USGBC Updated LEED-AP-Homes Exam Questions and Answers by elif

TheLEED for Homes Rating System (v4)includes theEnergy and Atmosphere (EA) Prerequisite: Minimum Energy Performance, which requires compliance with theThermal Enclosure System Checklistto ensure proper insulation and airtightness for energy efficiency.

According to theLEED Reference Guide for Homes Design and Construction (v4):

EA Prerequisite: Minimum Energy Performance

The project must comply with the Thermal Enclosure System Checklist, which requires that all exterior walls be fully insulated to meet or exceed specified R-values before other components (e.g., shower stalls) are installed. Insulation must be installed behind shower stalls or other fixtures adjacent to exterior walls to prevent thermal bridging and ensure compliance. Non-compliance with the checklist prevents certification until corrected.

Source: LEED Reference Guide for Homes Design and Construction, v4, Energy and Atmosphere Prerequisite: Minimum Energy Performance, p. 112.

TheLEED v4.1 Residential BD+Crating system confirms:

EA Prerequisite: Energy Performance

All exterior walls must be insulated in accordance with the Thermal Enclosure System Checklist. If components like shower stalls are installed before insulation, the home cannot be certified until the walls are properly insulated to meet the checklist requirements.

Source: LEED v4.1 Residential BD+C, Credit Library, accessed via USGBC LEED Online.

The correct answer isthe home cannot be LEED certified until the walls are insulated in compliance with the Thermal Enclosure Checklist(Option D), as installing a shower stall before insulation violates the prerequisite’s requirement for proper insulation installation.

Why not the other options?

TheLEED for Homes Rating System (v4)awards points for theMaterials and Resources (MR) Credit: Environmentally Preferable Productsbased on the use of materials with sustainable attributes, such as concrete with fly ash (a recycled material that reduces the environmental impact of cement production). The scenario indicates that reducing fly ash content in some suspended slab areas due to weather-related curing concerns would cause the project to fall short of the credit’s threshold (e.g., 25%, 50%, or 90% by cost).

According to theLEED Reference Guide for Homes Design and Construction (v4):

MR Credit: Environmentally Preferable Products (1–4 points)

Use products that meet one or more of the following criteria for at least 25%, 50%, or 90% (by cost) of the total materials in the project:

Recycled content: Materials with pre- or post-consumer recycled content, such as fly ash in concrete.The percentage is calculated based on the total cost of qualifying materials across the project.Source: LEED Reference Guide for Homes Design and Construction, v4, Materials and Resources Credit: Environmentally Preferable Products, p. 160.

TheLEED v4.1 Residential BD+Crating system confirms this:

MR Credit: Environmentally Preferable Products

Concrete with fly ash qualifies as an environmentally preferable product if it contributes to the required percentage of material cost. Project teams must ensure compliance across all relevant components.

Source: LEED v4.1 Residential BD+C, Credit Library, accessed via USGBC LEED Online.

The most effective strategy is toignore the engineer’s recommendation and proceed with the original design(Option B). This ensures the project maintains the intended fly ash content to meet the credit threshold. Fly ash typically slows concrete curing, but modern mix designs and admixtures (e.g., accelerators) can mitigate weather-related delays without reducing fly ash content. The LEED AP should collaborate with the structural engineer to explore alternative solutions, such as adjusting the mix or using curing blankets, to maintain both structural integrity and credit compliance.

Why not the other options?

TheLEED for Homes Rating System (v4)addresses indoor humidity in warm, humid climates through credits likeIndoor Environmental Quality (EQ) Credit: Enhanced VentilationandEQ Prerequisite: Ventilation, which consider factors affecting moisture levels to maintain indoor air quality.

According to theLEED Reference Guide for Homes Design and Construction (v4):

EQ Credit: Enhanced Ventilation (1–3 points)

In warm, humid climates (e.g., climate zones 1–3), assess indoor humidity by considering infiltration (uncontrolled air leakage through the building envelope) and ventilation (controlled outdoor air introduction). These factors influence moisture ingress and must be managed to prevent high humidity levels.

Source: LEED Reference Guide for Homes Design and Construction, v4, Indoor Environmental Quality Credit: Enhanced Ventilation, p. 146.

TheLEED v4.1 Residential BD+Crating system confirms:

EQ Credit: Enhanced Ventilation

Infiltration and ventilation are critical factors in assessing indoor humidity in humid climates, as infiltration introduces moist outdoor air, and ventilation systems must be designed to manage humidity effectively.

Source: LEED v4.1 Residential BD+C, Credit Library, accessed via USGBC LEED Online.

The correct answer isinfiltration and ventilation(Option B), as these are the primary factors affecting indoor humidity levels in a warm, humid climate, requiring careful design to control moisture.

Why not the other options?

TheLEED for Homes Rating System (v4)includes theLocation and Transportation (LT) Credit: Community Resources and Services, which awards points based on the number of publicly accessible community services within 1/4 mile (0.4 km) for single-family homes or 1/2 mile (0.8 km) for multi-family projects. The question specifies a 1/2-mile radius, suggesting a multi-family context.

According to theLEED Reference Guide for Homes Design and Construction (v4):

LT Credit: Community Resources and Services (1–2 points)

Earn 1 point for at least 4 community services or 2 points for 8 or more services within 1/2 mile (0.8 km) walking distance for multi-family projects. Qualifying services include restaurants, schools, pharmacies, grocery stores, and places of worship (e.g., churches), provided they are publicly accessible.

Source: LEED Reference Guide for Homes Design and Construction, v4, Location and Transportation Credit: Community Resources and Services, p. 56.

TheLEED v4.1 Residential BD+Crating system confirms:

LT Credit: Community Resources and Services

Community services such as restaurants, schools, pharmacies, grocery stores, and churches within 1/2 mile (0.8 km) of a multi-family project count toward the credit if publicly accessible.

Source: LEED v4.1 Residential BD+C, Credit Library, accessed via USGBC LEED Online.

Evaluation of resources:

Three restaurants: All qualify as community services.

One school: Qualifies as a community service.

Two pharmacies: Both qualify as community services.

One church: Qualifies as a place of worship.

One grocery store: Qualifies as a community service.

Total: 3 + 1 + 2 + 1 + 1 =7 resources.

The correct answer isseven resources(Option C), as all listed services are publicly accessible and within 1/2 mile, contributing to the credit.

Why not the other options?

A. Five resources: This undercounts the qualifying services (7 total).

B. Six resources: This also undercounts the total (7).