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

Reducing the envelope load involves minimizing the heat that enters or escapes through a building’s envelope (walls, windows, roof, etc.). Summer solar shading is an effective strategy to block direct sunlight during warmer months, decreasing the cooling load on the HVAC system. This method helps reduce solar heat gain, which lowers energy usage for cooling. Other options like maximizing daylighting (B) increase natural light but may also increase heat gain, and decreasing the opaque wall area (C) can actually increase energy loss. Economizers (D) are HVAC strategies and don’t directly reduce the envelope load.

To qualify for the Sustainable Sites (SS) Credit: Site Development - Protect or Restore Habitat, Option 1, a project must use native or adapted vegetation and restore at least 30% of the previously disturbed site area, including the building footprint (C). This requirement supports biodiversity by using plants suited to the local climate and ecosystem. Restoration of disturbed land helps improve ecological health and reduces dependency on irrigation, fertilizers, and other resources.

To evaluate the Location and Transportation (LT) Credit: Reduced Parking Footprint, the project team should be aware of the minimum number of parking spaces required by the zoning code (D). This credit aims to reduce the environmental impact of parking by minimizing the number of spaces provided, encouraging alternative transportation methods. Knowledge of local parking minimums helps the team ensure compliance with LEED while avoiding excess parking, which can contribute to urban sprawl and the heat island effect. Design guidelines and building code standards are not directly relevant to this credit.

In determining the LEED project boundaries, the LEED AP may include non-contiguous parcels of land if the parcels directly support or are associated with normal building operations and are accessible to the project’s occupants. This is according to the Minimum Program Requirements (MPRs) for LEED v4.1, which state that non-contiguous parcels of land may be included within the LEED project boundary if they meet these criteria1. Facilities such as parking lots, bicycle storage, shower/changing facilities, and/or on-site renewable energy that are outside of the LEED project boundary may also be included in certain prerequisites and credits if they directly serve the LEED project and are not double-counted for other LEED projects1. The other options are not valid reasons to include non-contiguous parcels of land within the LEED project boundary. Temporary uses such as parking or staging that are owned and managed by a third party do not directly support or are associated with normal building operations of the LEED project1. Existing public preservation easements or resource protection areas that are directly adjacent to the LEED project boundary are not considered as part of the LEED project boundary, unless they are owned by the project owner or the project team has permission to use them2. Land trusts or conservation organizations for which the LEED project provides financial support are not considered as part of the LEED project boundary, unless they are located within the same EPA Level III ecoregion as the project site3.

ASHRAE 62.1-2010 is the standard that an engineer should use when establishing minimum ventilation rates for a new mechanically ventilated space to earn Indoor Environmental Quality, Minimum Indoor Air Quality Performance. This is the standard referenced by the LEED v4 BD+C Reference Guide for this prerequisite. Local building code, International Mechanical Code 2012, and the ventilation code requiring the greatest volume of outside air are not acceptable alternatives for this prerequisite.

Increase the number of skylights

Skylights are openings in the roof or ceiling that allow natural light to enter the building. They can improve daylighting by providing more uniform and diffuse illumination, reducing the need for artificial lighting, and enhancing the visual comfort and well-being of occupants. Skylights can also reduce cooling loads by minimizing solar heat gain through the roof. However, skylights must be designed carefully to avoid glare, overheating, and heat loss issues.

According to the LEED v4: Building Design + Construction Guide, the owner or an owner’s representative must be a member of the integrated project team for the Integrative Process Prerequisite, Integrative Project Planning and Design. The owner or an owner’s representative is responsible for establishing the project’s vision, goals, budget, and schedule, as well as defining the owner’s project requirements (OPR) and participating in the design charrettes and reviews1. The owner or an owner’s representative also plays a key role in ensuring the continuity and alignment of the project’s performance and environmental objectives throughout all phases of the project1.

The other choices are not mandatory members of the integrated project team, although they may be involved in the integrative process depending on the project’s scope and needs. The general contractor is typically hired after the design phase and may not be involved in the predesign and schematic design analyses required by the prerequisite1. A LEED AP is a professional who has demonstrated knowledge and experience in applying the LEED rating system, but is not required to be part of the integrated project team, although it is recommended and rewarded by the LEED credit, Integrative Process1. The project’s mechanical engineer is one of the possible design consultants who may contribute to the integrative process, especially for the energy-related systems analysis, but is not required to be part of the integrated project team1.

LEED requires that at least 50% of a building’s annual electricity consumption be offset by green power or carbon offsets to achieve the Energy and Atmosphere Credit: Green Power and Carbon Offsets. For this building with a projected annual consumption of 2,200,435 kWh, half of this amount, 1,100,218 kWh, must be purchased from green sources to meet the credit requirements. This strategy helps mitigate carbon emissions by promoting the use of renewable energy.

Coordinating open space features early during the site planning phase is a viable strategy for optimizing open space under Sustainable Sites Credit, Open Space. This can help to preserve natural habitats, reduce heat island effects, and enhance human health and well-being. The credit requires that the project provide outdoor space that is at least 30% of the total site area, and that at least 25% of that outdoor space meets certain criteria for vegetated, pervious, or shaded areas. References:

LEED credit library: This is the USGBC’s comprehensive listing of all the LEED credits available in pursuing certification for your project. The credit library contains the requirements and guidance for each credit, as well as the web-based reference guide for the Building Design and Construction rating system.

Open Space: This is the specific credit page for the Open Space credit under the Sustainable Sites category. It provides the intent, requirements, and strategies for achieving the credit, as well as the number of points available and the applicable project types.

Step by Step Approach to Comply with the Open Space Credit in LEED v4: This is a blog post that explains the steps and calculations involved in complying with the Open Space credit. It also provides some examples and tips for optimizing open space design.

The Integrative Process credit, Integrative Process, requires the project team to conduct a preliminary analysis of the energy and water related systems during the pre-design phase, and use the results to inform the design and construction of the project. The analysis must include at least two potential strategies for each of the following areas: site conditions, massing and orientation, basic envelope attributes, lighting levels, thermal comfort ranges, plug and process load needs, programmatic and operational parameters, outdoor water use, and indoor water use. The project team must also document how the analysis informed the owner’s project requirements, basis of design, and design documents.