LEED Certification

According to data collected in recent studies by the IPCC expert panel, the energy demand of buildings increased by approximately 4% since 2020, the largest increase in the past ten years, causing CO2 emissions from building energy operations to reach an unprecedented peak: around 10 GtCO2, representing an increase of approximately 5% compared to 2020. [1]

However, beyond energy consumption, our buildings are responsible for a series of environmental impacts that include the consumption of non-renewable resources, water impact, greenhouse gas emissions derived from material production processes, construction waste generation, and effects on human health and the environment.

The influence of our buildings on the future of our society is therefore more than evident; and it is in this context that the urgent need arises to generate sustainable, energy-efficient buildings with low environmental impact.

In this context, the building sector has begun a path to reduce its impact, but in order to reduce, we must first measure and quantify each of the impacts that a construction generates on the planet.

The latest update to the EPBD directive (the Energy Performance of Buildings Directive on which the national regulations of European Union member countries are based), approved in March 2023, contemplates for the first time the obligation to declare the global warming potential in buildings, which will include the calculation of various impacts beyond CO2 based on the Level(s) framework for assessing impact throughout a building’s life cycle.

This is a regulation that formalizes the measurement of the built environment’s impact, something that has been done privately for many years through private building sustainability certifications.

Certifications such as LEED, BREEAM, Passivhaus are seals from widely recognized entities in the sector that have developed an extensive track record to position themselves as benchmarks in measuring the environmental impact of construction.

Among all of them, undoubtedly the most prominent and enjoying the greatest international recognition is the American LEED, a certification with over 30 years of experience under the U.S. Green Building Council. In Spain, the first building registered with LEED certification dates back to 2005, and the country has now achieved its third consecutive year as a pioneer in Europe in LEED certification with over 1,000 annual certifications, thanks to the outreach work of GBCe.

This article addresses why LEED Certification is one of the best options for ensuring the reduction of a building’s impact, examining the pros and cons of the certification, the strengths and shortcomings of its evaluation criteria, and the steps to carry it out throughout the project’s evolution.

What is LEED certification?

LEED certification, which stands for Leadership in Energy and Environmental Design, is a private certification system for sustainable buildings developed by the U.S. Green Building Council in 1993.

This Council, being the oldest of its kind in the world, is a private non-profit organization that has gained growing global influence. Its primary mission is to promote sustainability in all phases of a building’s life cycle: from design and construction to the operational phase. The importance and objectives of LEED certification are highlighted in its focus on energy efficiency, responsible use of resources, waste reduction, and the creation of healthy spaces for occupants.

Currently, LEED certification has crossed borders and has a presence in over 30 countries. More than 190,000 projects have undergone the LEED certification process in over 186 countries and territories, demonstrating its global impact in promoting sustainable and environmentally responsible construction practices. [2]

LEED certification objectives

LEED-certified buildings play a fundamental role in the fight against climate change and in meeting ESG (environmental, social, and governance) objectives and SDGs, while improving resilience and promoting more equitable communities. LEED represents a holistic approach that is not limited to a single aspect of the building, such as energy efficiency, water use, or air quality. Rather, it encompasses a comprehensive vision that considers all critical elements that interact to create buildings of the highest quality.

Within the LEED system, 35% of credits are intended to address climate change, 20% directly impact human health, 15% focus on water resource management, 10% aim to protect biodiversity, another 10% is related to the green economy, and the remaining 5% concentrates on community impact and natural resources. With LEED v4.1, most credits focus on reducing both operational carbon and embodied carbon, thus reflecting the growing importance of addressing carbon emissions throughout the entire life cycle of buildings. [3]

What types of buildings can achieve it?

LEED certification applies to a wide range of construction types and uses, allowing both new construction and comprehensive renovations to obtain it. With a total of 21 adaptations designed for different contexts, this certification encompasses various areas of construction, including:

– Building Design and Construction (BD+C): For new construction or major renovations. Includes new construction, core and shell.

– Interior Design and Construction (ID+C): For complete interior fit-out projects, including commercial interiors.

– Building Operations and Maintenance (O+M): For existing buildings that are being improved or that require little or no construction work.

– Neighborhood Development (ND): For new land development projects or redevelopment projects containing residential, non-residential uses, or a combination of both. Projects can be at any stage of the development process, from conceptual planning to construction.

– Homes: For single-family homes, low-rise multifamily (one to three stories), or mid-rise multifamily (four or more stories). Homes and residential buildings with more than four stories may also use the LEED BD+C rating system.

– Cities: For entire cities and subsections of a city. LEED for Cities projects can measure and manage water consumption, energy use, waste, transportation, and human experience in the city.

This flexibility allows a wide range of projects, from individual homes to entire cities, to benefit from the sustainability guidelines and standards established by LEED certification.

Building phases

To ensure effective application of LEED certification throughout a building’s entire life cycle, the system distinguishes three key phases: discovery, design and construction, and operational phase.

– Discovery Phase: is fundamental, as it establishes the foundations for project success. During this stage, a comprehensive analysis of the natural resources available in the area is carried out, following the principles of bioclimatic architecture. This approach allows understanding the environment in which the building will be developed and considering how to maximize its energy efficiency and environmental impact from the outset.

– Design and construction phase: translates the findings and learnings obtained during the discovery phase into a schematic design. All previous considerations are integrated to ensure that the building is efficient, sustainable, and environmentally responsible. It is during this stage that decisions made regarding materials, technologies, and construction practices that meet LEED standards are materialized.

– Building operational phase: during this stage, the actual impact of building use is measured and feedback mechanisms are implemented to identify opportunities for continuous improvement and optimization. It is essential to monitor the building’s performance over time, identifying areas for improvement and taking corrective measures as necessary to maintain or improve its efficiency and sustainability over time.

In summary, the effective application of LEED certification requires an integrative approach that encompasses all stages of the building’s life cycle, from initial discovery to the ongoing operational phase, thus ensuring its positive impact on the environment and the community.

What indicators does it analyze?

LEED certification establishes a reference guide, currently version v4 on the path to implementing v5, of which a draft has already been developed [4].

This document details how to analyze a series of key indicators to evaluate the sustainability and environmental performance of a building [5]. These indicators are grouped into different categories, each of which establishes requirements to promote sustainable and efficient practices.

The LEED rating system uses a comparative label based on the sum of credits obtained through compliance with its objectives and requirements. Exemplary maximum performance is defined as the highest standard that can be achieved, incentivizing excellence in sustainable design and construction.

Below, we detail the different categories and their main objectives present in the Building Design and Construction (BD+C) guide, which demonstrate that LEED certification not only focuses on energy efficiency and ecological impact, but also addresses aspects related to occupant quality of life and overall environmental well-being.

– Integrative process: Conducting an early analysis of the interrelationships between systems allows maximizing opportunities for the integrated and cost-effective adoption of sustainable design and construction strategies, emphasizing human health as a fundamental evaluative criterion for building design, construction, and operational strategies.

– Location and transportation: To ensure responsible development, the selection of appropriate locations is promoted, vehicle use is reduced, and quality of life is improved by promoting daily physical activity. Environmental conservation is emphasized by avoiding construction in sensitive areas and encouraging development in areas with existing infrastructure. Additionally, sustainable mobility is promoted and the aim is to minimize environmental impacts associated with motor vehicle use. Together, these measures seek to protect the environment, promote an active lifestyle, and reduce air pollution.

– Sustainable sites: The certification seeks to protect the health of vulnerable populations by assessing environmental pollution at the site. Sustainable options in site design are considered to conserve and restore natural habitats, promote biodiversity, and encourage interaction with the environment. Water management and runoff reduction are prioritized to improve water quality and replicate the site’s natural hydrology. Additionally, impacts on microclimates and human and wildlife habitats are minimized, access to the night sky is promoted, and sustainable benefits are ensured to endure despite future changes.

– Water efficiency: To reduce water consumption inside and outside the building, through measurement and monitoring of its consumption and identification of additional water-saving opportunities such as reducing irrigation needs, appliance efficiency, and reuse strategies.

– Energy and atmosphere: To support the design, construction, and eventual operational phase of a project that meets requirements for energy, water, indoor environmental quality, and durability, the aim is to reduce environmental and economic damage resulting from excessive energy use by achieving minimum energy efficiency levels for the building and its systems. Energy management is supported and additional energy-saving opportunities are identified through monitoring energy use at the building and system level. Additionally, the aim is to improve energy efficiency beyond basic standards, increase self-generation of renewable energy, reduce greenhouse gas emissions, and encourage participation in demand response technologies and energy efficiency programs.

– Materials and resources: To reduce waste generated both in building construction and by its occupants throughout its operational phase and resulting from its demolition at the end of its useful life through proper waste management. The reduction of products and devices containing mercury is promoted, as well as the use of products with life cycle information that have a reduced environmental impact. Additionally, the selection of products from manufacturers who have verified improvements in life cycle environmental impacts, have been responsibly sourced, and minimize the use of harmful substances is rewarded.

– Indoor environmental quality: Contribute to occupant comfort and well-being by establishing minimum standards for indoor air quality such as acoustic comfort, thermal comfort, low material emissions, and adequate lighting, all aimed at improving occupant well-being and productivity.

– Innovation: Encourage projects to achieve exceptional performance, using innovative approaches and techniques for sustainable design and construction.

– Regional priority: Provide an incentive for achieving credits that address environmental priorities specific to geographic location, social equity, and public health.

Evaluation method

LEED certification offers four rating levels: Certified, Silver, Gold, or Platinum, depending on the performance obtained in the evaluation. The documentation required for verification is submitted after the design phase and again during the construction phase, ensuring that the project has been executed in accordance with established standards. It is crucial to conduct on-site verifications rather than relying solely on plans, thus ensuring actual project compliance.

To adapt to local particularities, the guide includes a section on international tips that allow determining equivalence with U.S. standards using local regulations. In some circumstances, alternatives to LEED standards specific to the project’s location are offered, ensuring similar or even superior results.

The USGBC highlights that LEED Certification can lead to a significant reduction in energy consumption (between 30% and 70%), water (30% to 50%), waste costs (between 50% and 80%), and CO2 emissions (35%). In addition to environmental benefits, energy efficiency also brings economic advantages, as LEED projects not only reduce energy expenses and improve the health of their interior environments, but also increase the rental value and resale value of certified buildings.