Sustainable or green design is quickly becoming a high priority, and even a standard, for many building owners today. The U.S. Green Building Council (USGBC) provides a measurement of sustainable design through a point system of the LEED Green Building Rating System (LEED). Of the 69 points available, a project may attain LEED Certification by obtaining 26 points; a Silver rating with 33 points; a Gold rating with 39 points; and a Platinum Level rating with 52 points.

As the number of buildings seeking and attaining LEED certification is growing, we have learned that Platinum Level ratings are being attained through significant synergies between the designer and contractor. This article focuses on the latest LEED Version 2.2 requirements and how specific point requirements may have a major effect on your LEED-designed and -constructed project.

LEED categories include credits, prerequisites and points as follows:
Category                                     Credits              Prereq                     Points
Site Selection                                  8                                                          14
Water Efficiency                             3                                                            5
Energy and Atmosphere                 6                          3                               17
Materials and Resources               7                           1                              13
Indoor Environmental Quality       8                          2                               15
Innovation and Design Process     2                                                            5

The prerequisites must be met to obtain LEED certification. In order to provide an overview of LEED points as well as a greater understanding of the electrical interface to achieving LEED certification, each category is identified and divided in two areas: the first includes credits which have “limited or no electrical interface with LEED credit”; the second includes credits which have “electrical design interface with LEED Credit.”

Site Selection

The McKinney Green Building also has plug-in stations for hybrid and electric vehicles. Photography by Randy Hagen.

Limited or No Electrical Interface with LEED Credit
The Electrical interface may include providing additional lighting to support functions (i.e., bicycle racks) or providing power to an irrigation system which may be removed within one year after plant development.

• SS Prerequisite 1: Construction Activity Pollution Prevention
• SS Credit 2: Development Density
• SS Credit 3: Brownfield Redevelopment
• SS Credit 4.1: Alternative Transportation, Public Transportation Access
• SS Credit 4.2: Alternative Transportation, Bicycle Storage and Changing Rooms
• SS Credit 4.4: Alternative Transportation, Parking Capacity
• SS Credit 5.2: Site Development: Maximize Open Space
• SS Credit 6.1: Storm water Design: Quantity Control
• SS Credit 6.2: Storm water Design: Quality Control
• SS Credit 7.2: Heat Island Effect, Roof

Electrical Design Interface with LEED Credit

At the McKinney Green Building in Texas, special parking spaces are designated for carpoolers. Photography © Mark Trew.

SS Credit 4.3: Alternative Transportation: Low Emitting & Fuel Efficient Vehicles

• One option is to provide re-fueling locations for 3 percent of the parking spaces; electric cars would need a power location with a power receptacle type that may not be known at the time of design. At a minimum, a rough-in location would be required at the early phases of the parking garage construction

SS Credit 5.1: Reduced Site Disturbance, Protect or Restore Habitat

• Specific site disturbance requirements are noted. The site may only be disturbed 10 feet on either side of utilities 12 inches and less, 15 feet on either side of main utilities, 25 feet on either side of parking or staging areas, and 40 feet around the building perimeter. These requirements will need to be carefully coordinated with the general contractor.

SS Credit 7.1: Heat Island Effect, Non-roof

• One option under this credit is 50 percent “tuck-under” parking. Of course the lighting design, associated signage or access control may be different for a parking garage versus on grade parking.

SS Credit 8: Light Pollution Reduction

• This lighting design intensive credit focuses on energy consumption which exceeds ASHRAE 90.1 requirements, lighting control inside the building, limiting (or eliminating) up-lighting and consistent lighting cut-off requirements at the property line. The purpose of this credit is to increase night sky access, improve night-time visibility, and reducing nocturnal environmental impact. The intensive requirements of Credit 8 are very detailed.

Water Efficiency

Limited or No Electrical Interface with LEED Credit The Electrical interface may include providing power to toilet fixtures or providing power to an irrigation system which may be removed in one year after plant development.

• WE Credit 1.1: Water Efficient Landscaping, Reduce by 50 percent
• WE Credit 1.2: Water Efficient Landscaping, No Potable Water Use or No Irrigation
• WE Credit 2: Innovative Wastewater Technologies
• WE Credit 3.1: Water Use Reduction, 20 percent Reduction
• WE Credit 3.2: Water Use Reduction, 30 percent Reduction

Electrical Design Interface with LEED Credit: None

Energy And Atmosphere

Limited or No Electrical Interface with LEED Credit
The Electrical interface may include the support of different mechanical technologies for refrigeration design.

• EA Prerequisite 3: Fundamental Refrigerant Management
• EA Credit 4: Enhanced Refrigerant Management

Electrical Design Interface with LEED Credit

At the Banner Bank Building in Boise, Idaho, all power and telecomm connections are found in power boxes mounted in the raised floor. Photography © Deborah Hardee.

EA Prerequisite 1: Fundamental Commissioning of the Building Energy Systems

• Typically the complicated systems which required specialized training for the owner are included in the commissioning process, including the lighting control system, power monitoring system, generator/ATS/paralleling switchgear system, and on-site renewable energy systems. It all starts with assigning a commissioning authority, then developing the owners project requirements, and basis of design. These commissioning are incorporated into the contract documents and a commissioning plan is developed. The installation and performance is then verified and documented.

EA Prerequisite 2: Minimum Energy Performance

• Meeting the lighting and power requirements of ASHRAE 90.1 or similar local code is mandated.

EA Credit 1: Optimize Energy Performance

• Further to EA Prerequisite 2 (Minimum Energy Performance), Optimizing Energy Performance in addition to ASHRAE 90.1 from a minimum of 10.5 percent, up to 42 percent for new buildings will gain from one to 10 points. Achieving this level of energy savings may have a significant impact on the building electrical service size. Another way mechanical designers achieve these credits is with an under-floor air distribution system which may change power and telecommunications distribution (also to an under-floor system).

A 45 kW photovoltaic system at the McKinney Green Building supplies approximately 10 percent of the building’s electrical energy needed. Photography © Mark Trew.

EA Credit 2: On-Site Renewable Energy

• Up to thee points are available for on-site renewable energy from sources including photovoltaics , solar thermal systems, bio-fuel systems, geo-thermal heating and electric systems, and low impact hydro-electric systems. Note that ineligible sources are passive solar and daylighting strategies, and ground source heat pumps.

EA Credit 3: Enhanced Commissioning

• In addition to the Prerequisite, Enhanced Commissioning includes Design Review and Contract Submittal Review, the Development of a Systems Manual and Owner Training, and finally a Review of Building operation within 10 months after substantial completion.

Credit 5: Measurement and Verification

• Evaluating the energy efficiency by comparing the actual to baseline or design performance of the building for one year after occupancy will require data on meters and monitors included in the design.

Credit 6: Green Power

• The Green Power credit is based on purchasing 35 percent green power from the utility on a two-year contract. The owner may need estimates of demand load and kWh usage to quantify the cost for this credit.

Materials And Resources

Limited or No Electrical Interface with LEED Credit The electrical interface may include the support mechanical equipment for dedicated exhaust. Note that electrical equipment may not be included in many of these credits, although other electrical components including wire, conduit and other materials may be attributable to the Construction Waste or Regional Materials Credits.

• MR Prerequisite 1: Storage & Collection of Recyclables
• MR Credit 1.1: Building Reuse, Maintain 75 percent of Existing Walls, Floors & Roof
• MR Credit 1.2: Building Reuse, Maintain 95 percent of Existing Walls, Floors & Roof
• MR Credit 1.3: Building Reuse, Maintain 50 percent of Interior Non-Structural Elements
• MR Credit 2.1: Construction Waste Management, Divert 50 percent from Disposal
• MR Credit 2.2: Construction Waste Management, Divert 75 percent
• MR Credit 3.1: Materials Reuse, 5 percent
• MR Credit 3.2: Materials Reuse, 10 percent
• MR Credit 4.1: Recycled Content:10 percent (post-consumer + 1/2 pre-consumer)
• MR Credit 4.2: Recycled Content:20 percent (post-consumer + 1/2 pre-consumer)
• MR Credit 5.1: Regional Materials: 10 percent Extracted, Processed & Manufactured Regionally
• MR Credit 5.2: Regional Materials: 20 percent Extracted, Processed & Manufactured Regionally
• MR Credit 6: Rapidly Renewable Materials
• MR Credit 7: Certified Wood

Electrical Design Interface with LEED Credit
None

Indoor Environmenal Quality

Limited or No Electrical Interface with LEED Credit
The Electrical interface may include an interface with mechanical components in achieving a credit such as increased mechanical AHU load to achieve increased ventilation, or confirming that equipment paint utilizes low-emitting paint.

• EQ Prerequisite 1: Minimum IAQ Performance
• EQ Prerequisite 2: Environmental Tobacco Smoke (ETS) Control
• EQ Credit 1: Outdoor Air Delivery Monitoring
• EQ Credit 2: Increase Ventilation
• EQ Credit 3.1: Construction IAQ Management Plan - During Construction
• EQ Credit 3.2: Construction IAQ Management Plan - Before Occupancy
• EQ Credit 4.1: Low-Emitting Materials, Adhesives and Sealants
• EQ Credit 4.2: Low-Emitting Materials, Paints & Coatings
• EQ Credit 4.3: Low-Emitting Materials, Carpet Systems
• EQ Credit 4.4: Low-Emitting Materials, Composite Wood and Agrifiber Products
• EQ Credit 5: Indoor Chemical and Pollutant Source Control (con't)
• EQ Credit 6.2: Controllability of Systems, Thermal Comfort
• EQ Credit 7.1: Thermal Comfort, Design
• EQ Credit 7.2: Thermal Comfort, Verification
• EQ Credit 8.2: Daylight and Views, Daylight 90 percent of Spaces

Electrical Design Interface with LEED Credit
EQ Credit 6.1: Controllability of Systems, Lighting

• Individual comfort drives an intent of a high level of lighting control, and a requirement of individual lighting controls for 90 percent of the building occupants to suit their individual task needs. Multiple levels of lighting is desired, but at a minimum 90 percent of occupants in private offices, open plan workstations, reception stations, etc. need to be able to turn the task light on and off.

EQ Credit 8.1: Daylight and Views, Daylight 75 percent of Spaces

• Realizing the benefits of daylighting for personnel comfort can also provide energy savings with a daylight harvesting lighting control system.

Innovation And Design Process

The Trimont Area Wind Farm in Minnesota is one of the largest farmer-owned wind farm projects in the nation.

The innovation in design credits focus on exemplary performance in an existing credit, or an avenue to receive a point not associated with an existing credit. Additionally, the LEED Accredited Professional credit requires that one principal participant of the project team be a LEED AP.

Early coordination between the owner, project design team, and general contractor and subcontractors are critical to the implementation of a successful LEED-certified project. Many of the points reviewed are either typical of today’s design standards or may be accomplished with no additional cost. Other points may be accomplished with minor up-front costs. The question for the team is the points, which require a substantial up-front cost with or without a short-term payback. In any case, it is imperative that concepts or strategies to achieve points are thoroughly discussed early in the project design phase to best assess all options to achieve a desired outcome for the Owner based on their budgetary constraints. It all starts with LEED awareness.