LEED Scoring

The LEED Certification System

The LEED (Leadership in Energy and Environmental Design) certification system is a voluntary, market-oriented tool that evaluates the sustainability performance of buildings and developments. LEED was developed by the U.S. Green Building Council (USGBC) and offers different rating systems for various building types and stages. These systems cover diverse sectors such as new construction, existing buildings, residential, schools, retail, data centers, warehouses, hotels and hospitals. LEED certification transparently confirms internationally that a building is environmentally friendly.

LEED Scoring

In LEED certification, projects earn points in specific categories and, as a result, reach one of four certification levels. The scoring system is built on prerequisites and credits. Prerequisites are mandatory requirements that must be met to obtain certification; credits are points earned for practices that improve a project's sustainability performance. The LEED scoring system examines projects' design, construction and operation processes in detail, while also offering many options and considerable flexibility.

In LEED certification, projects are evaluated on a total of 110 points. Points are awarded based on performance across various sustainability categories...

LEED Scoring Terms

Prerequisites

Criteria that must be met for the certificate to be awarded. Even if full points were earned from every credit, certification is not possible unless all prerequisites are satisfied.

Credits

For LEED scoring, each heading carries its own points. Those points are set by USGBC according to the heading's sustainability content, and the accumulated points determine the certification level.

Certification Level

After all prerequisites are met, exceeding the minimum of 40 points earns Certified, 50 earns Silver, 60 earns Gold and 80 earns Platinum certification.

LEED Scoring — Prerequisites

In the LEED certification system, some mandatory requirements must first be met to obtain certification. These requirements are called prerequisites and are expected of all projects. Prerequisites carry no points, but projects that do not meet them cannot earn certification. The prerequisites stated in the sources are:

Environmental Tobacco Smoke Control

• Aims to protect occupants, interior surfaces and ventilation systems from exposure to tobacco smoke.
• Smoking is prohibited inside the building, and designated smoking areas must be at least 7.5 meters (25 feet) from building entrances, outdoor air intakes and operable windows.
• In schools, smoking is prohibited throughout the premises.

Minimum Energy Performance

• Aims to reduce environmental and economic harm by ensuring minimum energy efficiency for the building and its systems.
• Energy savings of 5% for new construction, 3% for major renovations and 2% for core and shell projects must be achieved.
• An energy simulation compliant with ANSI/ASHRAE/IESNA Standard 90.1–2010 (or the local equivalent) must be performed.

Building-Level Energy Metering

• Supports energy management by tracking building-level energy use and identifies additional savings opportunities.
• Energy meters measuring the building's energy consumption (electricity, natural gas, etc.) must be installed.
• The project must share 5 years of energy consumption data with USGBC.

Fundamental Commissioning and Verification

• Aims to ensure building systems meet energy, water, indoor environmental quality and durability requirements.
• A commissioning (Cx) process per ASHRAE guidelines must be applied for mechanical, electrical, plumbing and renewable energy systems.

Fundamental Refrigerant Management

• Supports the use of refrigerants that do not harm the ozone layer and have minimal climate impact.
• Refrigerants used in the project must have zero ozone depletion potential (ODP) and a global warming potential (GWP) below 50.

Indoor Water Use Reduction

• Water savings must be achieved in the building's indoor and outdoor water consumption. 

Building-Level Water Metering

• Permanent water meters measuring the building's total potable water use must be installed.
• Meter data must be summarized monthly and annually, and the project must share 5 years of water use data with USGBC.

Minimum Indoor Air Quality Performance

• Contributes to occupant comfort and health by setting minimum indoor air quality standards.
• For mechanically ventilated spaces, the ventilation requirements of ASHRAE Standard 62.1–2010 (or the local equivalent) must be met.
• For naturally ventilated spaces, ASHRAE 62.1–2010 or CIBSE guidance (or the local equivalent) must be used.
• For healthcare projects, ASHRAE Standard 170–2008 and FGI 2010 guidance apply.

Storage and Collection of Recyclables

Appropriate spaces for the collection and storage of recyclable waste must be provided.

Construction and Demolition Waste Management Plan

• Aims to reduce the amount of waste sent to landfills through recycling, reuse and recovery of construction and demolition waste.
• A plan must be created to recycle or reuse non-hazardous construction and demolition materials.

Construction Activity Pollution Prevention

• Aims to control soil erosion, sedimentation in waterways and airborne dust from construction activities.
• A plan meeting the erosion and sediment control requirements of the 2012 U.S. EPA Construction General Permit (CGP) or the local equivalent must be created and implemented.

LEED Scoring — Credits

In the LEED scoring system, projects that meet the prerequisites can earn points under various credit headings. Credits encourage strategies that help the project reach its sustainability goals. Each credit carries a specific point value, and projects raise their certification level by meeting these credits. In some credits, points are earned by satisfying a single criterion; in others, more points can be earned by demonstrating performance at different levels. You can visit the website covering the LEED scoring system.

Here are some credit headings and how the scoring logic works:

Location and Transportation

The Location and Transportation (LT) category aims to position projects in appropriate places and reduce distances traveled by car. Under this category there are various credits, such as sensitive land protection, surrounding density and diverse uses, access to transit, reduced parking footprint and green vehicles. The sensitive land protection credit aims to prevent development of environmentally sensitive lands. 

The surrounding density and diverse uses credit encourages projects to locate in areas with dense and varied uses, while the access to transit credit aims to ensure projects are near transit stops. The reduced parking footprint credit targets reducing the environmental impact of parking areas, and the green vehicles credit encourages alternative-fuel vehicles. Bicycle facilities also hold an important place in this category and encourage cycling. AECO provides services for all headings and credits within its LEED consultancy.

Sustainable Sites

The Sustainable Sites (SS) category focuses on preventing pollution from construction activities, site assessment, reducing the heat island effect and reducing light pollution. The construction activity pollution prevention prerequisite aims to control erosion and sedimentation during construction. The site assessment credit encourages evaluating site conditions before project design. The heat island reduction credit targets reducing the heat island effect of buildings and parking areas, while the light pollution reduction credit aims to increase access to the night sky and reduce light pollution. This category also includes topics such as protecting or restoring habitat and creating outdoor spaces.

Water Efficiency

The Water Efficiency (WE) category focuses on reducing outdoor and indoor water use. Under Outdoor Water Use Reduction, projects aim to reduce outdoor water consumption — achieved through landscaping that requires no irrigation or reduced irrigation methods. Under Indoor Water Use Reduction, the amount of water used inside the building is reduced through fixture and fitting savings, the use of WaterSense labeled products and alternative water sources. There are also special requirements for water consumption of kitchen and laboratory equipment.

Energy and Atmosphere

The Energy and Atmosphere (EA) category covers fundamental commissioning and verification, building-level energy metering, enhanced commissioning, optimizing energy performance, advanced energy metering, demand response, refrigerant management, and green energy and carbon offsets. The fundamental commissioning and verification prerequisite aims to ensure the proper operation of mechanical, electrical, plumbing and renewable energy systems. The building-level energy metering prerequisite aims to monitor building energy use. The enhanced commissioning credit encourages more comprehensive commissioning of systems beyond the fundamental requirements. 

The optimizing energy performance credit aims to increase energy efficiency, and the advanced energy metering credit aims to monitor energy use at building and system level. AECO completes and reports building energy modeling within its LEED consultancy service. The demand response credit aims to reduce energy demand. The refrigerant management credit targets reducing the use of substances that deplete the ozone layer and contribute to global warming, while the green energy and carbon offsets credit encourages renewable energy sources and carbon offset projects.

Materials and Resources

The Materials and Resources (MR) category covers the storage and collection of recyclable waste, construction and demolition waste management, building life-cycle impact reduction, and building product disclosure and optimization. The storage and collection of recyclables prerequisite aims to recycle waste generated by building occupants. The construction and demolition waste management prerequisite encourages the recovery and reuse of construction and demolition waste. 

The building life-cycle impact reduction credit encourages the reuse of building materials and life-cycle assessment, while the building product disclosure and optimization credit encourages the use of environmental product declarations and the responsible selection of raw material sources. Credits for reducing harmful substances, such as PBT source reduction — mercury and furniture and medical furnishings, also fall under this category.

Indoor Environmental Quality

 The Indoor Environmental Quality (EQ) category focuses on minimum indoor air quality performance, environmental tobacco smoke control, low-emitting materials, a construction indoor air quality management plan, and indoor air quality assessment. The minimum indoor air quality performance prerequisite includes requirements for mechanical and natural ventilation systems. The environmental tobacco smoke control prerequisite aims to prohibit smoking inside and outside the building. The low-emitting materials credit aims to reduce concentrations of chemical pollutants that can affect indoor air quality, while the construction indoor air quality management plan credit aims to manage indoor air quality during construction. 

The indoor air quality assessment credit encourages testing indoor air quality after construction is complete. Credits such as thermal comfort, lighting, daylight and quality views also fall under this category, aiming to increase occupant comfort and health. The acoustic performance credit aims to improve the acoustic properties of spaces.

Innovation

 The Innovation (IN) category encourages projects to demonstrate exceptional or innovative performance. Under this category, projects are encouraged to implement innovative strategies not addressed in the LEED system and to pursue pilot credits. In addition, the LEED Accredited Professional (AP) credit encourages having LEED AP experts on the project team, easing project processes. AECO provides its LEED service through its LEED AP service .