct answer: Indoor Environmental Quality — Low-Emitting Materials
Low-Emitting Materials is an Indoor Environmental Quality credit that limits VOC emissions from installed products to protect occupant health after the building is occupied.
Question 5: Under LEED v4's Construction and Demolition Waste Management credit, which of the following must a project team document?
- The names of all subcontractors involved in waste handling
- The total weight or volume of waste generated and the diversion rate achieved (Correct answer)
- The cost savings from selling recyclable materials
- The carbon emissions avoided by diverting waste from landfill
Correct answer: The total weight or volume of waste generated and the diversion rate achieved
LEED requires documentation of the total waste generated and the percentage diverted from landfill through recycling, reuse, or composting to verify credit compliance.
Question 6: Which strategy would contribute most directly to achieving LEED's 'Building Life-Cycle Impact Reduction' credit?
- Installing high-efficiency HVAC equipment to reduce operational energy
- Reusing an existing historic building structure rather than demolishing and rebuilding (Correct answer)
- Selecting paints with zero VOC content for interior walls
- Using locally sourced stone for exterior cladding
Correct answer: Reusing an existing historic building structure rather than demolishing and rebuilding
Reusing an existing building's structure and envelope is the most impactful strategy for this credit because it avoids the embodied carbon and resource use associated with new construction materials.
Question 7: Under LEED v4, what is the minimum number of permanently installed building products needed to earn points under the Building Product Disclosure and Optimization credits?
- 5 products from 3 different manufacturers
- 10 different permanently installed building products (Correct answer)
- 20 products representing 90% of total material cost
- At least 50% of total materials by cost must be compliant
Correct answer: 10 different permanently installed building products
LEED v4 requires at least 20 different permanently installed products meeting the credit criteria to earn one point under most Building Product Disclosure and Optimization credits.
LEED (Leadership in Energy and Environmental Design Certification) Materials and Resources 4
A LEED project team is tracking construction waste.
They generated 100 tons of waste and diverted 65 tons through recycling.
What is their diversion rate?