Green Building: Toward a Sustainable Future

The energy efficiency of a building is determined by the energy consumption per square meter of floor area, allowing for comparisons against established benchmarks for common building types. The typical benchmark is the median level of performance of all the buildings in a given category and good practice.

Buildings are integral to our daily lives and are the largest energy consumers and significant carbon dioxide emitters in the EU. EU buildings account for 40% of energy consumption and 36% of greenhouse gas emissions, originating from their construction, use, renovation, and demolition. Today, 85% of EU buildings were constructed before 2000, and 75% of these have poor energy performance, leading to significant energy waste. This issue can be mitigated by retrofitting existing buildings and incorporating smart solutions and energy-efficient materials in new constructions. Energy-efficient buildings lead to lower energy bills and reduced energy demand. Improving the energy performance of buildings not only conserves energy and reduces costs, thus alleviating energy poverty and boosting energy independence, but also enhances the health and wellbeing of citizens by elevating living standards to contemporary levels for everyone.

Enhancing energy efficiency in buildings is essential for energy savings and achieving a zero-emission, fully decarbonized building stock, which is crucial for meeting the European Green Deal’s ambitious goal of carbon neutrality by 2050. EU regulations on building energy efficiency have shown substantial positive impacts. Since the implementation of these measures in national building codes, the energy consumption in modern buildings has been reduced by half compared to typical buildings from the 1980s.

Building Energy Performance Certificate

The energy rating of a building is expressed through several indicators that explain the reasons for good or bad energy performance and provide useful information for making recommendations to improve this performance. These indicators are measured on an annual basis and refer to the unit of useful surface area of the building. They are derived from the energy consumed to meet the needs associated with normal operating and occupancy conditions under specific climatic conditions. This includes energy used for heating, cooling, ventilation, domestic hot water production, and, where applicable, lighting, all aimed at maintaining thermal and light comfort as well as indoor air quality. The main or global indicators of energy efficiency include:

Annual CO₂ equivalent (CO₂eq) emissions: This measures the greenhouse gas emissions associated with the building’s energy consumption.
Annual consumption of non-renewable primary energy: This tracks the amount of non-renewable energy sources consumed by the building annually.

These indicators help in understanding the building’s overall energy performance and highlight areas where improvements can be made. The degree of efficiency depends on various factors, including the local climate, building design, construction methods and materials, systems for heating, ventilation, air conditioning, and hot water, as well as the appliances and equipment used in the building.

An Energy Performance Certificate (EPC) is an official document that indicates a home’s current and potential energy efficiency. It features a rating scale from A to G, with A being the most efficient and cheapest to heat. The EPC also includes a list of recommended actions to improve the home’s energy efficiency.

EPCs are valuable to all stakeholders in the building sector. They provide a mechanism for prospective buyers and tenants to compare the energy efficiency of different buildings or the energy ratings across a range of similar buildings. Additionally, certification allows for a comparison between existing buildings and recent building codes, offering a way to evaluate the efficiency of older buildings relative to newer ones. An EPC is required when selling, letting, or building a home in countries like the UK and Spain.

Taking as an example an EPC for a building in Spain, the certificate is divided into several parts:

Location of the building: Includes the address, climate zone, and other relevant geographical information.
Type of the building: Specifies the building category, such as residential or commercial.
Description of the energy performance of the building: Details the current energy use and efficiency.
Energy rating of the building: Provides the energy efficiency rating on a scale from A (most efficient) to G (least efficient).
Recommendation for energy efficiency improvement: Suggests measures to enhance the building’s energy performance.
Test, checks and inspections carried out by the certifying technician: Lists the evaluations conducted to certify the building.

Green Building Certificates

Green building is a comprehensive process that applies to buildings, their sites, interiors, operations, and the communities in which they are situated. This process spans the entire life cycle of a project, from the initial concept to the end of the building’s life, including the recycling or reuse of its parts. The term green building encompasses several phases:

Planning: Establishing sustainable goals and strategies for the project.
Design: Creating building plans that integrate environmentally friendly practices.
Construction: Utilizing sustainable materials and methods.
Operations: Managing the building efficiently to minimize its environmental impact.
End-of-life: Recycling or renewing building components to reduce waste.

Green building aims to achieve a healthy and dynamic balance between environmental, social, and economic benefits. This holistic approach involves considering natural, human, and economic systems to find solutions that enhance the quality of life for all. Greening the built environment means adopting sustainable practices that improve the well-being of individuals and communities while protecting and preserving natural resources.

The goal of the triple bottom line in the built environment is to create value for all stakeholders, not just a select few. This means that sustainable buildings and communities should:

Environmental Benefits: Use resources efficiently, reduce waste, and minimize the environmental footprint. For example, an energy-efficient building should not only save money but also ensure the well-being of its occupants.
Social Benefits: Promote health, safety, and community well-being. A building should not compromise occupant health, as an energy-efficient building that saves owners money but makes occupants sick is not sustainable.
Economic Benefits: Contribute to the economic stability and prosperity of all involved parties. A material with a small carbon footprint should also be produced ethically, without exploiting workers, as a material made in a sweatshop is not sustainable.

A truly sustainable project ensures that environmental, social, and economic considerations are integrated. For example, an energy-efficient building that saves the owners money but makes the occupants sick is not sustainable, nor is a material that has a small carbon footprint but was made in a sweatshop, nor is an eco-resort that displaces threatened species or local people.

Sustainable building certification are used to assess and recognise buildings which meet certain sustainability requirements or standards. Some of the most well-known green building certificates include: LEED (Leadership in Energy and Environmental Design), Energy Star, BREEAM (Building Research Establishment Environmental Assessment Method), Green Globes, Living Building Challenge, GreenGuard, WELL Building Standard, NABERS, Green Star, CASBEE, VERDE, etc. Two of the main green building certifications in Europe are described below:

BREEAM is an international sustainability standard awarded to a select group of buildings that meet its stringent criteria. BREEAM certification can be obtained in three areas: in-use, building, and new construction & renovation. A BREEAM assessment evaluates a building’s specification, design, construction, and use by using recognized performance measures set against established benchmarks. These measures cover a wide range of categories and criteria, from energy to ecology, focusing on the most influential factors.

LEED is the world’s most widely used green building rating system. It provides a framework for designing, constructing, and operating healthy, highly efficient, and cost-saving green buildings. LEED certification offers environmental, social, and governance benefits. It is applicable to all building types and phases, including new construction, interior fit-outs, operations and maintenance, and core and shell. LEED-certified buildings are recognized for their sustainability and positive impact on the environment and occupants.