Pass the USGBC Leadership in Energy and Environmental Design (LEED) LEED-Green-Associate Questions and answers with CertsForce

One of the causes of surface water degradation is the expansion of impervious surfaces. Impervious surfaces are those that do not allow water to infiltrate into the soil, such as roads, parking lots, rooftops, and sidewalks. Impervious surfaces increase the amount and speed of stormwater runoff, which can carry pollutants, sediments, nutrients, and pathogens into surface water bodies such as streams, rivers, lakes, and oceans. Impervious surfaces also reduce groundwater recharge, lower base flow in streams, increase flooding and erosion, alter streammorphology and habitat, and affect water temperature and dissolved oxygen levels2. Therefore, impervious surfaces can have significant negative impacts on the quality and quantity of surface water resources. References: Surface Water as a cause of land degradation from dryland salinity3; What is Water Pollution?4

Per the LEED v4 BD+C Reference Guide, the baseline for energy performance evaluation is based on:

"ANSI/ASHRAE/IESNA Standard 90.1-2010" for most projects under EA Prerequisite: Minimum Energy Performance and EA Credit: Optimize Energy Performance.

This standard sets the minimum energy efficiency requirements for buildings (excluding low-rise residential) and is the benchmark against which a project's proposed design is compared when using the energy simulation modeling method (whole building energy simulation).

ASHRAE 90.1-2010 defines criteria for HVAC systems, building envelope, service water heating, power, lighting, and other systems affecting energy use.

LEED requires performance above this baseline to earn points.

The other options are not appropriate baselines:

A. SMACNA: Refers to HVAC ductwork and air quality guidelines, not energy baseline standards.

B. ENERGY STAR®: Is a benchmarking tool, not a baseline standard used in energy modeling.

D. ASHRAE 62: Covers ventilation and indoor air quality, not energy performance.

Therefore, the correct baseline standard is ASHRAE 90.1-2010.

Covering duct work with plastic is a strategy for improving indoor environmental quality during construction. Covering duct work with plastic prevents dust, debris, and contaminants from entering the ducts and affecting the air quality of the building. This also reduces the need for cleaning and maintenance of the ducts after construction. The LEED Green Associate Candidate Handbook states that one of the strategies for achieving indoor environmental quality is to “protect ducts during construction by sealing or covering with plastic” [1, p. 16]. References: LEED Green Associate Candidate Handbook, [Indoor Air Quality During Construction | U.S. Environmental Protection Agency]

According to LEED v4, the commissioning authority (CxA) should be contracted before the end of the Design Development (DD) phase and should be involved in the project team from early in the Schematic Design (SD) phase1.

References := LEED v4: Building Design + Construction Guide, LEED v4 -U.S. Green Building Council, SBGD - Part D – ConsultantScopes of Work 3. Commissioning Authority, What’s new in LEED V4 – Commissioning Changes - Steven Winter …, LEED ENHANCED COMMISSIONING | Steps and Downloads

Xeriscaping is a landscaping practice that uses drought-tolerant native and adaptive plants to reduce water use and maintenance. Xeriscaping also incorporates other strategies such as mulching, efficient irrigation, soil improvement, and appropriate design and zoning. By using xeriscaping, projects can conserve water, protect natural habitats, reduce stormwater runoffand pollution, and enhance the aesthetic and ecological value of the site. References: LEED v4 Reference Guide for Building Design and Construction, p. 123 1; [Xeriscape Colorado website]

Tightly sealed (air-tight) buildings are often highly energy-efficient, particularly important in hot, humid climates like the tropics, where air conditioning demand is high. However, these airtight designs can limit fresh air exchange and potentially reduce indoor air quality (IAQ) unless carefully managed.

This sets up a trade-off scenario:

EA Credit: Optimize Energy Performance encourages tightly controlled environments to reduce energy consumption (especially from HVAC systems).

IEQ Credit: Enhanced Indoor Air Quality Strategies promotes fresh air circulation, filtration, and contaminant control to maintain health and comfort.

From LEED v4 BD+C Reference:

"Achieving high energy efficiency through airtightness must be balanced with adequate ventilation and IAQ strategies to ensure occupant health and comfort."

Therefore:

Option B is correct, representing this trade-off.

Option A (metering and construction IAQ) doesn’t reflect the trade-off in building operation.

Option C includes demand response, which is about energy grid participation, not IAQ.

Option D (heat island and thermal comfort) relates to exterior design and comfort, not air-tightness vs IAQ.

These strategies are core components ofLow Impact Development (LID)andgreen infrastructureapproaches for rainwater management:

“LID emphasizes… minimizing land disturbance, preserving vegetation, minimizing impervious cover…”

These help reduce runoff volume and replicate the site’s natural hydrology, improving rainwater management.

The project boundary is the area within which the project team has authority to implement the LEED requirements. It is important to clearly identify the project boundary to define the limits of site disturbance, which can affect the environmental performance of the project. For example, limiting site disturbance can help reduce soil erosion, protect natural habitats, and conserve water resources. The project boundary also determines the scope of the site assessment and the applicability of some credits. References: LEED v4 BD+C Reference Guide, Introduction, page 13

The use of native plant species, captured rainwater, and evapotranspiration controllers are all strategies that can contribute to reducing outdoor water use. Native plants are adapted to local conditions and typically require less water than non-native species. Captured rainwater can be used for irrigation, reducing the need for potable water. Evapotranspiration controllers adjust irrigation schedules based on weather conditions and plant needs, preventing overwatering. References: LEED Green Associate Candidate Handbook, U.S. Green Building Council resources

Integrated Project Planning and Design is a prerequisite for healthcare facilities under LEED v4. The intent is to maximize opportunities for the adoption of cost-effective integrated green design and construction strategies as early as pre-design1.

LEED v4 | HPAC Engineering1